ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Geological record and reconstruction of the late Pliocene impact of the Eltanin asteroid in the Southern Ocean (1997)
    [s.l.] : Macmillan Magazines Ltd.
    Nature 390 (1997), S. 357-363 
    Details
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] In 1995, an expedition on board the research vessel FS Polarstern explored the impact site of the Eltanin asteroid in the Southern Ocean, the only known asteroidimpact into a deep ocean basin. Analyses of the geological record of the impact region place the event in the late Pliocene ...
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1038/37044
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    The Equatorial Atlantic Mid-Ocean Channel: An Ultra High-Resolution Image of Its Burial History Based on TOPAS Profiles (1997)
    Springer
    Marine geophysical researches 19 (1997), S. 115-135 
    Details
    ISSN: 1573-0581
    Keywords: Mid-ocean channels ; Equatorial Atlantic ; Parametric echosounder sedimentary infilling
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract Multibeam bathymetric and ultra high-resolution seismic data reveal that the distal course of the Equatorial Atlantic Mid-Ocean Channel (EAMOC) extends further east and south than was previously known, and is controlled by the presence of morphologic highs related to the Fernando de Noronha Fracture Zone. Distal course of the EAMOC is buried by sediments, and does not have bathymetric expression on the seafloor. The channel fill consists of three seismic sequences, suggesting that the recent geological evolution of the channel is composed of successive phases of decreasing sedimentary activity that finally resulted in its complete burial. Tectonic and volcanic activity related to the Fernando de Noronha Fracture Zone and Ridge, together with the effect of strong pulses of the Antarctic bottom water current during the upper Pliocene are suggested to have contributed to the progressive burial and the final abandonment of the EAMOC.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1004273902719
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    facet.materialart.
    Unknown
    A geophysical strategy for measuring the thickness of the critical zone developed over basalt lavas (2015)
    Geological Society of America (GSA)
    In: Geosphere
    Details
    Publication Date: 2015-03-31
    Description: Estimates of the thickness variation in lateritic weathering profiles (LWPs) are important in tropical areas underlain by young basalt lavas like those found in Hawaii. Seismic shear-wave velocity data were obtained by a new application of multichannel analysis of surface waves (MASW) to map variations in the LWP and to derive the downward rate of advance of the weathering front in basaltic lavas. The MASW technique proved highly capable of imaging the internal structure and base of the critical zone, as confirmed by borehole data and direct field measurements. Profile thickness thus obtained, rapidly and without drilling, has applications to engineering and geochemical studies. The rate of advance of the weathering front derived from MASW in Oahu ranged from 0.010 m/ka to 0.026 m/ka in mesic zones (~1500 mm/a rainfall), whereas an area with ~800 mm/a revealed rates from 0.005 m/ka to 0.011 m/ka. These rates are comparable to those derived from recent solute-based mass balance studies of ground and surface water. Conventional P-wave seismic reflection did not perform as well for detecting boundaries due to a gradational seismic velocity structure within the weathering profile. Shear-wave velocity models showed internal variations that may be caused by textural differences in parental lava flows. Limitations in imaging depth were overcome by innovative experiment designs. Increasing source-receiver offsets and merging surface-wave dispersion curves allowed for a more objective derivation of velocity-frequency relations. Further improvements were made from a recently developed form of the combined active and passive source technique. These advances allowed for more detailed and deeper imaging of the subsurface with greater confidence. Velocity models derived from MASW can thus describe the LWP in terms of depth and variability in stiffness.
    Electronic ISSN: 1553-040X
    Topics: Geosciences
    Published by Geological Society of America (GSA)
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 4
    facet.materialart.
    Unknown
    Waves and stimulus-modulated dynamics in an oscillating olfactory network. (1994)
    National Academy of Sciences
    Details
    Publication Date: 1994-01-18
    Print ISSN: 0027-8424
    Electronic ISSN: 1091-6490
    Topics: Biology , Medicine , Natural Sciences in General
    Published by National Academy of Sciences
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 5
    facet.materialart.
    Unknown
    Evaporite evidence of a mid-Holocene (c. 4550-4400 cal. yr BP) aridity crisis in southwestern Europe and palaeoenvironmental consequences (2014)
    Sage
    In: Holocene
    Details
    Publication Date: 2014-03-12
    Description: Sedimentological evidence for an abrupt dry spell in south-eastern Spain during the middle Holocene, from c. 4906 to 4384 cal. yr BP, is presented. This phase was determined primarily from halite beds deposited between muddy slimes in a lagoon system of Puerto de Mazarrón (Murcia province) with a peak phase from c . 4550 to 4400 cal. yr BP. A multi-core, multi-proxy study of 20 geotechnical drills was made in the lagoon basin to identify the main sedimentary episodes and depositional environments. The results suggest that this halite bed, more than 80 cm thick, was conditioned by climate change and was accompanied by a generalized drying-out of the basin. Halite precipitation was linked with palaeoecological changes, including forest and mesophyte depletions and increasing cover and diversity of xerophytic plant species. Archaeological evidence indicates a demise of the population at this period probably due to resource exhaustion. An overall picture of the biostratigraphy and palaeoclimates of the region is given in a broader geographical context.
    Print ISSN: 0959-6836
    Electronic ISSN: 1477-0911
    Topics: Geography , Geosciences
    Published by Sage
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 6
    facet.materialart.
    Unknown
    Fire effects and ecological recovery pathways of Tropical Montane Cloud Forests along a time chronosequence (2017)
    Wiley
    Details
    Publication Date: 2017-10-29
    Description: Tropical montane cloud forests (TMCFs) harbour high levels of biodiversity and large carