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  • Springer  (349,671)
  • 1995-1999  (339,256)
  • 1945-1949  (10,415)
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  • 1
    Electronic Resource
    Electronic Resource
    Biology of the stingless beePlebeia remota (Holmberg): observations and evolutionary implications (1995)
    Springer
    Insectes sociaux 42 (1995), S. 71-87 
    Details
    ISSN: 1420-9098
    Keywords: Stingless bees ; Plebeia remota ; social evolution ; division of labour
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The genusPlebeia has a special significance for the study of social evolution of stingless bees: morphologically primitive, its species display a wealth of behavioural evolution, especially with respect to the oviposition process. We comparePlebeia remota with the few other members of the genus studied so far. Related to its subtropical geographical range, brood production is seasonal (there is no brood in the colony in colder months), and adult workers occur as summer and winter bees. The nest is in tree cavities, and the involucrum is absent or restricted to the winter period. Brood cells are arranged in horizontal combs, and new cells are built completely synchronously. Each series consists of up to 50 cells, their number being mainly dependent on colony size. Construction speed is remarkably constant, allowing 4–6 batches per 24 hours. Cell building and provisioning are activities of a small group of specialized workers. The oviposition cycle follows the classical subdivisions for stingless bees. During the patrolling phase a worker may “offer” a trophic egg in a most remarkable way: while retreating backward from the queen she bends the abdomen under thorax and head, and lays an egg on the comb. This egg is eaten by the queen or a worker. The provisioning, oviposition and operculation of all cells occur simultaneously, each cell is provisioned by 4–9 workers. Localization of a cell by the queen may be facilitated by its characteristic guard, which “defends” the cell against the approaching queen. The degree of synchronization within a batch is very high: the duration per cell lasts 420–950 sec, the batch of up till 50 cells needs only 557–1160 sec. Operculation is done by a worker that was not involved in the previous steps. Males are generally produced by the queen. Several male producing cycles per year occur. In orphan colonies laying workers give rise to males, and in queenright colonies workers may occasionally reproduce as well. Division of labour follows the general pattern for stingless bees; however, cell building and provisioning are activities of a specialized group of workers.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01245700
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  • 2
    Electronic Resource
    Electronic Resource
    Suppression of queen rearing in European and Africanized honey beesApis mellifera L. by synthetic queen mandibular gland pheromone (1995)
    Springer
    Insectes sociaux 42 (1995), S. 113-121 
    Details
    ISSN: 1420-9098
    Keywords: Apis mellifera ; queen pheromone ; queen rearing ; monogyny ; Africanized
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Queen rearing is suppressed in honey bees (Apis mellifera L.) by pheromones, particularly the queen's mandibular gland pheromone. In this study we compared this pheromonally-based inhibition between temperate and tropically-evolved honey bees. Colonies of European and Africanized bees were exposed to synthetic queen mandibular gland pheromone (QMP) for ten days following removal of resident queens, and their queen rearing responses were examined. Queen rearing was suppressed similarly in both European and Africanized honey bees with the addition of synthetic QMP, indicating that QMP acts on workers of both races in a comparable fashion. QMP completely suppressed queen cell production for two days, but by day six, cells containing queen larvae were present in all treated colonies, indicating that other signals play a role in the suppression of queen rearing. In queenless control colonies not treated with QMP, Africanized bees reared 30% fewer queens than Europeans, possibly due to racial differences in response to feedback from developing queens and/or their cells. Queen development rate was faster in Africanized colonies, or they selected older larvae to initiate cells, as only 1 % of queen cells were unsealed after 10 days compared with 12% unsealed cells in European colonies.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01242447
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  • 3
    Electronic Resource
    Electronic Resource
    Drone congregations apart from the nest inMelipona favosa (1995)
    Springer
    Insectes sociaux 42 (1995), S. 123-127 
    Details
    ISSN: 1420-9098
    Keywords: Drone congregation area ; sexual behaviour ; chemical communication ; male competition ; Meliponinae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary This is a first behavioural description of a large non-nest associated drone congregation of the stingless beeMelipona favosa. The about 400 drones had originated from different nests. The males interacted aggressively. Several gynes arrived at the drone congregation area (DCA). Olfactory stimuli triggered specific behaviours of the males as well as of the gynes but matings were not observed at the DCA.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01242448
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  • 4
    Electronic Resource
    Electronic Resource
    Unique habits of stomodeal trophallaxis in the ponerine antHypoponera sp. (1995)
    Springer
    Insectes sociaux 42 (1995), S. 137-144 
    Details
    ISSN: 1420-9098
    Keywords: Stomodeal trophallaxis ; Ponerinae ; ergatoid male ; ergatoid queen ; Hypoponera
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The present paper describes for the first time that adult-to-adult trophallaxis exists in ponerine ants. Furthermore, it shows that the adult castes of the ponerine andHypoponera sp. have different habits of trophallaxis. Workers display a soliciting behavior toward queens, males and workers, but receive regurgitated food only from workers. The workers are forced to stop soliciting for regurgitated food by the “whipping behavior” of the queen. Callow queens solicit regurgitated food from workers and ergatoid males and receive it, while mature queens do not solicit regurgitation from workers. Ergatoid males receive regurgitated food from workers and regurgitate it to queens. Alate males show no trophallactic food exchange with workers and queens. Trophallactic behavior was never observed between males of either winged or ergatoid types.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01242450
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  • 5
    Electronic Resource
    Electronic Resource
    Distribution of humic compounds in mounds of some soil-feeding termite species of tropical rainforests: its influence on soil structure stability (1995)
    Springer
    Insectes sociaux 42 (1995), S. 167-185 
    Details
    ISSN: 1420-9098
    Keywords: Soil-feeding termites ; tropical rainforest ; humic compounds ; structural stability
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary A comparison was made of some physicochemical characteristics of epigeous termitaries (nest walls and surrounding horizons) of four species of soil-feeding termites living in tropical rainforests. Our aim was to determine whether these species affect the different compounds involved in the structural stability of soil in a similar manner. Our data support the general finding that the structural stability of soil is correlated with organic matter, cations and the relative proportion of mineral elements. Of these parameters, the content of organic matter is the most significant factor effecting the stability of termite building materials. Analysis of humic compound distribution revealed that fulvic and humic acids, owing to their electrochemical properties, are highly involved. Also, the organic matter in termitaries is more polymerized than that of humiferous control horizons, leading to FA/HA ratios close to 1. The stability of nest walls and topsoils differs between the species. Generally, the speciesNoditermes lamanianus, Thoracotermes macrothorax andCubitermes fungifaber build nests that are enriched with organic matter and exchangeable cations, resulting in high structural stability. In contrast, materials worked byCrenetermes albotarsalis are not enriched with organic matter or cations and do not differ in stability from the control soils. It is concluded that any generalization on the overall influence of soil-feeding termites on soil fertility might be misleading. Only species which enrich their materials with organic matter, especially stabilised humic acids, contribute to soil conservation and hence fertility. Once the termitary is dead, its organic matter is again available to the soil ecosystem.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01242453
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  • 6
    Electronic Resource
    Electronic Resource
    Haplometrosis and pleometrosis in the antAcromyrmex striatus (Hymenoptera: Formicidae) (1996)
    Springer
    Insectes sociaux 43 (1996), S. 47-51 
    Details
    ISSN: 1420-9098
    Keywords: Colony foundation ; haplometrosis ; pleometrosis ; Acromyrmex striatus ; Attini
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Laboratory tests with mated females of the leaf-cutting antsAcromyrmex striatus (Myrmicinae, Attini) were conducted to determine if the colony foundation is a solitary or a mutualistic process. We have also tested the effect of foundresses density and number of available areas in this process. Three bioassays were performed: with single foundresses; with paired foundresses; and with groups of 8 to 18 foundresses. The results suggest that the foundation can be by haplometrosis or pleometrosis, possibly depending on physical distances between or densities of foundresses. Foraging activity was common in haplometrotic queens and in foundress pairs, but no foraging occurred in groups of foundresses.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01253955
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  • 7
    Electronic Resource
    Electronic Resource
    Rediscovery of the workerless inquiline antPogonomyrmex colei and additional notes on natural history (Hymenoptera: Formicidae) (1996)
    Springer
    Insectes sociaux 43 (1996), S. 69-76 
    Details
    ISSN: 1420-9098
    Keywords: Interspecific trail following ; workerless inquiline ant ; Pogonomyrmex colei ; reproductive biology ; seed-harvester ants
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Pogonomyrmex colei is a workerless inquiline ant known only from nests ofP. rugosus, its closest relative. Ten of 776 (1.3%) host nests were parasitized at a site in central Arizona, while none of 1499 potential host colonies were parasitized at two other locales. Colonies ofP. colei are perennial, and host alate females in 9 of 10 colonies demonstrates that host queens survive parasitism. Three of 10 colonies died over 19 colony years of observation, while only 1 of 601 colonies became newly parasitized. Mating occurs in morning for up to 2–3 days following summer and fall rains and in afternoon during cool fall days. Mating is intranidal just outside the nest entrance, with males returning to the natal nest. MaleP. colei may be flightless because their wing area is reduced compared to host males. Females fly from the nest and locate potential host colonies by following trunk trails. Workers are the largest barrier to nest establishment, as they removed over 90% ofP. colei females placed in trunk trails or that entered host nests. Males and females ofP. colei andP. anergismus, the only other congeneric inquiline species, are diminutive compared to their hosts, with females 30% lighter than host workers. Fat content is lower and water content is higher inP. colei andP. anergismus females than in their hosts.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01253957
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  • 8
    Electronic Resource
    Electronic Resource
    An unusual ant diet:Cataglyphis floricola feeding on petals (1996)
    Springer
    Insectes sociaux 43 (1996), S. 101-104 
    Details
    ISSN: 1420-9098
    Keywords: Cataglyphis floricola ; diet ; food resources ; petal consumption
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary C. floricola is an endemic species from the southern Iberian Peninsula which collects large amounts ofHalimium halimifolium petals. Laboratory and field observations confirm that both workers and larvae feed on these petals, which represent an important food resource forC. floricola colonies. This petal consumption is a very unusual ant diet.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01253960
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  • 9
    Electronic Resource
    Electronic Resource
    Polyethism within hunters of the ponerine ant,Ectatomma ruidum Roger (Formicidae, Ponerinae) (1996)
    Springer
    Insectes sociaux 43 (1996), S. 111-118 
    Details
    ISSN: 1420-9098
    Keywords: Predation ; polyethism ; food exchange ; behavioral flexibility ; Ectatomma ruidum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary During laboratory experiments, two categories of prey-foraging workers were found inEctatomma ruidum: stingers and transporters. When numerous live drosophila were offered to the ants, one group of hunters specialized in killing the prey and another in transporting simultaneously the dead drosophila to the nest. Sometimes, there was a transfer of prey by a stinger towards a transporter, after an active soliciting of the transporter by antennation or by using the forelegs. We found high positive correlations between the colony size and the number of ants in each subcaste. A negative correlation existed between the colony size and the proportion of hunters. However, the proportion of workers in the two behavioral subcastes of hunters was stable in spite of differences in colony size. The phylogenetic interest of this type of cooperative predation is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01242563
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  • 10
    Electronic Resource
    Electronic Resource
    Resource choice of social wasps: influence of presence, size and species of resident wasps (1999)
    Springer
    Insectes sociaux 46 (1999), S. 131-136 
    Details
    ISSN: 1420-9098
    Keywords: Key words:Vespula, Polistes, Vespidae, foraging, resource choice.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary: The role of visual cues provided by resident wasps on resource choice by yellowjacket and paper wasp foragers was investigated. Large spring queen yellowjackets and small early season yellowjacket foragers (Vespula germanica, Vespula maculifrons, and Vespula vidua) were extracted in hexane to remove odors and posed as though feeding at petri dish feeders bearing daisy-like flower models, equipped with microcapillary feeding tubes, and containing 1:3 honey:water solution. An array of five feeders was presented to foragers at a suburban and a woodland site in Saratoga Springs, New York. The visual cues provided by resident wasps influenced resource choice by approaching social wasp foragers. Vespula germanica, an introduced yellowjacket species that tends to dominate at rich resources, was the only wasp visiting the suburban feeders. Foragers of this species preferentially fed on feeders and flowers with posed wasps and fed most often next to large wasps. Polistes fuscatus foragers at the woodland site similarly preferred to feed on occupied feeders and flowers. Vespula maculifrons and V. consobrina preferentially visited unoccupied feeders. Individual V. maculifrons, V. consobrina and V. vidua foragers that landed on occupied feeders all preferentially visited unoccupied flowers on those feeders. Vespula vidua and V. flavopilosa foragers did not demonstrate a feeder preference based on the presence/absence of posed wasps. Vespula consobrina foragers that visited occupied feeders preferred those occupied by extracted V. maculifrons queens and workers; no other wasps showed species based landing preferences.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s000400050123
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  • 11
    Electronic Resource
    Electronic Resource
    Paternity and maternity frequencies in Apis mellifera sicula (1999)
    Springer
    Insectes sociaux 46 (1999), S. 137-145 
    Details
    ISSN: 1420-9098
    Keywords: Key words: Mating frequency, polyandry, Apis mellifera sicula, honey bees, microsatellite.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary: Honey bee queens have been shown to mate with a high number of males, but the evolutionary advantage of this high degree of polyandry is still unclear. Mating data from a number of different Apis species and subspecies are needed to help explain polyandry in honey bees. Pupae of four colonies of Apis mellifera sicula from Sicily were genotyped on three polymorphic microsatellite loci. The genotypes of the queens and fathering drones from these colonies were deduced from the genotypes of the pupae. We found no evidence for polygyny, at least we can exclude more than one functional queen, even super-sister queens, if maternity contributions are equal. The four queens mated with at least 5 to 12 (mean: 9.3 ± 3.0 SE) drones. We estimate the error in our determination of the mating frequency that is caused by limited genetic resolution of the marker loci to be less than 1 mating given that Hardy-Weinberg assumptions are satisfied. However, the drones the single queens mated with may be a non-random sample of the whole population, so that detection error may be more severe. The average pedigree relatedness among workers within the colonies was estimated to be 0.341. These results are within the range of those found in other A. mellifera subspecies and Apis species except A. dorsata. We speculate that mating frequency may be positively correlated with drone density.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s000400050124
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  • 12
    Electronic Resource
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    Worker size variation and the evolution of an ant-plant mutualism: Comparative morphometrics of workers of two closely related plant-ants, Petalomyrmex phylax and Aphomomyrmex afer (Formicinae) (1999)
    Springer
    Insectes sociaux 46 (1999), S. 171-178 
    Details
    ISSN: 1420-9098
    Keywords: Key words: Worker polymorphism, ant-plant interaction, mutualism, morphometrics.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary: We compared intranidal variation in worker size in the two closely related plant-ants Aphomomyrmex afer and Petalomyrmex phylax. Each of these genera is monotypic, and the two appear to be sister species among extant ants. Workers of A. afer are larger on average and exhibit much greater intranidal size variation. Workers of P. phylax are smaller and much less variable in size. Both species show weak allometry for some pairs of characters. Head shape is also different in workers of the two species. We discuss these differences in relation to the ecology of A. afer and P. phylax, and propose a scenario for the evolutionary divergence of worker morphology in these two species. Based on comparisons of these two monotypic genera with related ants, we suggest that reduced intranidal variation in worker size is a derived trait in Petalomyrmex.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s000400050129
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  • 13
    Electronic Resource
    Electronic Resource
    Nestmate recognition in the stingless bee Melipona panamica (Apidae, Meliponini) (1999)
    Springer
    Insectes sociaux 46 (1999), S. 208-218 
    Details
    ISSN: 1420-9098
    Keywords: Key words:Melipona panamica, stingless bees, Apidae, nestmate recognition, worker oviposition.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary: Nestmate recognition was studied in the Neotropical stingless bee Melipona panamica, a species in which workers “sneak” their own reproductive eggs into 1 % of brood cells. We manipulated four factors that could influence individual recognition cues: the mother queen, the environment during the immature stage, the environment during the early adult stage, and worker age. We also simulated the action of natural enemies on colonies tested for discrimination of such worker characteristics. All factors that we tested affected responses of the discriminating workers, which could recognize sisters, nieces and unrelated workers. Previous exposure of unrelated callow bees to the odor of the host nest greatly increased chances of acceptance by the host colony. Probability of acceptance decreased, however, with increasing age of introduced bees or increasing disturbance of the host colony. These complexities in patterns of nestmate recognition and nest defense are adequately explained from the standpoint of inclusive fitness of the discriminating workers. Differences in nestmate recognition and worker egg laying among Meliponini are also discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s000400050136
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  • 14
    Electronic Resource
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    Polygyny via unrelated queens indicated by mitochondrial DNA variation in the Australian meat ant Iridomyrmex purpureus (1997)
    Springer
    Insectes sociaux 44 (1997), S. 7-14 
    Details
    ISSN: 1420-9098
    Keywords: Key words: Mitochondrial DNA, restriction site polymorphism, meat ants, Iridomyrmex purpureus, polygyny.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary: The Australian meat ant Iridomyrmex purpureus is known from observations and allozyme surveys to have a high proportion of mature colonies polygynous, but very few incipient ones. Sixteen colonies in the vicinity of Maryborough, Victoria, revealed four mtDNA restriction site haplotypes. One of these nests presented two different haplotypes; given the haplotype frequencies, this result suggests that a high proportion of mature nests contain unrelated queens.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s000400050018
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  • 15
    Electronic Resource
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    Nesting biology of the mangrove mud-nesting ant Polyrhachis sokolova Forel (Hymenoptera, Formicidae) in northern Australia (1997)
    Springer
    Insectes sociaux 44 (1997), S. 15-21 
    Details
    ISSN: 1420-9098
    Keywords: Key words: Mangrove, ants, Polyrhachis sokolova, nest, inundation, foraging.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary: The nest sites of the mud-nesting ant Polyrhachis sokolova were studied in Darwin Harbour mangroves. They were found from the Ceriops tagal zone to the Rhizophora stylosa zone at elevations ranging from 7.22 to 5.99 meters above the lowest astronomical tide (LAT), which means that the nests were inundated in 13‐61% of all high tides and for durations of up to 3.5 hours. The nest structure was studied by excavating nests and making a cast of the galleries using polyurethane foam. The nests were quite extensive, normally with two elevated nest entrances and galleries down to depths of 45 cm. The loose soil particles at the nest entrances collapsed when the tide reached them and formed a stopper which prevented water from intruding into the nest. In this way, the galleries remained dry during high tide. The ants showed a clear swimming or "walking on the surface" behaviour when they returned to the nest just before the entrance collapsed and during ebb. The tolerance of the ants to submergence was tested in the laboratory, with 50% mortality after 11 hours submergence in seawater at 23 °C, and only 3.5 hours in water at 33 °C. Therefore, the nesting behaviour with trapped air in the galleries is necessary for survival in these environments.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s000400050026
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  • 16
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    A comparison of ant assemblages (Hymenoptera, Formicidae) on serpentine and non-serpentine soils in northern California (1997)
    Springer
    Insectes sociaux 44 (1997), S. 23-33 
    Details
    ISSN: 1420-9098
    Keywords: Key words: Diversity, chaparral, Formicidae, inventory methods, serpentine.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary: In northern California, ant assemblages in 8 sites in serpentine chaparral habitat were compared with those occurring in 8 chaparral sites on adjacent non-serpentine soils. A total of 27 species of ants was found: 22 species were collected in non-serpentine chaparral and 20 species in serpentine chaparral. Seven species were collected exclusively in non-serpentine, and 5 species were found only in serpentine habitats. A Formica species, conspecific with or closely related to F. xerophila, was found only in serpentine chaparral. Subsequent collections suggest that in northern California, this species is confined to serpentine outcrops. Two other species significantly differed in frequency of occurrence in each habit:Camponotus hyatti, C. cf. vicinus. Five species showed marginal significant differences in their relative abundance between habitats:Camponotus hyatti, C. cf. vicinus, Formica moki, Prenolepis imparis, Leptothorax nevadensis, Stenamma diecki.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s000400050027
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  • 17
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    Colony foraging in different species of stingless bees (Apidae, Meliponinae) and the regulation of individual nectar foraging (1997)
    Springer
    Insectes sociaux 44 (1997), S. 35-47 
    Details
    ISSN: 1420-9098
    Keywords: Key words: Foraging activity, Meliponinae, Melipona favosa, M. fasciata, M. beecheii, Tetragonisca angustula.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary: For Melipona fasciata, M. beecheii, M. favosa and Tetragonisca angustula we found distinct intergeneric differences in foraging activity patterns. The Melipona species had a longer daily foraging activity period than T. angustula. Pollen foraging patterns of the Melipona species were different from that of T. angustula: Melipona collect pollen earlier in the day. In an experimental habitat without competitors, Melipona favosa did not collect pollen very early in the day. ¶Individually marked returning foragers demonstrated in the course of the day distinct differences in nature and frequency of interactions with nest mates. Individual foraging flight frequency was lower and the intranidal transfer of nectar was delayed when syrup of a lower concentration was offered. ¶The regulation of daily foraging activity patterns and the nectar foraging behaviour of individual worker bees are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s000400050028
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  • 18
    Electronic Resource
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    Suppression of plant growth on the mounds of the termite Coptotermes lacteus Froggatt (Isoptera, Rhinotermitidae) (1999)
    Springer
    Insectes sociaux 46 (1999), S. 366-371 
    Details
    ISSN: 1420-9098
    Keywords: Key words: Termites, nest construction, plant growth suppression, plant abundance.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary: Termites invest considerable time and energy constructing elaborate mounds out of clay, sand, silt, excreta and saliva, which they defend vigorously against predators and parasites. Termite mounds are fertile and potentially attractive resources for plants, which may threaten the stability of the mound. Field surveys at Boola Boola Forest in SE Australia revealed significantly higher abundance and diversity of vascular plants growing on uninhabited than inhabited mounds of the termite Coptotermes lacteus. These data reveal that the presence of termites affects the establishment and growth of vegetation. Germination experiments indicate that plant growth suppression is not chemically mediated but rather is due to the impenetrable nature of the mound surface. Analyses of soil types suggests that termite workers may choose particular clay minerals for mound construction, which enhances surface impenetrability and thus increases the engineered integrity of the mound.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s000400050158
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  • 19
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    Reproductive schedule and factors affecting soldier production in the eusocial bamboo aphid Pseudoregma bambucicola (Homoptera, Aphididae) (1999)
    Springer
    Insectes sociaux 46 (1999), S. 378-386 
    Details
    ISSN: 1420-9098
    Keywords: Key words: Eusocial aphids, Pseudoregma bambucicola, resource allocation, soldier investment, reproductive schedule.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary: The reproductive characteristics of the soldier-producing aphid Pseudoregma bambucicola were studied in Kagoshima, Southern Japan, to know the factors affecting soldier production of eusocial aphids. The soldier proportion in aphid colonies was highest from October to November. In some large colonies, soldiers were observed in all seasons except in July when colony size was relatively small. Multiple regression analysis showed that the colony size was a principal factor affecting soldier proportion throughout a year. Other social or environmental factors such as aphid composition, host plant conditions and predator abundance were not always significant. Rearing experiments revealed that large colonies (≥1,000 individuals) produced soldiers in almost all seasons while small colonies (〈1,000) never produced any soldiers. The caste-production schedule of adult females was examined in the field. When solitary females produced both castes, they usually produced normal nymphs first and then soldiers. Females from large colonies tended to produce more soldiers in the earlier period of their lifetime, whereas females from newly established small colonies produced no or only a few soldiers at later times. The average number of soldiers and normal nymphs produced consecutively by a single female was 〉10 and 〉20, respectively. Because they have a small number of ovarioles (〈15 on average), females should alter caste production within the same ovarioles according to changes in environmental conditions. Artificial removal or introduction of predators and reduction of colony size did not affect soldier production over two successive generations, revealing maternal effects on soldier production. Females cannot shift caste production quickly in response to changes in predator abundance and colony size. This is probably due to early developmental determination of castes within the mother's body.
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    URL: http://dx.doi.org/10.1007/s000400050160
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    Field survey of a monogynous leptothoracine ant (Hymenoptera, Formicidae) evidence of seasonal polydomy ? (1997)
    Springer
    Insectes sociaux 44 (1997), S. 75-83 
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    ISSN: 1420-9098
    Keywords: Key words: Leptothorax, colony size, demography, polydomy, Formicidae.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary: 484 nests of Leptothorax tuberointerruptus were collected from a coastal limestone grassland community in Dorset, England, over a 16 month period from February 1992 to May 1993. Behavioural observations and dissections of females strongly suggested that the nests were obligately monogynous. Electrophoretic data also suggested that within most nests all the workers shared the same mother and father. Counts of nest contents revealed temporary but dramatic drops in both worker and queen numbers per nest in May—June 1992. Seasonal polydomy is postulated to be the cause of this variation. Such dramatic variation highlights the importance of sampling over as much space and time as possible if premature conclusions about colony demography are to be avoided.
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    URL: http://dx.doi.org/10.1007/s000400050031
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    Explosive food recruitment as a competitive strategy in the ant Myrmica sabuleti(Hymenoptera, Formicidae) (1997)
    Springer
    Insectes sociaux 44 (1997), S. 59-73 
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    ISSN: 1420-9098
    Keywords: Key words: Ants, foraging, interspecific competition, Myrmica sabuleti, Formica fusca.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary: Myrmica sabuleti forms mature colonies of about one thousand workers and a few queens. Although living in dry and sunny biotopes, this species avoids foraging during the warmer hours of the day which correspond to the period of the maximum foraging activity of two sympatric species, Formica fusca and F. cunicularia. M. sabuleti is the most frequently observed species on the extrafloral nectaries of Vicia sativa, even during the warmer hours of the day, whereas F. fusca is the most frequent species during those hours at tubes of 1M sucrose solutions placed on the ground. In spite of this temporal segregation, the foraging activity of M. sabuleti and F. fusca overlaps two times a day (10:00‐11:00 am and 5:00‐8:00 pm). Newly discovered large food sources are exploited by M. sabuleti through an explosively increasing recruitment, whereas workers of F. fusca forage mainly individually. Interference between M. sabuleti and F. fusca was studied when offering sucrose solutions, large dead insects unretrievable by individual foragers of either species (cockroaches), medium-sized insects retrievable by single foragers of F. fusca but not by single M. sabuleti(larvae of Calliphora erythrocephala) and small insects (Drosophila) retrievable by individual foragers of both species. Owing to its rapid recruitment, M. sabuleti is able to displace F. fusca from sucrose solution and large dead prey during the overlaping of the activity cycles of both species. When medium-sized corpses are offered, the issue depends on the speed of the events. F. fusca is able to take the prey away only if it discovers it before M. sabuleti has recruited nestmates. Small dead prey do not lead to interference, but is taken by the first worker that finds it.
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    URL: http://dx.doi.org/10.1007/s000400050023
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    Nest-founding behavior induced in the first descendants ofPolistes dominulus Christ (Hymenoptera: Vespidae) colonies (1995)
    Springer
    Insectes sociaux 42 (1995), S. 385-396 
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    ISSN: 1420-9098
    Keywords: Polistes wasps ; nest founding ; workers ; behavioral flexibility ; hibernation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary First descendants' founding ability was tested inP. dominulus colonies by experimentally removing the original nests and queens 21–24 days after the first emergence. Foundation tests were carried out after three different periods had elapsed after the removal and the results were analyzed with regards to the effects of participation in social tasks, duration of stay within the colony and seasonal factors. 1.Immediately after the removal, the foundations that occurred were performed almost entirely by workers, regardless of the duration of their stay within the colony. The number of foundations depended on the season in which the females had emerged. 2.Two months and four months after the removal, foundations were made by only a small number of females (workers and non-workers). These females, which were therefore able to found a nest the year they were born, were mostly among the very first-born individuals in the colonies. 3.The following year after hibernation: females (workers and non-workers) which had stayed for only a short time within the colony (1–15 days) had the highest survival rates. The foundation rates among the surviving females depended only on seasonal factors, since the foundation rates were higher among the non-workers which had emerged later in the season. The results throw some light on the first descendants' nest-founding potential in colonies developing under natural conditions, where many workers in fact stay for only a short time at the nest.
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    URL: http://dx.doi.org/10.1007/BF01242167
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    Foraging organization of the open-air processional lichenfeeding termite Hospitalitermes (Isoptera, Termitidae) in Borneo (1998)
    Springer
    Insectes sociaux 45 (1998), S. 17-32 
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    ISSN: 1420-9098
    Keywords: Key words: Caste-ratio dynamics, division of labor, foraging frequency, open-air foraging, social behavior.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary: The temporal dynamics and social interaction in the foraging activities of the open-air processional termite Hospitalitermes (Termitidae, Nasutitermitinae) were studied in Borneo, Southeast Asia. H. medioflavus and H. sp. A tended to forage from evening to the next morning. On average foraging activity occurred every 3.2 days. Some synchronization of foraging events among colonies was observed, which appeared to be caused by rainfall levels.¶ Temporal dynamics during foraging activity was observed in detail using a photographic method for two species; H. medioflavus and H. rufus. Roughly 300,000 to 500,000 individuals participated in a single foraging event in both species. The soldier ratio was highest at the beginning and the end of the activity. Temporal patterns of behavior were different between soldier, major worker, medium worker and minor worker during foraging. The patterns of behavior are consistent with their tasks in the foraging activity. Soldiers lead the foraging column and protect it, major workers act as food carriers in the earlier stage while medium workers become the dominant food ball carriers in the later stage, and minor workers play the role of gnawers. Therefore, caste composition changes during foraging activity. Similar behavioral tendencies were recognized in both species. Measurement of workers' body weights revealed that workers not only carry balls of food from foraging sites but also feed directly at the foraging sites.
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    Nesting site selection by wasps in the Guianese rain forest (1998)
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    Insectes sociaux 45 (1998), S. 33-41 
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    ISSN: 1420-9098
    Keywords: Key words: Wasps, nesting sites, palm trees, Astrocaryum sciophilum, French Guiana.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary: In the edge of the rain forests in French Guiana, the large leaves of young Astrocaryum sciophilum, a palm tree with long thin spines (up to 9 cm) along their central vein, shelter significantly more mason as well as social wasps' nests, than leaves of other plants. Other such plants include older conspecific individuals with spines, but compound leaves, and young Bactris simplifrons, a palm tree with similar leaves but devoid of spines. The choice of these leaves is due to the association of two factors: (1) these large leaves with a concave underside offer good protection against inclement weather, and (2) the spines on which the wasps' nests are anchored serve as "acquired pedicels", offering protection against ant predation. As a consequence, the wasps' nests are found under these leaves in both inter- and intraspecific clusters.
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    Intra- and interspecific agonism in Reticulitermes flavipes (Kollar) and R. virginicus (Banks) and effects of arena and group size in laboratory assays (1998)
    Springer
    Insectes sociaux 45 (1998), S. 43-49 
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    ISSN: 1420-9098
    Keywords: Key words: Isoptera, Rhinotermitidae, Reticulitermes, agonistic behavior.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary: Displays of intraspecific and interspecific overt agonistic behavior between colonies of Reticulitermes flavipes (Kollar) and colonies of Reticulitermes virginicus (Banks) were observed in laboratory assays. All possible combinations of arena sizes (1.3, 3.5, 6.0, and 9.0-cm) and group sizes (1, 2, 5 and 10 workers per arena) were assessed for effects on interspecific and intraspecific agonism. Agonistic behavior was scored positive in arenas if half or less of the starting number of termites was alive after 24h. Thirty-six percent of arenas with interspecific pairings were agonistic in all combinations tested while 4.5 % of arenas with intraspecific combinations showed aggression (N = 544 and N = 288, respectively). Two interspecific pairings provided scores that were not statistically different from intraspecific combinations. These assays indicate that evidence of overt agonism between worker termites from these two Rhinotermitid species is not a reliable indicator to differentiate species. Encounters in the two larger arena sizes resulted in significantly more agonism than the two smaller arena sizes. Group size had little apparent effect on the frequency of positive agonistic interactions. Possible reasons for the variable overt agonism scores are discussed.
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    Ecological factors promoting the evolution of colony defense in aphids: computer simulations (1996)
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    Insectes sociaux 43 (1996), S. 1-15 
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    ISSN: 1420-9098
    Keywords: Colony defense ; sterile soldiers ; aphids ; galls ; simulation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Colony defense has been reported in a limited number of species of aphids. This paper examines which life-historical traits have promoted the evolution of colony defense using two kinds of deterministic simulation models. These models postulate that first-instar larvae can counterattack predators and that the duration of this instar stage is a variable, subject to selection. Prolonging the first-instar span increases the proportion of defenders in the colony, while it results in a delay in reproduction. By calculating the optimal first-instar span, the optimal defensive effort of a colony under various ecological conditions could be estimated. Simulations based on the general model, which regards the number of adults maturing in a period as performance, predicted that a lower birthrate leads to a longer first-instar span (larger investment in defense). This condition also allowed the evolution of dimorphism in the first-instar span, which may ultimately result in the appearance of soldiers. Where birthrate declines with time, the first-instar span was predicted to be prolonged in later stages. Colony duration had little influence on the optimal first-instar span if the season is long enough to repeat generations. The galling-aphid model that assumes a fixed number of generations predicted that a longer duration of colonies leads to a longer first-instar span, but that birthrate has little influence on the optimal first-instar span. A tendency in defense reported in pemphigid aphids was consistent with the prediction from the galling-aphid model.
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    URL: http://dx.doi.org/10.1007/BF01253951
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    The effects of temperature on the architecture and distribution of Macrotermes bellicosus (Isoptera, Macrotermitinae) mounds in different habitats of a West African Guinea savanna (1998)
    Springer
    Insectes sociaux 45 (1998), S. 51-65 
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    ISSN: 1420-9098
    Keywords: Key words: Gallery forest, Ivory Coast, savanna, termites, thermoregulation.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary: We determined density and distribution of the mounds of the fungus-cultivating termite Macrotermes bellicosus (Smeathman) in two habitats (shrub savanna and gallery forest) of the Comoé National Park (Ivory Coast, West Africa). We measured height, basal width, and interior and exterior temperatures of mounds in both habitats, and established a new method to measure the surface area of mounds.¶ In the shrub savanna, M. bellicosus mounds reached high densities (up to 22.7 live mounds/ha), whereas in the gallery forest mounds could only be found in open stands and at comparatively low densities (up to 6.5 live mounds/ha).¶ Ambient temperature had an important influence on the architecture of the mounds. Mounds in the warmer, but thermally more fluctuating shrub savanna were more structured with many ridges and turrets than the dome-like, compact mounds in the cooler, more equable gallery forest. The surface complexity was quantified as the ratio of surface (= rsf), which is the quotient of the real surface to the minimal possible surface of an ideal cone of the same height and basal width as the measured mound. By manipulating ambient temperatures, we were able to demonstrate causal relationships between temperature and mound shape. In the gallery forest, where shade was reduced surface complexity increased on mounds.¶Despite their different architecture in the gallery forest, the M. bellicosus colonies could not completely compensate for the cooler environment and had a lower than optimal nest temperature. We speculate that this might be caused by the need for a sufficient surface for gas exchange. The gallery forest is a suboptimal habitat for M. bellicosus, because of lower than optimal nest temperatures. This might limit M. bellicosus to open stands in the gallery forest and may explain its surprisingly low abundance in this habitat.
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    Size-dimorphism in the queens of the North American ant Leptothorax rugatulus (Emery) (1998)
    Springer
    Insectes sociaux 45 (1998), S. 67-77 
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    ISSN: 1420-9098
    Keywords: Key words: Size polymorphism, microgynes, reproductive strategies, dispersal.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary: With recent findings of an unexpected variability in the reproductive behaviour of ant sexuals, their morphology has become an area of major evolutionary interest (Heinze and Tsuji, 1995). Here we report on the occurrence of two queen morphs in Leptothorax rugatulus (Hym., Formicidae): Microgynes (small queens), exceeding worker-size only marginally, and macrogynes, which are, typically for the subgenus Myrafant, about twice as big as their workers. The frequency distribution of queen-size is clearly bimodal, in contrast to worker- and male-size. The average size of queens is highly correlated with the size of daughters in field-collected colonies, whereas within colonies no correlation between the average queen-size and the size of workers or males exists. This gives additional support that size-dimorphism is due to a specific, transmissible size reduction of the microgynes which could be based on genetics, the environment or both. This reduction is quasi-isometric, with a slightly smaller thorax-to-head ratio in microgynes, and scanning electron microscopy does not reveal any significant degeneration of the pterothorax, ocelli or number of ommatidia. The frequency of microgynes at different sample sites is highly variable, correlating well with the prevailing social structure in the respective subpopulations. Indeed, the majority of macrogynes is found in monogynous colonies, while microgynes abound in polygynous ones, which is strong evidence for an alternative dispersal tactic. However, the expected correlation to altitude or latitude was not found and further investigations are needed to reveal proximate and ultimate causes of this prevalent polymorphism between two types of female ant reproductives.
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    Chemical communication during foraging in the harvesting ant Messor capitatus (Hymenoptera, Formicidae) (1998)
    Springer
    Insectes sociaux 45 (1998), S. 85-96 
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    ISSN: 1420-9098
    Keywords: Key words: Chemical communication, Dufour's gland, recruitment, trail following, Messor capitatus.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary: Some aspects of the chemical communication system employed by the harvesting ant Messor capitatus during foraging were investigated in the laboratory. After locating a conspicuous food item the scouts return home dragging their gaster on the ground. Once inside the nest they run among nestmates and perform an excited motor display. Soon after, groups of workers rush out and move towards the food. Bioassays of different gland extracts showed that nestmates are activated and induced to leave the nest by substances from Dufour's gland. This gland was also found to be the source of the orientation-recruitment trails by which foragers reach newly discovered food sources. The bioassays showed that poison gland extracts are also active in inducing trail following. However, this response was accompanied by typical aggressive reactions by tested ants, suggesting that the poison gland is involved in alarm communication and recruitment towards a source of danger rather than in foraging activities. Some features of the Dufour's gland trail (such as its durability and lack of colony-specificity) are discussed with regard to the ecological requirements of this species.
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    URL: http://dx.doi.org/10.1007/s000400050071
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    Intercastes, intermorphs, and ergatoid queens: who is who in ant reproduction? (1998)
    Springer
    Insectes sociaux 45 (1998), S. 113-124 
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    ISSN: 1420-9098
    Keywords: Key words: Leptothorax, Formicoxenini, ergatoid queens, intermorphic queens, intercastes, morphology.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary: The terminology for ant females which are morphologically intermediate between “normal”, originally winged queens and workers teems with ill-defined terms, such as “ergatogyne”, “apterogyne”, or “gynaecoid worker”. The terminology proposed by Peeters (1991a) gets rid of most of these terms but fails to distinguish between sporadically occurring “intercastes”, reared due to “mistakes” in caste differentiation, and “intermorphic queens”, which are the ordinary female reproductives in many colonies of formicoxenine ants. A detailed examination of development, morphology, and occurrence of the latter suggests that intermorphic queens are more similar to ergatoid queens (sensu Peeters, 1991a) than to “intercastes”, and should not be comprised under the latter term.
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    Demography and relatedness in multiple-foundress nests of the social sweat bee, Halictus ligatus (1998)
    Springer
    Insectes sociaux 45 (1998), S. 97-109 
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    ISSN: 1420-9098
    Keywords: Key words: Halictidae, pleometrosis, social evolution.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary: Female sweat bees in the species Halictus ligatus exhibit a wide range of reproductive roles, ranging from typically foundress or queen-like to typically worker-like. Nests are founded in spring and most are haplometrotic, that is, founded by a single foundress. A few (up to 12 %) are pleometrotic, founded by 2-6 foundresses. Variation in the proportion of multifoundress nests from year to year and from place to place suggests an adaptive basis for pleometrosis. We studied the demographic and social characteristics of 23 pleometrotic nests in an aggregation of 250-300 nests near Victoria, Ontario, in 1984, 1990, and 1991. In pleometrotic associations, dominant foundresses behaved in a manner typical of mid-summer, haplometrotic queens, while subordinates behaved like mid-summer workers. Dominant foundresses tended to be larger than subordinates. Pleometrotic nests were significantly more likely than haplometrotic nests to produce brood, and they also produced more workers. However, this early advantage did not result in the production of more reproductive brood per nest, nor did pleometrotic foundresses experience higher productivity per foundress than did haplometrotic foundresses. Relatively low relatedness among various categories of brood implied that subordinate foundresses were not closely related to dominants. We suggest that pleometrosis most likely results from accidental encounters between spring foundresses as they leave their hibernacula. Once formed, such associations confer a survival advantage on the nest as a whole, but do not result in greater reproductive brood productivity.
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    Colonial life versus solitary life in Cyrtophora citricola (Araneae, Araneidae) (1998)
    Springer
    Insectes sociaux 45 (1998), S. 125-134 
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    ISSN: 1420-9098
    Keywords: Key words: Life history, kleptoparasitism, interspecific relationships, sociality, spiders.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary: Among spiders, some species could be qualified as colonial. Individuals may live alone or in colonies where each spider exploits its own capture web in a communal network. We compared solitary with colonial life in Cyrtophora female populations from South-East Sicily in 1992 and 1993. We used 6 parameters to describe and compare the populations: spider size, web size, egg production, prey captured, presence of kleptoparasites and their size.¶ Spiders living in colonies did not differ in size from solitary spiders.¶ The webs of colonial spiders were smaller than those of solitary spiders.¶ The number of prey captured and their size did not differ between the two types of spiders.¶ Solitary spiders produced more eggs than colonial individuals.¶ Kleptoparasite spiders Argyrodes gibbosus were more numerous in the webs of solitary spiders than in the webs of colonial spiders and there were more solitary webs infested by kleptoparasites in 1992. The kleptoparasites were larger in colonial webs than in solitary ones. Another species of spider, Holocnemus pulchei, spun its own web in the network of the web of Cyrtophora. The number of Holocnemus per web did not differ between solitary and colonial Cyrtophora.¶ Results are discussed by referring to what it is known in other temporarily social spiders.
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    Latency time and absence of group effect (1998)
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    Insectes sociaux 45 (1998), S. 191-195 
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    ISSN: 1420-9098
    Keywords: Key words: Group effect, latency time, fungus-growing termites, building behavior, bees, aggressiveness.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary: We suggest that group effect need not be invoked to explain the differences in latency times exhibited by groups of different sizes in the initiation of building in the termite Macrotermes subhyalinus (Rambur). A simple, alternative, model is presented, that is fully consistent with experimental data.
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    Queen and colony odour in the multiple nest ant species, Cataglyphis iberica (Hymenoptera, Formicidae) (1998)
    Springer
    Insectes sociaux 45 (1998), S. 301-313 
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    ISSN: 1420-9098
    Keywords: Key words:Cataglyphis, worker odour, queen odour, Formicidae, polydomy.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary: We investigated the queen's effect on the cuticular hydrocarbon profile of workers in the monogynous and polydomous species Cataglyphis iberica. Within each of the three colonies tested, workers were separated for three months in queenright and queenless groups. After regrouping, nestmate recognition remained unchanged but the duration of antennal interactions between workers previously separated increased relative to controls. Separated groups presented slightly divergent cuticular hydrocarbon profiles which may induce the longer antennations. A quantitative analysis of major cuticular hydrocarbons showed that the total amount per unit of cuticular surface area remains similar between the two castes; but queens had higher quantities of n-alkanes than workers. The lack of a queen did not affect the workers' cuticular hydrocarbon profile in queenless groups. Indeed, the profile of queenless workers remained significantly different from the queen profile as did that of queenright workers. These results show that queens are not at the origin of the hydrocarbons' colonial profile. Two recognition processes seem to coexist within C.iberica colonies: nestmate discrimination based on the colonial odour which includes all nestmate workers, and a queen caste-specific odour. In a polydomous species such as C.iberica, the queen does not seem to contribute more than any other nestmate to the colonial odour, which probably derives from worker cues, confirming the existence of a "Gestalt" colonial odour.
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    The number of castes in ants, where major is smaller than minor and queens wear the shield of the soldiers (1998)
    Springer
    Insectes sociaux 45 (1998), S. 315-333 
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    ISSN: 1420-9098
    Keywords: Key words: Soldier, caste, evolution, ants.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary: The traditional hypothesis that ant soldiers originate from large size workers is rejected in favour of their direct origin from gynes. This conclusion is supported by the first report of soldiers smaller than workers, by an intercaste morphometric comparative analysis by means of D'Arcy Thompson's transformation grids and by phylogenetic studies on Cephalotes showing that the cephalic shield appeared ancestrally among soldiers and only later among gynes. The same conclusion flows from facts already known but hitherto misunderstood and stressed in this paper such as: 1) there are species of Cephalotes with soldiers with incomplete cephalic shield and no gyne shield and other species with complete soldier shield but only incomplete gyne shield; 2) the phragmotic behaviour is exercised by workers and soldiers and not by gynes but its morphological correlate, i.e., the shield-shaped head, occurs among soldiers and gynes and not in workers. These observations prove that the selection pressure for the shield morphology acts on workers and soldiers and not on gynes but its morphological correlate actually appears first in soldiers, later in gynes and never in workers. These data sharply contrast with a worker origin of soldiers and are perfectly consistent with the hypothesis of a separate origin of soldiers directly from gynes.
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    Evolution of sociality in the allodapine bees: a review of sex allocation, ecology and evolution (1998)
    Springer
    Insectes sociaux 45 (1998), S. 349-368 
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    ISSN: 1420-9098
    Keywords: Key words: Social evolution, sex allocation, kin selection, comparative studies, Exoneura, Apidae.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary: Comparative studies provide one of the most powerful means of assessing the relative roles of selective agents underlying social evolution in insects. Because of the wide variation in social organisation, sex allocation and ecological traits within and between species of allodapine bees, this group provides a wealth of material for such comparative work. Recent studies on Australian allodapine bees are reviewed here and their consequences for understanding social evolution are discussed. Studies to date suggest the following trends: (i) benefits of group living appear to be linked to preventing brood failure rather than to increased brood rearing efficiency; (ii) female-biased sex allocation, when it occurs, is linked to benefits of group living and kinship among nestmates, and is probably mediated via local fitness enhancement; (iii) female-biased sex allocation patterns do not usually coincide with opportunities for sib-rearing and are therefore unlikely to facilitate eusociality; (iv) relatedness within colonies is usually high, but in some species females will nest with unrelated females if kin are not available; and (v) phylogenetic studies suggest that opportunities for sib-rearing, arising from brood development patterns and colony phenology, are plesiomorphic for the exoneurine group, but in at least one phylogenetically distal clade, Exoneura sensu stricto, the evolution of large group size and social complexity coincides with the loss or reduction of opportunities for sib-rearing. Assured fitness return models may be applicable to weakly social allodapine species, but do not predict patterns of eusociality. Instead, Australian studies suggest that the evolution of large group size and marked reproductive skew is linked with the need to defend against enemies at the nest, rather than high levels of relatedness, female biased sex allocation or opportunities to rear siblings.
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    Long-duration feedings and caste differentiation in Bombus terrestris larvae (1999)
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    Insectes sociaux 46 (1999), S. 315-322 
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    ISSN: 1420-9098
    Keywords: Key words:Bombus terrestris, bumble bee, larval feeding, caste differentiation.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary: The duration of feedings received by Bombus terrestris larvae was studied using video-recordings. In the last days of development all larvae received feedings mainly of long duration. Worker larvae of the third brood received significantly longer feedings than worker larvae reared in the other broods. Throughout the development queen larvae and worker larvae received feedings of similar duration. Male larvae received shorter feedings than both kinds of female larvae. Therefore, the duration of feedings seems to be associated to the sex and stage of development of the larvae.¶The causes of the long-duration feedings seem not to be related to the amount of food provided, workers' age and size, to the workers' abdominal contraction or to the amount of pollen in the larval food. Perhaps the feeding duration is caused by the viscosity of the food, which is a consequence of the presence of pollen grains, sugar and glandular material. Although the precise amount of pollen was not measured, the differences in colour showed clearly that the larval food samples contained variable quantities of pollen grains. Some of the samples did not contain any pollen at all.¶It is suggested that the duration of feedings may be related (among other factors) to the presence of glandular material (proteins and enzymes) which is added to the larval food. This could be especially important for queen larvae in the last phase of their development. Because they have a long development and are fed with a high frequency they might receive large amounts of these substances. This could help them to grow more efficiently using a relatively smaller amount of pollen than expected.
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    Behavioural development and abdomen inflation of gynes and newly mated queens of Melipona beecheii (Apidae, Meliponinae) (1999)
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    Insectes sociaux 46 (1999), S. 361-365 
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    ISSN: 1420-9098
    Keywords: Key words: Pre-mating behaviour, gyne, abdomen enlargement, Melipona beecheii, stingless bee.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary: The behaviour of gynes of Melipona beecheii in queen-deprived colonies was studied. The period after emergence until acceptance is characterized by agonistic behaviour of workers towards the gynes. The gynes escaped from this worker aggression by hiding in the periphery of the nest, by performing rapid turn-arounds once grabbed by a worker, and "feigning death". Between acceptance and nuptial flight, gynes spent most of their time in pushing, hiding, and antennal contact with workers, and self-grooming or food solicitation. After the nuptial flight the queen's behavioural repertoire shifted to less pushing and food solicitation, to an increase in standing, tapping and antennal contact.¶Accepted gynes had a significantly more prolonged abdomen inflation than gynes that were eliminated.¶An hypothesis is presented to explain how abdomen enlargement and behavioural development influences the acceptance of gynes and the establishment of a dominance relation with workers under queenless conditions.
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    Gegenläufiges Verhalten des Verlaufes von Druck und Temperatur in der Unteren Troposphäre (1948)
    Springer
    Pure and applied geophysics 11 (1948), S. 8-18 
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    ISSN: 1420-9136
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Description / Table of Contents: Summary The vertical temperature gradient for selectet stations shows an annual variation which cannot be explained by the diurnal variation of temperature. The annual variation of temperature at fixed levels in the lower layers of atmosphere shows a trend opposite to these variations at fixed elevations in the middle layers. This fact indicates that the troposphere cannot be regarded as a layer of uniform structure. The interdiurnal variations of pressure and temperature for the individual levels and their opposite trend compel us to postulate within the troposphere a lower layer as has been observed before in various occasions and then called the layer of disturbation. It is possible to generalize these observations and to conceive of the lower layer as a planetary phenomenon and as the ground layer of the atmosphere.
    Abstract: Riassunto Il gradiente termico verticale presenta una variazione annuale che non può venir spiegata con la variazione diurna della temperatura. La variazione annuale della temperatura a livelli determinati nei bassi strati dell'atmosfera rivela un andamento opposto a quello che si riscontra negli strati centrali della troposfera. I due fatti dimostrano che la tropofera non può venir considerata come uno strato avente struttura uniforme. Le variazioni interdiurne della pressione e della temperatura nei singoli strati verticali ed il loro comportamento inverso conducono all'esistenza di uno strato inferiore in seno alla troposfera, già prima occasionalmente osservato e definito strato di perturbazione. Simili osservazioni sono atte a venir generalizzate in quanto questo strato inferiore è concepibile come fenomeno planetärio e come strato base dell'atmosfera.
    Notes: Zusammenfassung Der vertkkale Temperaturgradient hat bei ausgewahlten Stationen einen jährlichen Gang, der nicht durch den täglichen Temperaturgang erklärbar ist. Die jährliche Temperaturschwankung in Abhängigkeit von der Höhe zeigt ein gegenläufiges Verhalten zwischen den unteren und den mittleren Schichten der Troposphäre. Beide Erscheinungen weisen darauthin, dass man die Troposphäre nicht als eine Schicht von einheitlichem Aufbau ansehen kann. Die interdiurnen Anderungen von Druck und Temperatur in den einzelnen Höhenschichten und ihr gegenläufiges Verhalten zwingen dazu eine untere Schicht in der Troposphäre auszusondern, die scho gelegentlich früher beobachtet und dann als Störungsschicht bezeichnet wurde. Diese Beobachtungen sind aber einer Verallgemeinerung fähig, indem diese untere Schicht als planetarische Erscheinung aufzufassen und als Grundschicht der Atmosphäre zu kennzeichnen ist.
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    Le climat change-t-il? (1948)
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    Pure and applied geophysics 12 (1948), S. 1-3 
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    Topics: Geosciences , Physics
    Description / Table of Contents: Summary The exceptional thermic conditions of the winter 1946–47 and the summer 1947 are discussed. These conditions do not mean a change of the climate of Western Europe. They concide with a period of intensive solar activity. Generally narrow connexion are present between periods of large (small) variability of the climate and large (small) solar activity.
    Notes: Résumé Les conditions thermiques exceptionelles de l'hiver 1946–47 et de l'été 1947 sont discutées en déduisant que cela ne signifie pas un changement de climat pour l'Europe occidentale: en effet, il s'agit seulement d'une coincidence avec une période d'intense activité solaire, y ayant en général une correspondance entre les époques de grande (ou petite) variabilité du climat et les périodes de forte (ou faible) activité solaire.
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    Die Ausbreitung hochfrequenter Hertzscher Felder in Kalilagerstätten (1948)
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    Pure and applied geophysics 12 (1948), S. 23-52 
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    ISSN: 1420-9136
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Description / Table of Contents: Summary The purpose of the experiments described in this paper was to investigate the conditions of propagation of a transmitter situated below the surface of the ground. This problem is of interest to both radio engineers and geophysicists. By determination of the extinction and reflection areas of electrical discontinuity may be located. The experiments were carried out in German potassic salt mines. Rocks of potassic salts are known as very bad conductors. Therefore the extinction is but very little. In this area ranges up to 14 kilometres were reached. This is the greatest range obtained up to now under the surface of the ground. The investigations were carried out with different wave lengths from 10 up to 2000 metres. The influence of geological discontinuities, alkaline deposits and disturbed areas was always very great. The author mentions that the above ranges could certainly still be considerably increased by application of all technical means available at present.
    Notes: Zusammenfassung 1) Die Versuche fanden in den Gruben Hannovers, des Werragebietes und des Südharzes statt. 2) Die Untersuchungen erstreckten sich über das ganze praktisch in Betracht kommende Wellenband, angefangen von den Meterwellen bis in den 1000 Meter-Bereich. 3) Im Zuge der Untersuchungen konnten die bisher grössten, unter Tag überhaupt erzielten Reichweiten erreicht werden. Die grösste Reichweite wurde zwischen zwei Hannoverischen Gruben erzielt und betrug bei 14 Kilometer. 4) Frequenz und geologische Faktoren sind stets von Einfluss. 5) Die Versuche zeigen, dass unter Kalilagerstätten Funkmutungsverfahren nach dem Reflexions- und Refraktionsprinzip für grössere Aufschlussteufen möglich sind. 6) Die Versuche haben alle Voraussetzungen des Grubenfunks so weit geklärt, dass dessen praktischer Einführung nichts im Wege steht.
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    La profondita' del foco dedotta dall'angolo d'emergenza delle onde sismiche (1948)
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    Pure and applied geophysics 12 (1948), S. 108-112 
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    ISSN: 1420-9136
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
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    Giovanni Agamennone nel suo 90° compleanno (1948)
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    Pure and applied geophysics 12 (1948), S. 105-107 
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    Some long period variations of microseismic activity (1948)
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    Pure and applied geophysics 12 (1948), S. 121-126 
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    ISSN: 1420-9136
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    Topics: Geosciences , Physics
    Description / Table of Contents: Zusammenfassung Die in Uppsala registrierte Bodenunruhe ist für die Zeit 1907–1947 betreffs langperiodischen Schwankungen untersucht worden. Eine 11-jährige Variation wird festgestellt und es gibt weiter Anzeichnungen einer Variation von 28 Monaten. Die 11-jährige Variation ist seit 1923 zur Sonnenflecken-frequenz negativ korreliert und ist durch entsprechende meridionale Verschiebungen der am meisten betretenen Zyklonenbahnen, erklärt.
    Abstract: Riassunto L'agitazione microsismica registrata a Uppsala nel quarantennio 1907–1947 venne esaminata in vista di determinare le oscillazioni di lungo periodo. Si è accertata una oscillazione undecennale, trovandosi altresi indizi per una oscillazione di 28 mesi. Dal 1923 l'oscillazione undecennale manifesta una correlazione negativa con la frequenza delle macchie solari e viene spiegata con i corrispondenti spostamenti meridionali delle rotte cicloniche dominanti.
    Notes: Summary The microseisms recorded at Uppsala have been studied for the time 1907–1947 with regard to long period variations. There is clear evidence of an 11 year variation and slight indications of a 28 month variation. The 11 year variation is from 1923 negatively correlated to the sunspot frequency and is explained by corresponding meridional displacements of the dominant cyclonic tracks.
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    Notiziario (1948)
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    Pure and applied geophysics 12 (1948), S. 168-169 
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    Tremblements de terre et anomalies magnétiques (1948)
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    Pure and applied geophysics 12 (1948), S. 134-144 
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    ISSN: 1420-9136
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Description / Table of Contents: Summary It was yet often noted that the earth's magnetic field has been steadily modified on the result of seismic earth movements. The author cites many recent examples of magnetic anomalies measured in Japan after major earthquakes (Kato). The «Bassin de Paris»'s magnetic anomaly is modified during a certain time in a possible connection with magmatic removals and with some seismic activity. The earthquake of June 11 th., 1938 in Belgium shows some very interesting connections with the belgian magnetic anomaly. Suggestive relationships are noted between changes in the earth's secular magnetic field and areas of seismicity (Omer). The author thinks that the earthquakes and the deformations of the earth's magnetic field are more or less closely connected one with another, and it may perhaps be that the atomic energy (chain reactions) may explain some orogenic earthquakes and their aftershocks.
    Notes: Résumé On a déjà souvent signalé que le champ magné ique terrestre s'est trouvé modifié de façon durable à la suile de mouvements séismiques. L'auteur rappelle plusieurs exemples récents d'anomalies magnétiques mesurées au Japon à la suite d'importants séismes (Kato). L'anomalie magnélique duBassin de Paris se déforme dans le temps en liaison possible avec des déplacements magmatiques et une activité séismique avortée. Le séisme du 11 juin 1938 en Belgique montre d'intéressants rapports avec l'anomalie magnétique belge. Les cartes isoporiques mondiales présentent des relations avec les cartes de séismicité (Omer). L'auteur pense que séismes et déformations du champ magnétique terrestre sont plus ou moins étroitement liés et que peut être une réaction atomiqueen chaine peut expliquer les séismes orogéniques et leurs répliques.
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    Le Precipitazioni Nevose nell'Italia Settentrionale: I (1948)
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    Pure and applied geophysics 12 (1948), S. 286-292 
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    Libri nuovi (1948)
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    Pure and applied geophysics 12 (1948), S. 295-296 
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    Note biografiche (1948)
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    Pure and applied geophysics 12 (1948), S. 293-294 
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    Neue Beiträge zum Aeroklima Nordamerikas (1948)
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    Pure and applied geophysics 12 (1948), S. 210-253 
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    ISSN: 1420-9136
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Description / Table of Contents: Summary In continuing former studies about the USA and in employing the recent observations—especially the ascents of radio-sounds—this investigation treats the average thermical conditions over the North-American continent in dependance from time and space till a height of about 20 km. The influences of the three geographical coordinates, i. e. latitude, longitude and height, and of the factor of time are developed gradually. The resulting consequences concerning the average conditions of pressure and air moving are derived and interpreted. In this manner one particularly succeeds in proving the effects of the distribution of the temperature on the planetary wind circulation, its modifications by the monsoon tendency and the component of the interhemispherical air circulation in the troposphere and in the stratosphere; a problem that has been explored relatively seldom till now. Furthermore the variations of the tropopause in time and space are shown. The study being a further contribution to a systematical development of a world-wide climatology of the free atmosphere will help to enlarge the necessary empirical foundation for all the theoretical speculations of the general circulation in the third dimension.
    Notes: Zusammenfassung In Fortführung früherer analoger Untersuchungen über die USA behandelt die vorstehende Arbeit unter Benutzung der seither hinzugekommenen Beobachtungen (namentlich von Radiosonden-Aufstiegen) die durchschnittlichen raum-zeitlichen Temperaturverhältnisse über dem nordamerikanischen Erdteil bis über 20 km Höhe. Die Einflüsse der drei geographischen Koordinaten: Breite, Länge, Höhe und des Zeitfaktors werden schrittweise herausgearbeitet, die sich daraus ergebenden Folgen für die mittleren Druck- und Bewegungsbedingungen abgeleitet und interpretiert. Auf diese Weise lassen sich insbesondere auch die Wirkungen der Temperaturverteilung auf die planetarische, die monsunale und die relativ noch wenig erforschte Komponente der interhemisphärischen Zirkulation in Tropo- und Stratosphäre, sowie die raum-zeitlichen Änderungen ihrer Trennungsfläche, der Tropopause, nachweisen. Die Arbeit ist im ganzen gedacht als ein weiterer Beitrag zur systematischen Entwicklung einer weltweiten Klimatologie des freien Luftmeeres, die das notwendige empirische Fundament für alle theoretischen Eröterungen des allgemeinen atmosphärischen Kreislaufs nach der dritten Dimension ausbauen soll.
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    Note biografiche (1948)
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    Pure and applied geophysics 12 (1948), S. 89-90 
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    Suscettivita' magnetica di alcuni minerali di magnetite (1948)
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    Pure and applied geophysics 12 (1948), S. 53-60 
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    Topics: Geosciences , Physics
    Description / Table of Contents: Summary The results of some measures of magnetic susceptibility of italian magnetic ores are reported and discussed. It is proved the impossibility of a general relation between the magnitude of the susceptibility and the genetic character of the ores; however, new views are pointed out to successfully deepen the results.
    Abstract: Zusammenfassung Die Ergebnisse einiger Suszeptibilitäts-Messungen von ital. Magnetit-Mineralien verschiedener Genesis werden angegeben und erläutert. U. a. beweist man, dass ein allgemeine Gesetz für eine einfache Zusammenhang zwischen den Werte der Suszeptibilität und die genetischen Eigentümlichkeiten der Lagerstätten nicht bestehen kann. Neue Forschungsrichtungen dafür werden vorgeschlagen.
    Notes: Riassunto Vengono esposti e discussi i risultati di alcune misure della suscetività magnetica di minerali magnetitiferi italiani. Fra l'altro si dimostra l'impossibilità di una legge generale di interdipendenza fra i valori della suscettività ed il carattere genetico dei giacimenti, indicando nuovi orientamenti per approfondire con successo simili indagini.
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    Libri nuovi (1948)
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    Pure and applied geophysics 12 (1948), S. 97-104 
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    Registrazione dei bradisismi costieri (1948)
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    Pure and applied geophysics 12 (1948), S. 113-120 
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    Description / Table of Contents: Zusammenfassung Man beschreibt ein Verfahren für eine mareographische Nivellierung womit man eine absolute vertikale Küstenbewegung bemessen kann und zwar unabhängig von der relativen Bewegung der Küste und des mittleren Wasserniveaus. Das Verfahren begründet sich auf die Bestimmung der Geschwindigkeiten der Zunahme (Zunahme in einer bestimmten Zwischenzeit) des mittleren Wasserniveaus aller Meere und von der gleichzeitigen Geschwindigkeit der Zunahme der mareographischen Station die geprüft werden soll. Mit diesen Bestimmungen ist es möglich ein fondamentales Niveau unverändert in Zeit und Raume festzustellen. Man bezeigt ausserdem wie das Verfahren eine Präzision eines mm für 200–400 km Küstenlänge geben kann. Man vergleicht die mareographische mit der geometrischen Nivellierung. Man gibt die Resultate der Anwendung dieses Verfahrens an der italienischen Küste.
    Notes: Riassunto Si descrive un procedimento di livellazione mareografica mediante il quale è possibile determinare la misura di un movimento verticale costiero in senso assoluto, cioè indipendentemente dai moti relativi della costa e del livello medio marino. Esso si basa sulla determinazione delle velocità dell'aumento (aumento in un dato intervallo di tempo) del livello medio marino di tutti i mari e di quella contemporanea della stazione in esame. Queste determinazioni rendono possibile di stabilire un piano fondamentale invariabile nel tempo e nello spazio. Si mette inoltre in evidenza come il procedimento possa dare una precisione che arriva sino al mm su zone costiere lunghe centinaia di km. Si confronta la livellazione mareografica con quella geometrica di precisione. Sono dati infine i risultati di una applicazione al caso delle coste italiane.
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    Elementi altimetrici dell'Istituto Geofisico e Geodetico dell'Universita' di Genova (1948)
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    Pure and applied geophysics 12 (1948), S. 162-167 
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    Description / Table of Contents: Zusammenfassung Der Verf. berichtet über das von ihm durchgeführte Feinnivellement um die vertikale Lage einiger Festpunkten des Geophysikalisch-Geodätischen Instituts der Universität Genua genau zu bestimmen und zwar mit Verbindung an die dortige mareographische Station.
    Notes: Riassunto L'A. riferisce sulla livellazione di precisione da lui eseguita per determinare le quote assolute dei caposaldi esterni ed interni dell'Istituto Geofisico e Geodetico dell'Università di Genova, con collegamento allo zero mareografico locale.
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    Eötvös zum Gedächtnis (1948)
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    Pure and applied geophysics 13 (1948), S. 1-3 
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    Misure di magnetismo terrestre in Ungheria (1948)
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    Pure and applied geophysics 13 (1948), S. 11-19 
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    Isostatic anomalies of transdanubia (Hungary) according to the gravity meter measurements (1948)
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    Pure and applied geophysics 13 (1948), S. 28-42 
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    Source: Springer Online Journal Archives 1860-2000
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    Notiziario (1948)
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    Pure and applied geophysics 13 (1948), S. 234-237 
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    URL: http://dx.doi.org/10.1007/BF01980385
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    Die kartographische Methode von R. Eötvös in ihrer heutigen Form (1948)
    Springer
    Pure and applied geophysics 13 (1948), S. 20-24 
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    Notes: Summary The Torsion Balance is to be used only in case if more information than presented by the Gravimeter is required. Being so, it is advisable then to make most of the fineness obtainable by the Torsion Balance. Therefore, a survey must be done carefully and reliably. One of its accessories is a proper calculus of the cartographic effects, specially for the curvature data which in their crude state — over a hilly topography — are of not much use. The cartographic method of Eötvös is right, for it works with a prism resting over a circle parcel which best fits the contourlines. The method itself is good, but Eötvös's approximate formulae — simple as they are — are accurate only within 2/10s of topographic elevation or depression. Generally speaking this limit is sufficient for the curvature data as beyond it they are rarely reliable. In order to speed up their evaluations from the map the author drew up a scale. On the other hand, for the gradient-effects a table was computed; it contains the effects of prisms of different heights at different distances. This table is handy in use; the basis used for it is the exact formula of gradient-effect. Same has to be done for curvature data beyond the two-tenth elevation. Suitably constructed tables for both effects may also be used for masses of three dimensions.
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    Über die Verlängerung der Periode Seismischer Wellen (1948)
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    Pure and applied geophysics 13 (1948), S. 75-87 
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    Notes: Zusammenfassung Seismische Wellen aller Art zeigen mit zunehmender Entfernung vom Quellpunkt eine Verlängerung ihrer Perioden. Zugleich findet eine Abnahme der Amplituden und ein Ausglätten der Bodenbewegung statt, die schliesslich, wie immer sie beschaffen gewesen sein mag, sinusartigen Charakter annimmt. Dieser Erscheinungskomplex wird durch die Theorie nicht wiedergegeben. In der vorliegenden Arbeit wird gezeigt, wo der Grund für diese Nichtübereinstimmung zwischen Theorie und Erfahrung liegen könnte. Er könnte einerseits in der Art und Weise zu suchen sein, wie die Diffgn. der Elastizitätstheorie integriert werden (die Dichte wird als konstant vorausgesetzt), er könnte aber auch darin liegen, dass die Erde kein vollelastisches, sondern ein visko-elastisches Medium ist. In jedem der beiden Fälle müsste, wenn sie berücksichtigt werden, der fragliche Erscheinungskomplex durch die Theorie wiedergegeben werden. Wahrscheinlich aber hat man beide Umstände zusammen zu berücksichtigen.
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    Notiziario (1948)
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    Pure and applied geophysics 13 (1948), S. 132-137 
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    Libri nuovi (1948)
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    Pure and applied geophysics 13 (1948), S. 138-144 
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    Beziehungen zwischen Globalstrahlung, Sonnenscheindauer und Bewölkung (1948)
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    Pure and applied geophysics 13 (1948), S. 157-166 
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    Description / Table of Contents: Résumé Les relations entre la radiation globale du soleil et du ciel, la durée de l'insolation et la nébulosité sont discuté. La proportion entre la radiation globale du ciel totalement couvert et du ciel totalement éclairci est une grandeur géophysique bien definie, laquelle est constante pour un éspace de la terre assez grand. Elle a une variation annuelle petite mais explicable et elle peut characteriser la structure moyenne des nuages. D'autre côté la constante «a» de l'équation deÅngström I M =I 0[1+(1−a)M] est très dependante du procès du calcul, elle est seulement la constante d'une équation d'interpolation. La supposition d'une relation linéaire entre la radiation globale et la nébulosité ou la durée rélative de l'insolation est remplie seulement en mesure réduite. Quelques valeurs du facteur «a» et de la proportion susmentionnée sont données.
    Abstract: Summary Some relations between the total radiation of sun and sky, the sunshine and the cloudiness are discussed. The relation of the total radiation on completely overcast days and on perfectly clear days is a well defined geophysical quantity, wich is constant about rather a large area of the earth. It has a slight but intellegible annual variation and has a physical meaning characterizing the structure of the clouds. Compared to this the constant ofÅngström's equationI M =I 0[1+(1−a)M] largely depends on how it is calculated. It is only the coefficient of a formula of interpolation. The supposing of a linear connection between the total incoming radiation and the cloudiness or the relative duration of sunshine is only fullfilled in a moderate degree. Some figures of «a» and the relation above mentioned are given.
    Notes: Zusammenfassung Es werden Zusammenhänge zwischen der Globalstrahlung, der relativen Sonnenscheindauer und der Bewölkung diskutiert. Das Verhältnis der Globalstrahlung bei völlig bedecktem Himmel zur Globalstrahlung bei völliger Wolkenlosigkeit ist eine klar definierte geophysikalische Grösse, die offenbar über grössere Räume hinweg konstant ist. Sie zeigt einen schwachen verständlichen Jahresgang und hat eine physikalische Bedeutung, indem sie die Struktur der Bewölkung charakterisiert. Die Konstante «a» derÅngströmschem GleichungI M =I 0[1+(1−a)M] ist demgegenüber in hohem Masse von der Art der Berechnung abhängig. Sie hat nur die Bedeutung einer Konstanten in einer Interpolationsformel. Dabei ist die Voraussetzung des linearen Zusammenhanges zwischen Globalstrahlung und Bewölkung oder relativer Sonnenscheindauer in Bochum nur in bescheidenem Masse erfüllt. Es werden eine Reihe von Zahlenwerten füra und das Verhältnis der Globalstrahlung bei bedecktem und wolkenfreiem Himmel mitgeteilt.
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    Methodische Betrachtungen zur regionalen Klimakunde (1949)
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    Pure and applied geophysics 14 (1949), S. 77-94 
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    Source: Springer Online Journal Archives 1860-2000
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    Description / Table of Contents: Summary The application to regional climatology of the synoptical elements is consistent with the conception of climate being the condensation of a variety of weather patterns. These elements are gained from analysis which is permitting the determination of air-masses (or air-bodies), frontal systems, and broad scale weather patterns. In this study it is attempted to arrive at an absolute system of air-masses. Improved technical conditions make it possible representing the distribution of individual meteor. elements, forming highly refined analyses of air-masses and frontal systems, and determining broad scale weather patterns. Statistical evaluation as well as investigations of the relationship between meteor. and geogr. factors point to modern climatology. This field of activity is part of basic research. Its practical applicability is in regional climatology and regional weather forecasting.
    Notes: Zusammenfassung Die Anwendung der synoptischen Grundlagen über das Wettergeschehen in der regionalen Klimakunde ist im Einklang mit der Definition des Klimas als der Gesamtheit der Witterung. Die Grundlagen werden aus der Analyse entnommen, welche die Bestimmung der Luftmassen (oder Luftkörper), Fronten und Grosswetterlagen zulässt. Die Erläuterung führt zu dem Versuch einer absoluten Luftmassengliederung. Verbesserte technische Voraussetzungen lassen die Darstellung von Einzelfeldern, die Feinanalyse von Luftmassen und Fronten sowie die Bestimmung der Grosswetterlage zu. Die statistische Auswertung sowie die Betrachtung des Zusammenhangs der meteorologischen Verhältnisse mit den geographischen Gegebenheiten führen zur modernen Klimakunde. Dieses Arbeitsgebiet gehört zur Grundlagenforschung. Die Nutzanwendung liegt in der Heimatklimakunde und in der regionalen Wettervorhersage.
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    Le correnti dell'alta troposfera e della stratosfera inferiore sulle regioni equatoriali (1949)
    Springer
    Pure and applied geophysics 14 (1949), S. 108-119 
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    Description / Table of Contents: Zusammenfassung Die Beobachtungen des Zirrenzuges in Mogadiscio während des Polarjahres 1932–33 werden zuerst zusammengefasst. Es folgt dann die Darstellung der Luftströmungen in der oberen Troposphäre auf Grund der Pilotballonvisierungen, woraus u.a. gezeigt wird, dass oft die Richtung des Zirrenzuges nicht mit derjenigen der herrschenden Luftströmungen zusammenfällt. Besonders durch die zahlreichen Beobachtungen des Zeitraumes 24.10-5-12.1932 werden die Eigentümlichkeiten dieser Strömungen eingehend erläutert und damit gezeigt, dass durch die Ablenkung derselben nach Nord oder Süd (für Nachgiebung der Fronten zwischen den O- und W-Strömungen und nachfolgende Senkung der Luftmassen) die Grosswetterlage in tropischen und auch in mittl. Breiten gesteuert und abgeändert wird. Die wenigen Beobachtungen weiche die Stratosphäre erreicht haben, lassen in der Höhe von etwa 30 km die Existenz einer Strömung wahrnehmen von fast gleicher Intensität wie der Krakatauwind, aber von entgegengesetzter Richtung (W). — Die besprochenen Ergebnisse zeigen ausserdem, dass das Bestehen der Ostströmungen in der unteren äquatoriellen Stratosphäre nicht allgemein gilt und dass auch dort die Tropopause nicht mit dem Maximum der Windgeschwindigkeit gekennezeichnet ist.
    Notes: Riassunto Riferiti i risultati delle osservazioni dei Cirri, vengono illustrate le caratteristiche delle correnti dell'alta troposfera su Mogadiscio in base ai lanci di palloni piloti eseguiti durante l'Anno Polare 1932–33, ponendo in luce, specialmente per il periodo dal 24–10 al 5-12-1932, il comportamento dettagliato delle correnti orientali ed occidentali, indicando come le deviazioni verso N e verso S di queste (per deformazione deifronti di contatto e successivo abbassamento delle masse d'aria) siano fattori determinanti delle condizioni del tempo in grande nelle regioni tropicali in grado d'influenzare anche quello delle latitudini medie e di giustificare quindi le relative singolarità. Le poche osservazioni stratosferiche hanno accertato una corrente all'incirca di eguale intensità, ma contraria di quella di Krakatoa: però in stagione diversa da quella dell'eruzione e delle osservazioni raccolte a Batavia.
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    A new conservation-theorem of hydrodynamics (1949)
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    Pure and applied geophysics 14 (1949), S. 189-193 
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    Description / Table of Contents: Zusammenfassung Der hier abgeleitete Erhaltungs-Satz sagt Folgendes aus: Wenn $$\vec v$$ die absolute Geschwindigkeit, $$\vec \xi = curl\vec v$$ den absoluten Wirbel, σ=σ(p) das spezifische Volumen einer barotropen Flüssigkeit und ΔW den Gradienten der Wirkungsfunktion bedeuten, so gilt: $$\frac{D}{{Dt}}\left\{ {\sigma {\text{ }}\vec \xi (\vec v - \nabla W)} \right\} = 0,$$ wobei $$\frac{D}{{Dt}}$$ die individuelle Zeitableitung der Hydrodynamik darstellt.
    Notes: Summary The conservation-theorem derived here can be expressed thus: Let $$\vec v$$ be the absolute velocity and $$\vec \xi = curl\vec v$$ the absolute vorticity, further σ=σ(p) the specific volume of a barotropic fluid and ΔW the gradient of the actionW (=Hamilton's principal-function), then $$\frac{D}{{Dt}}\left\{ {\sigma {\text{ }}\vec \xi (\vec v - \nabla W)} \right\} = 0,$$ where $$\frac{D}{{Dt}}$$ denotes differentiation following the motion of the fluid.
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    Variazioni del moto polare della Terra e loro correlazioni meteorologiche (1949)
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    Pure and applied geophysics 14 (1949), S. 197-202 
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    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Description / Table of Contents: Zusammenfassung Störungen in der Bewegung des Erdkörpers und Verschiebungen seiner Rotaktionsachse rufen Wirkungen hervor, welcke mit der Anpassung der Luftmassen an den neuen Bewegungen und an den neuen Lagen der Rotaktionsachse sich ausdrucken. Das führt zu Veränderungen der Luftströmungen, der Luftdruckverteilungen und daher der Grossewetterlagen. Einige meteorologischen Korrelationen dieser Art werden für die bedeutende Störung der Polarbewegung des 1923 gezeigt. Nachher werden damit besonders die starken Luftdruckanomalien erklärt, welche in Genua in der Periode 1924–32 beobachtet worden sind.
    Notes: Riassunto Vengono documentate ed illustrate alcune correlazioni fra le alterazioni del moto di rotazione terrestre iniziatesi nel 1923 con gli eventi meteorologici; in particolare si discutono e si spiegano in tal modo le forti anomalie della pressione osservate a Genova nel periodo 1924–32.
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    Damage to coastal villages due to the 1992 Flores Island earthquake tsunami (1995)
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    Pure and applied geophysics 144 (1995), S. 481-524 
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    ISSN: 1420-9136
    Keywords: Coastal damage due to tsunamis ; coeismic crustal motion ; aftershock area ; secondary tsunamis by induced landslides ; short arrival time of tsunami ; liquefaction ; sand blow ; relationship between tsunami height and ratio of mortality
    Source: Springer Online Journal Archives 1860-2000
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    Notes: Abstract A field survey of the 1992 Flores Island earthquake tsunami was conducted during December 29, 1992 to January 5, 1993 along the north coast of the eastern part of Flores Island. We visited over 40 villages, measured tsunami heights, and interviewed the inhabitants. It was clarified that the first wave attacked the coast within five minutes at most of the surveyed villages. The crust was uplifted west of the Cape of Batumanuk, and subsided east of it. In the residential area of Wuring, which is located on a sand spit with ground height of 2 meters, most wooden houses built on stilts collapsed and 87 people were killed even though the tsunami height reached only 3.2 meters. In the two villages on Babi Island, the tsunami swept away all wooden houses and killed 263 of 1,093 inhabitants. Tsunami height at Riang-Kroko village on the northeastern end of Flores Island reached 26.2 meters and 137 of the 406 inhabitants were killed by the tsumani. Evidence of landslides was detected at a few points on the coast of Hading Bay, and the huge tsunami was probably formed by earthquake-induced landslides. The relationship between tsunami height and mortality was checked for seven villages. The efficiencies of trees arranged in front of coastal villages, and coral reefs in dissipating the tsunami energy are discussed.
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    Laboratory experiments of tsunami runup on a circular island (1995)
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    Pure and applied geophysics 144 (1995), S. 569-593 
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    Keywords: Tsunamis ; tsunami runup ; laboratory experiments ; physical models ; three-dimensional models ; tsunami simulation ; solitary waves ; wavemakers ; tsunami evolution ; instrumentation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract Laboratory experiments of a 7.2-m-diameter conical island were conducted to study three-dimensional tsunami runup. The 62.5-cm tall island had 1 on 4 side slopes and was positioned in the center of a 30-m-wide by 25-m-long flat-bottom basin. Solitary waves with height-to-depth ratios ranging from 0.05 to 0.20 and “source” lengths ranging from 0.30 to 7.14 island diameters were tested in water depths of 32 and 42 cm. Twenty-seven capacitance wave gages were used to measure surface wave elevations at incident and four radial transects on the island slope. Maximum vertical runup measurements were made at 20 locations around the perimeter of the island using rod and transit. A new runup gage was located on the back or lee side of the island to record runup time series.
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    Field survey of the 1993 Hokkaido Nansei-Oki earthquake tsunami (1995)
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    Pure and applied geophysics 144 (1995), S. 649-663 
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    ISSN: 1420-9136
    Keywords: Tsunami ; runup ; arrival time ; edge wave ; Japan Sea
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract Runup data in Hokkaido and in three prefectures in the Tohoku District are described with a few witnessed arrival times and with comments of tide records. The highest runup of 31.7 m was found at the bottom of a narrow valley on the west coast of Okushiri Island. In order to explain high runups of 20 m at Hamatsumae in the sheltered area, roles of edge waves, refraction of the Okushiri Spur and tsunami generation by causes other than the major fault motion should be understood. An early arrival of the tsunami on the west coast of Hokkaido suggests another tsunami generation mechanism in addition to the major fault motion.
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    Scaling relations for seismic events induced by mining (1995)
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    Pure and applied geophysics 144 (1995), S. 191-209 
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    ISSN: 1420-9136
    Keywords: Induced seismicity ; scaling relations ; self-similar behavior ; P- andS-wave corner frequencies
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract The values of seismic moment andS-wave corner frequency from 1575 seismic events induced in South African, Canadian, Polish, and German underground mines were collected to study their scaling relations. The values ofP-wave corner frequency from 649 events were also available. Seismic moments of these events range from 5*103 to 2*1015 N·m (moment magnitude is from −3.6 to 4.1), theS-wave corner frequency ranges from 0.7 to 4438 Hz, and theP-wave corner frequency is between 5 and 4010 Hz. The slope of a regression line between the logarithm ofS- andP-wave corner frequencies is equal to one, and the corner frequencies ofP waves are higher than those ofS waves on the average by about 25 percent. In studies of large and moderate earthquakes it has been found that stress drop is approximately independent of the seismic moment, which means that seismic moment is inversely proportional to the third power of corner frequency. Such a behavior was confirmed for most of the data considered here. A breakdown in the similarity betwen large and small events seems to occur for the events with moment magnitude below −2.5. The average values of seismic moment referred to the same range of corner frequency, however, are vastly different in various mining areas.
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    A study of rupture length vs. moment for synthetic earthquakes (1995)
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    Pure and applied geophysics 144 (1995), S. 211-228 
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    ISSN: 1420-9136
    Keywords: Mass-spring model ; seismic moment ; earthquake moment ; rupture length ; fractal ; velocity-dependent friction law
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract From the events synthesized from the one-dimensional dynamical mass-spring model proposed byBurridge andKnopoff (1967), the relation between rupture length Δ and earthquake momentM is studied for various model parameters. The earthquake moment is defined to be the total displacement of a connected set of mass elements which slide during an event. A parameter stiffness ratios is defined as the ratio of the spring constant between the two mass elements to that between one mass element and the moving plate. The velocity-dependent friction law (including weakening and hardening processes) is taken to control the sliding of a mass element. The distribution of the breaking strengths over the system is considered to be a fractal function. The cases for severals values and different velocity-dependent friction laws with different decreasing ratesr w of the frictional force with sliding velocity are studied numerically. The weakening process of the frictional force from the static one to the dynamic one obviously affects theM−Δ relation. Meanwhile, a rapid weakening process rather than a slow weakening process can result in aM−Δ relation, which is comparable to the observed one. Although an increase in thes value can yield an increase in the upper bound of the Δ value and the number of events with largeM and Δ values, the scaling of theM−Δ relation is not affected by the change of thes value. For the cases in this study, the theoretical Δ−M relations for small events withM〈1 are almost in the form: Δ∼M 1/2, while those for large events withM〉1 have a scaling exponent less than but close to 1. In addition, the fractal dimension, the friction drop ratio and the roughness of the distribution of the breaking strengths over the fault surface are the minor parameters influencing the Δ−M relation. A comparison between the theoreticalM−Δ relation and the observed one for strike-slip earthquakes shows that for large events the theoreticalM−Δ relation is quite consistent with the observed one, while for small events there is a one-order difference in the two relations. For the one-dimensional model, the decreasing rate of the dynamic frictional force with velocity is the main factor in affecting the characteristic value of the earthquake moment, at which the scaling of theM−Δ relation changes.
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    Bayesian probabilities of earthquake occurrences in Greece and surrounding areas (1995)
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    Pure and applied geophysics 144 (1995), S. 307-319 
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    Keywords: Greece ; hazard ; Bayesian probabilities
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract The Bayesian extreme-value distribution of earthquake occurrences has been adopted to estimate the seismic hazard in some seismogenic zones in Greece and surrounding regions. Seismic moment, slip rate, earthquake recurrence rate and magnitude were considered as basic parameters for computing the prior estimates of the seismicity. These estimates are then updated in terms of Bayes' theorem and historical estimates of seismicity associated with each zone. High probabilities for earthquakes withM≥6.0 have been obtained for the northwestern part of Greece as well as for the southwestern part of the Hellenic arc.
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    Physical, radiative, and dynamical processes within a nighttime marine stratus cloud (1995)
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    Pure and applied geophysics 144 (1995), S. 321-350 
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    ISSN: 1420-9136
    Keywords: Marine stratus ; aircraft observations ; IR cooling ; dynamical and physical processes ; moisture and heat fluxes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract Observations taken by aircraft and conventional platforms are used to investigate dynamical, physical, and radiative processes within a marine stratus cloud during the Canadian Atlantic Storms Program (CASP) II field project which took place over the east coast of Canada. Stratus which formed over the ocean on February 6, 1992 during the nighttime, is studied to analyze cloud top and base processes. The cloud was supercooled during the study period. Fluctuations and fluxes are calculated along constant flight altitude legs approximately 100 km long in space. The scales of structures larger than 5 km are removed from the analysis using a running average technique. Droplet spectra obtained by a forward scattering spectrometer probe (FSSP) were used in a 1-D radiative transfer model to calculate infrared (IR) fluxes and radiative heating rates. A heat conservation equation was used to estimate vertical air velocity (w a ) within the cloud. The results showed that, because of a warmer ocean surface, significant moisture and heat were transferred from the ocean surface to the boundary layer. The cloud base was at about 400 m height and the top was at about 1.4 km.w a at the cloud base was estimated about 5 cm s−1. Strong IR cooling rate at the cloud top was calculated to be 75°C day−1 for a 100 m thick layer. Negative skewness inw a , suggesting narrow downdrafts, was likely due to radiative cooling at the cloud top. The entrainment velocity was found to be about 1.5 cm s−1 at cloud top. Mean moisture and heat fluxes within the cloud were estimated to be comparable to those from the ocean surface. Vertical air velocity at the cloud top due to radiative cooling was found to be about −40 cm s−1.
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    Book reviews (1995)
    Springer
    Pure and applied geophysics 144 (1995), S. 351-372 
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    ISSN: 1420-9136
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00878639
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    Analysis and automatic processing in near-field of eight 1992–1994 tsunamigenic earthquakes: Improvements towards real-time tsunami warning (1995)
    Springer
    Pure and applied geophysics 144 (1995), S. 381-408 
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    ISSN: 1420-9136
    Keywords: Tsunami ; tsunami earthquakes ; seismic moment ; mantle magnitude
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract We study eight tsunamigenic earthquakes of 1992–1994 with data from single near-field 3-component long-period stations. The analysis is made from the standpoint of tsunami warning by an automatic process which estimates the epicentral location and the seismic moment through the variable-period mantle magnitudeM m . Simulations of early warning based on the real-time computation of the seismic moment are also tested with this system, which would give a justified warning in each region of tsunami potentiality. By exploiting the dependence of moment rate release with frequency, the system has the capability of recognizing both “tsunami earthquakes” such as the 1992 Nicaragua and 1994 Java events, as well as instances of the opposite case of low-frequency deficiency, interpreted as indicating a deeper than normal source (1993 Guam event). We report both the results of delayed-time processing of the near-field stations, and the actual real-time warnings at PPT, which confirm the former.
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    URL: http://dx.doi.org/10.1007/BF00874374
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    Source parameters of mining-induced seismic events: An evaluation of homogeneous and inhomogeneous faulting models for assessing damage potential (1995)
    Springer
    Pure and applied geophysics 145 (1995), S. 3-27 
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    ISSN: 1420-9136
    Keywords: Mining-induced seismicity ; faulting models ; peak ground parameters
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract Source parameter estimates based on the homogeneous and inhomogeneous source models have been examined for an anomalous sequence of seven mine-induced events located between 640 and 825 m depth at Strathcona mine, Ontario, and having magnitudes ranging betweenm N 0.8 and 2.7. The derived Brune static stress drops were found to be similar to those observed for natural earthquakes (∼30 bars), whereas dynamic stress drops were found to range up to 250–300 bars. Source radii derived from Madariaga's model better fit documented evidence of underground damage. These values of source radii were similar to those observed for the inhomogeneous model. The displacement at the source, based on the observed attenuation relationship, was about 60 mm for three magnitude 2.7 events. This is in agreement with slip values calculated using peak velocities and assuming the asperity as a Brune source within itself (72 mm). By using Madariaga's model for the asperity, the slip was over 3 times larger than observed. Peak velocity and acceleration scaling relations with magnitude were investigated by incorporating available South African data, appropriately reduced to Canadian geophysical conditions. The dynamic stress drop scaled as the square root of the seismic moment, similar to reported results in the literature for crustal earthquakes. This behavior suggests that the size of the asperities responsible for the peak ground motion, with respect to the overall source size, follow distributions that may be similar over a wide range of magnitudes. Measurements of source rupture complexity (ranging from 2 to 4) were found to agree with estimates of overall source to asperity radii, suggesting, together with the observed low rupture velocities (0.3 β to 0.6 β), that the sources were somewhat complex. Validation of source model appropriateness was achieved by direct comparison of the predicted ground motion level to observed underground damage in Creighton mine, located within the same regional stress and geological regime as Strathcona mine. Close to the source (〈100 m), corresponding to relatively higher damage levels, a good agreement was found between the predicted peak particle velocities for the inhomogeneous model and velocities derived based on established geomechanical relationships. The similarity between asperity radii and the regions of the highest observed damage provided additional support for the use of the inhomogeneous source model in the assessment of damage potential.
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    URL: http://dx.doi.org/10.1007/BF00879480
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    Research on earthquakes induced by water injection in China (1995)
    Springer
    Pure and applied geophysics 145 (1995), S. 59-68 
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    ISSN: 1420-9136
    Keywords: Earthquakes ; water injection ; oil field
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract In China, the earthquakes induced by water injection have occurred in four oil fields including the Renqiu oil field, and in two mines. Production of oil from the Renqiu oil field began in 1975 and the injection of water into the oil field commenced in July 1976. The induced earthquakes have been occurring in the area for the past 17 years, since December 1976. The controlled experiments of water injection showed the cause and effect relation between water injection and earthquakes. Source parameters such as source dimension, seismic moment and stress drop of a large number of the induced earthquakes, andQ factor for the area have been determined. The results indicate that the stress drop varies from 0.2 to 3.0 bar and theQ factor has an average value of 75.0. The low-stress drop and lowQ factor values imply that the earthquakes are caused by the brittle fracture of weak rocks under low ambient stresses, due to a decrease in their strength because of the injection of water. The induced earthquakes are unevenly distributed in the oil field. The northern part of the oil field, where the reservoir rocks are characterized by low porosity and low permeability, exhibits high seismic activity with the largest earthquake registering a magnitude of 4.5 and about 68% of the total number of induced earthquakes in this part. Whereas, the southern part of the oil field with higher porosity and higher permeability is characterized by low seismic activity with the largest earthquake registering a magnitude of 2.5 and only 4% of the total number of earthquakes which occurred in this part. These features of the focal region suggest that larger earthquakes may not occur in the Renqiu oil field area.
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    URL: http://dx.doi.org/10.1007/BF00879483
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    Source model of Noto-Hanto-Oki earthquake tsunami of 7 February 1993 (1995)
    Springer
    Pure and applied geophysics 144 (1995), S. 621-631 
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    ISSN: 1420-9136
    Keywords: Noto-Hanto-Oki earthquake tsunami ; source model ; spectral synthesis ; numerical simulation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract A source model was discussed for a small tsunami accompanied by the Noto-Hanto-Oki earthquake (M s 6.6), striking Japan on 7 February, 1994. Assuming a fault model under the sea bottom, we estimated the focal parameters jointly, using synthesized tsunami source spectra as well as the tsunami numerical simulation. The fault proposed by this study consists of a plane sized 15×15 km, dipping N47°W with the dip angle of 42°, which is almost pure reverse fault (slip angle 87°) with a dislocation of 1 meter. The numerical simulation shows that the shallow sea in the source region caused a comparatively long recurring tsunami (the periods are 12–18 minutes) in spite of its small size. The model fault is corresponding to an aftershock area of this earthquake.
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    URL: http://dx.doi.org/10.1007/BF00874386
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    Two 1993 Kamchatka earthquakes (1995)
    Springer
    Pure and applied geophysics 144 (1995), S. 633-647 
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    ISSN: 1420-9136
    Keywords: Earthquake parameters ; tsunamis ; earthquake cycle
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract Two earthquakes occurred in 1993 off southern Kamchatka. They have similar surface wave magnitudes, focal mechanisms, and depths, but have distinctly different characteristics. The November earthquake is a standard or “impulsive”M7 underthrusting event. The June earthquake is a tsunamigenic or “low-stress-drop” event with several unusual characteristics, including a large, diffuse aftershock zone, directivity, and a long source time function. The 1993 earthquakes ruptured a segment of the Kamchatka Arc which has not ruptured since 1904. The 1993 earthquakes seem to signal the midpoint in the southern Kamchatka seismic cycle.
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    Tsunami deposits from the 1993 Southwest Hokkaido earthquake and the 1640 Hokkaido Komagatake eruption, northern Japan (1995)
    Springer
    Pure and applied geophysics 144 (1995), S. 719-733 
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    ISSN: 1420-9136
    Keywords: Tsunami deposit ; distribution ; lithofacies ; 1993 Hokkaido tsunami ; 1640 Komagatake eruption
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract The southwest Hokkaido tsunami of July 12th, 1993, left continuous onshore sand deposits along the west coast of Oshima Peninsuka, Hokkaido, northern Japan. We investigated spatial distribution and lithofacies of the new tsunami deposits for its identification of ancient tsunami deposits. An eyewitness acount and bent plants helped our interpretation of the onshore tsunami behavior. We regard the following properties as typical of the coastal tsunami sand deposits: (1) The deposits cover the surface almost continuously on gentle topography. (2) Deposit thicknesses and mean grain sizes descrease with distance from the sea. (3) Deposit thicknesses and lithofacies vary greatly across local surface undulation. (4) Graded bedding reflecting tsunami runup and backwash is present in thick deposits. (5) The deposits are widely distributed along the coast and extend inland several tens of meters to 100 m. We examined a candidate for the paleo-tsunami deposits associated with the 1640 Komagatake eruption, and confirmed that the similar patterns are typical of ancient tsunami deposits.
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    URL: http://dx.doi.org/10.1007/BF00874391
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    Role of dykes in induced seismicity at Bhatsa reservoir, Maharashtra, India (1995)
    Springer
    Pure and applied geophysics 145 (1995), S. 155-165 
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    ISSN: 1420-9136
    Keywords: Dykes ; pore pressure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract The geological and hydrological conditions near the reservoir site play an important role in the generation or absence of seismic activity. Near Bhatsa reservoir, along the west coast of India intense seismic activity occurred during August–September 1983, after a lag of six years of initial impounding. From July 1983 to September 1990, 15,388 earthquakes (mostlyM 1〈3.0) were recorded, the largest being of magnitude 4.9. The spatial distribution of well located 172 earthquakes suggest a strong correlation between the epicenters and the disposition of dykes and faults around the Bhatsa region. It is inferred that these dykes have acted as “barriers” for the diffusion of water from the reservoir, thereby becoming zones of instability due to increased pore pressure not only along them but also over the volume they bound.
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    URL: http://dx.doi.org/10.1007/BF00879491
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    Reservoir associated characteristics using deterministic chaos in Aswan, Nurek and Koyna reservoirs (1995)
    Springer
    Pure and applied geophysics 145 (1995), S. 209-217 
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    ISSN: 1420-9136
    Keywords: Earthquakes ; strange attractor ; deterministic chaos ; reservoir
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract Nurek, Aswan and Koyna reservoirs were affected by moderate earthquakes with continuing seismic activity. Microearthquake data recorded through local networks have been used to determine the strange attractor dimensions, using deterministic chaos which were found as 7,2, 3.8 and 4.8, respectively. This would imply that while 8 parameters are needed to model earthquakes near Nurek reservoir, only 4 to 5 parameters are needed for the Aswan and Koyna regions. The differences in the strange attractor dimension suggest them to be a measure of seismotectonics around such reservoirs.
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    Use of mode-converted waves in marine seismic data to investigate the lithology of the sub-bottom sediments in Isfjorden, Svalbard (1995)
    Springer
    Pure and applied geophysics 145 (1995), S. 313-325 
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    ISSN: 1420-9136
    Keywords: Mode-conversion ; marine/land geometry ; V p /V s ratios ; lithology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstracts The compression wavefield is efficiently converted to shear-wave energy at post-critical angles in areas of high impedance contrast at the sea floor. We have analysed mode-converted shear waves in a data set acquired with a hybrid marine/land geometry in Isfjorden, Svalbard. Through a kinematic 2D ray-tracing modellingV p/Vs ratios for part of the uppermost 5km of the crust are obtained. Low values (V p /V s =1.65) are tentatively associated with the section of Devonian sandstones which appears to attain a minimum thickness of 1.5km below 3 km depth about 10km west of Kapp Thorden.
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    Macroseismic information from historic pictorial sources (1996)
    Springer
    Pure and applied geophysics 146 (1996), S. 103-111 
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    ISSN: 1420-9136
    Keywords: Prephotographic earthquake depictions ; pictorial macroseismic data ; historical seismicity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract Prephotographic depictions of earthquakes can contain important information on the types and amount of damage due to a large earthquake in historic times. Care must be used in evaluating such depictions because some are more accurate than others, and many depictions contain little that is of value in making estimates of seismic intensity. Depictions of two earthquakes, in 1692 at Jamaica and in 1843 at Guadeloupe, illustrate the utility of depictions in intensity estimation. A depiction of the scene at Port Royal in Jamaica of the 1692 shock suggests that the major damage was caused by soil slumping and a tsunami, with the ground shaking itself probably only having been about MMI VII. Two depictions of Pointe-à-Pitre at Guadeloupe after the 1843 event contain evidence that the town was damaged by strong ground shaking as well as by major soil failures. The ground shaking here was probably MMI VII–IX. These and other pictures are being assembled for a monograph of prephotographic earthquake depictions in the Americas.
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    Historical 1942 Ecuador and 1942 Peru subduction earthquakes and earthquake cycles along Colombia-Ecuador and Peru subduction segments (1996)
    Springer
    Pure and applied geophysics 146 (1996), S. 67-101 
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    ISSN: 1420-9136
    Keywords: Earthquke cycle ; source parameters ; seismic moment ; fault heterogeneity ; P waveforms ; historical earthquakes ; source time function ; seismic gap
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract Two large shallow earthquakes occurred in 1942 along the South American subduction zone inclose proximity to subducting oceanic ridges: The 14 May event occurred near the subducting Carnegie ridge off the coast of Ecuador, and the 24 August event occurred off the coast of southwestern Peru near the southern flank of the subducting Nazca ridge. Source parameters for these for these two historic events have been determined using long-periodP waveforms,P-wave first motions, intensities and local tsunami data. We have analyzed theP waves for these two earthquakes to constrain the focal mechanism, depth, source complexity and seismic moment. Modeling of theP waveform for both events yields a range of acceptable focal mechanisms and depths, all of which are consistent with underthrusting of the Nazca plate beneath the South American plate. The source time function for the 1942 Ecuador event has one simple pulse of moment release with a duration of 22 suconds, suggesting that most of the moment release occurred near the epicenter. The seismic moment determined from theP waves is 6–8×1020N·m, corresponding ot a moment magnitude of 7.8–7.9. The reported location of the maximum intensities (IX) for this event is south of the main shock epicenter. The relocated aftershcks are in an area that is approximately 200 km by 90 km (elongated parallel to the trench) with the majority of aftershocks north of the epicenter. In contrast, the 1942 Peru event has a much longer duration and higher degree of complexity than the Ecuador earthquake, suggesting a heterogeneous rupture. Seismic moment is released in three distinct pulses over approximately 74 seconds; the largest moment release occurs 32 seconds after rupture initiation. the seismic moment as determined from theP waves for the 1942 Peru event is 10–25×1020N·m, corresponding to a moment magnitude of 7.9–8.2. Aftershock locations reported by the ISS occur over a broad area surrounding the main shock. The reported locations of the maximum intensities (IX) are concentrated south of the epicenter, suggesting that at least part of the rupture was to the south. We have also examined great historic earthquakes along the Colombia-Ecuador and Peru segments of the South American subduction zone. We find that the size and rupture length of the underthrusting earthquakes vary between successive earthquake cycles. This suggests that the segmentation of the plate boundary as defined by earthquakes this century is not constant.
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    Modeling fragmentation in two dimensions (1996)
    Springer
    Pure and applied geophysics 146 (1996), S. 115-129 
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    ISSN: 1420-9136
    Keywords: Fragmentation ; fractal distributions ; self-similarity ; self-organized criticality ; cellular automatons ; computer models
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract Three cellular automaton “toy”-models of fragmentation in two-dimensional lattices are explored. Of the three models, two can be considered in the class of simple bond percolation, and one as correlated bond percolation. Fractal fragment-size distribution in all models is found away from criticality, providing a certain fraction of the bonds is designated with considerably larger strengths than the rest in the system. As the fraction of these bonds is raised from zero, the fragment-size distribution transforms smoothly from exponential forms into a power law. Though each model takes a different path to the fractal distribution, they all show the same fractal exponent of 1.85(5). As might be expected in one dimension, the same models of their variants, failed to produce fractal distributions.
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    Multifractal measures of earthquakes in west Taiwan (1996)
    Springer
    Pure and applied geophysics 146 (1996), S. 131-145 
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    ISSN: 1420-9136
    Keywords: Multifractal ; general fractal dimension ; epicentral distribution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract The generalized fractal dimension for epicentral distribution of earthquakes in west Taiwan is measured. The entire area is first divided into two zones, i.e., north and south zones, after which the two zones are further separated into three subzones for the former and two for the latter. The logC q (r) versus logr function, whereC q (r) is the generalized correlation integral andr is the distance between two epicenters, shows that a linear relation between logC q and logr exists in the range ofr smaller thanr c . The value ofr c is 25 km for the north zone, 40 km for the south and 12 km for the three north subzones. The valuesr c =25 and 40 km are almost the smallest ones of the width of epicentral distributions of the north and south zones, respectively. The value ofr c =12 km for the three north subzones is approximately the smallest size of the cluster of epicenters. For the plots of two south subzones, the pattern of data points does not bend in the range ofr in consideration, and, thus, there is not such a critical radius. TheD q −q relations forq=0, 1, 2,..., 15 are constructed for the two zones and five subzones. Results show significant multifractality and a spatial variation in multifractality for epicentral distributions of earthquakes in west Taiwan.
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    Book review (1996)
    Springer
    Pure and applied geophysics 146 (1996), S. 195-205 
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    ISSN: 1420-9136
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00876676
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    Strong motion records and synthetic isoseismals of the Pyrgos, Peloponnisos, Southern Greece, Earthquake Sequence of March 26, 1993 (1996)
    Springer
    Pure and applied geophysics 146 (1996), S. 147-161 
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    ISSN: 1420-9136
    Keywords: Greece ; strong motion ; synthetic isoseismals
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract In this work, several seismological observations are presented in order to explain characteristic features of the earthquake sequence which occurred in March 1993 in southwestern Greece, very close to the city of Pyrgos. Fault plane solutions of the largest fore- and aftershocks and the main shock, as well as the directions at which the maximum ground accelerations were recorded suggest that this earthquake sequence has been developed by rupturing three distinct focal planes with different focal mechanisms. The first focal plane, located in the off-shore area, strikes NW-SE, dips SE and includes most of the foreshock activity. The foreshock activity migrated to the northeastern part of the city of Pyrgos and took place on planes with a predominant direction NE-SW. The main shock ofM x =5.5 occurred in a focal plane located between the two above-mentioned areas. Strong motion records of significant shocks of the sequence show peak acceleration values on components consistent with the relevant fault plane solutions. Furthermore, the observed macroseismic field has been compared with synthetic isoseismals computed by using a certain velocity model and the focal mechanism parameters of the main shock.
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    Non-linear predictions ofAp by activity class and numerical value (1996)
    Springer
    Pure and applied geophysics 146 (1996), S. 163-193 
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    ISSN: 1420-9136
    Keywords: Ap geomagnetic index ; magnetic activity forecasting ; non-linear prediction ; back-propagation neural network ; probabilistic neural network
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract Two neural network algorithms are applied to the short-term,1 to 3 days, prediction of theAp geomagnetic index. A multi-layer, back-propagation (MBP) network is used to implement a self-prediction filter forAp and this provides a forecast of the numerical value of the index. A probabilistic neural network (PNN) is used to estimate the probability distribution of theAp index, in six activity classes, and to provide a forecast of the single most likely activity class for each day. BothAp and an index of solar activity, based on the daily reports issued by the Space Environment Services Centre (Boulder), are input to the probabilistic net. It is found that the numerical forecasts of the MBP filter are most accurate at low, non-storm, levels of activity. This non-linear method provides quantitatively better estimates of activity than are produced by an existing linear prediction filter, particularly with increasing forward forecasting lag. At high levels of the solar activity index the PNN is found to anticipate storm classAp with around 60% accuracy in 1992 and 1993. Some details of the algorithms and implementation issues are described. It is concluded that interplanetary field and solar wind data will be significant components of any of the possible future developments which are discussed.
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    Transport properties and microstructural characteristics of a thermally cracked mylonite (1996)
    Springer
    Pure and applied geophysics 146 (1996), S. 207-227 
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    ISSN: 1420-9136
    Keywords: Transport properties ; pore microstructure ; porosity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract An experimental study was carried out on a granitic mylonite (La Bresse, France) to analyze the influence of pore microstructure on transport properties. Different crack networks were obtained by a controlled thermal treatment. Microstructures were analyzed by means of gas adsorption and mercury porosimetry. Transport properties have been investigated by measuring gas permeability and electrical conductivity. The dependence of permeability on confining pressure shows an exponential decrease, characteristic of a porosity made of cracks. Correlations between measured parameters have been analyzed by comparing them with relations deduced from theoretical models. Linking the formation factor to the porosity leads to a rather low tortuosity value (about 2.4), characterizing a medium with a well connected porosity. Correlation between permeabilityk and formation factorF leads to a power-law relationk ∝ F −n wheren≈2.9, which is consistent with a crack model describing the behavior of the thermally treated rock.
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    Evolution of localized folding for a thin elastic layer in a softening visco-elastic medium (1996)
    Springer
    Pure and applied geophysics 146 (1996), S. 229-252 
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    ISSN: 1420-9136
    Keywords: Localized folding ; softening visco-elastic medium ; instability of layer
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract Long compressed elastic struts on softening elastic foundations have a tendency to buckle locally. The same tendency is demonstrated here for the instantaneous response of elastic struts supported by visco-elastic media. A governing nonlinear partial differential equation is derived to describe the evolution of the localized form in time. Under the assumed constant end-shortening this is found to be approximated by a coupled set of seven ordinary differential (diffusion) equations. As the load drops to zero, the localized buckle pattern evolves towards the form of the single long wave, but remains aperiodic for all time. Three-dimensional plots show how this localized pattern changes over time.
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    Space-time variations of the frequency-energy relation for mining-induced seismicity in the Ostrava-Karviná mining district (1996)
    Springer
    Pure and applied geophysics 146 (1996), S. 265-280 
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    ISSN: 1420-9136
    Keywords: Induced seismicity ; b-value statistics ; Ostrava-Karviná Coal Mine District
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract The values of parameters of the relation logN=a−b logE characterize in general the level of seismicity of individual regions. In the present paper, a detailed analysis ofb values of the frequency-energy distributions was carried out with the aid of a database of seismic events recorded by the seismological networks in the Ostrava-Karviná Coal Mine District (Czech Republic), using the least squares regression and maximum likelihood method, as well. The determination ofb value was performed for a relatively large number of regions investigated and for different time series of observations. Special attention has been paid to induced seismic events statistics for the vicinity of one of the coalfaces in the Lazy Mine. It could be generally stated that lowerb values correspond to a higher level of induced seismic activity, while the higher ones correspond to a low and a moderate seismic activity.
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    A two-stage model of fracture of rocks (1996)
    Springer
    Pure and applied geophysics 146 (1996), S. 253-263 
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    ISSN: 1420-9136
    Keywords: Fracture ; fault nucleation ; critical crack density ; hierarchic failure ; earthquakes ; thermal activation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract In this paper we propose a two-stage model of rock fracture. In the first stage, cracks or local regions of failure are uncorrelated and occur randomly throughout the rock in response to loading of pre-existing flaws. As damage accumulates in the rock, there is a gradual increase in the probability that large clusters of closely spaced cracks or local failure sites will develop. Based on statistical arguments, a critical density of damage will occur where clusters of flaws become large enough to lead to larger-scale failure of the rock (stage two). While crack interaction and cooperative failure is expected to occur within clusters of closely spaced cracks, the initial development of clusters is predicted based on the random variation in pre-existing flaw populations. Thus the onset of the unstable second stage in the model can be computed from the generation of random, uncorrelated damage. The proposed model incorporates notions of the kinetic (and therefore time-dependent) nature of the strength of solids as well as the discrete hierarchic structure of rocks and the flaw populations that lead to damage accumulation. The advantage offered by this model is that its salient features are valid for fracture processes occurring over a wide range of scales including earthquake processes. A notion of the rank of fracture (fracture size) is introduced, and criteria are presented for both fracture nucleation and the transition of the failure process from one scale to another.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00876492
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  • 97
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    Regional moments, energy levels, and a new discriminant (1996)
    Springer
    Pure and applied geophysics 146 (1996), S. 281-304 
    Details
    ISSN: 1420-9136
    Keywords: Energy discriminant ; magnitude ; amplitude ; earthquake ; explosion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract Teleseismic observations of explosions tend to be richer in short-period energy than are earthquakes, thus the effectiveness of them b ∶M s discriminant. At regional distances the same basic separation occurs for smaller events in terms ofM L ∶M 0 (Woods et al., 1993) andm b ∶M 0 (Patton andWalter, 1993). While these studies demonstrate the basic differences in excitation, they suffer in practical application because of the detailed information required in the retrieval ofM 0 . In this paper, we introduce a new method of discrimination, based on the energy strength (M E ) from broadband regional records that appears to be effective and efficient. In this method all events are processed as earthquakes, and explosions are distinguished by their stronger energy levels relative to their long-period amplitudes. Results from 29 events recorded by TERRAscope, sampling 15 explosions from NTS and 14 earthquakes from the southwestern United States, are represented, indicating complete separation (45 data points).M L =3.6 is the smallest event examined to date but the method can probably be extended to even smaller levels in calibrated regions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00876494
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  • 98
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    Mt. Melbourne volcano, antarctica: Evidence of seismicity related to volcanic activity (1996)
    Springer
    Pure and applied geophysics 146 (1996), S. 305-318 
    Details
    ISSN: 1420-9136
    Keywords: Volcanic seismicity ; polarization analysis ; Q ; volcanic processes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract Characterization of the microseismic activity (M L 〈2.0) has been performed at Mt. Melbourne since 1990. We recorded a group of low frequency events with common morphological characteristics, i.e., an emerging onset, an unclear second phase and a sharply dropping coda. Spectral analysis of events recorded at more than one station indicates that the seismogram characteristics and spectral content are largely due to source effects. A polarization filter applied to a set of three component data revealed a first phase made up ofP waves followed (after about 0.9–1.4 sec.) by a second phase probably composed ofSH-type waves. Particle motion analysis detected a seismic ray angle direction mainly between N70°E and N110°E and apparent angle of incidence between 35° and 48° for the first phase. The studied seismicity was localized in an area on the eastern slope of Mt. Melbourne Volcano which presents a surface temperature anomaly (Mazzarini andSalvini, 1994). We formulate two hypotheses for the type of earthquakes recorded: 1) long-period events involving active presence of magmatic fluids in the source processes; 2) or the result of fracturing processes (shear?) in a medium characterized by transition between brittle and plastic behaviors. In the latter hypothesis the superficial thermal anomaly may be a symptom of this behavior at depth and is confirmed by the lown values observed for the exponential fit in the codaQ analysis.
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    URL: http://dx.doi.org/10.1007/BF00876495
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  • 99
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    A direct method of calculating interval velocities and layer thicknesses from wide-angle seismic reflection times (1996)
    Springer
    Pure and applied geophysics 146 (1996), S. 343-363 
    Details
    ISSN: 1420-9136
    Keywords: Wide-angle reflection times ; interval velocities and thicknesses ; stripping method
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract Wide-angle reflections are now routinely recorded in high resolution explosion seismics to study the crustal structure. Use of Dix's hyperbolic approximation to the nonhyperbolic wide-angle reflection travel times causes major errors in the determination of interval velocities and layer thicknesses of a stack of horizontal velocity layers. Here we propose a layer stripping method to directly calculate the interval velocities and layer thicknesses in a vertically heterogeneous earth from the strong and reliable wide-angle reflected events. Synthetic reflection travel times, at wide-angle range, for a given velocity model, contaminated by some random errors, have been used to demonstrate the reliability of the algorithms to determine the interval velocities and thicknesses of various layers. The method has also been tested on two field examples along two deep seismic sounding (DSS) profiles with well identified wide-angle reflection travel times, which illustrates the practical feasibility of the proposed method.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00876497
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  • 100
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    Modeling the seismic source and tsunami generation of the December 12, 1992 Flores Island, Indonesia, earthquake (1995)
    Springer
    Pure and applied geophysics 144 (1995), S. 537-554 
    Details
    ISSN: 1420-9136
    Keywords: Earthquake source ; body waves ; moment tensor ; tsunami modeling ; submarine slumps ; Indonesia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract On December 12, 1992 a large earthquake (M s 7.5) occurred just north of Flores Island, Indonesia which, along with the tsunami it generated, killed more than 2,000 people. In this study, teleseismicP andSH waves, as well asPP waves from distances up to 123°, are inverted for the orientations and time histories of multiple point sources. By repeating the inversion for reasonable values of depth, time separation and spatial separation, a 2-fault model is developed. Next, the vertical deformation of the seafloor is estimated from this fault model. Using a detailed bathymetric model, linear and nonlinear tsunami propagation models are tested. The data consist of a single tide gauge record at Palopo (650 km to the north), as well as tsunami runup height measurements from Flores Island and nearby islands. Assuming a tsunami runup amplification factor of two, the two-fault model explains the tide gauge record and the tsunami runup heights on most of Flores Island. It cannot, however, explain the large tsunami runup heights observed near Leworahang (on Hading Bay) and Riangkroko (on the northeast peninsula). Massive coastal slumping was observed at both of these locations. A final model, which in addition to the two faults, includes point sources of large vertical displacement at these two locations explains the observations quite well.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00874382
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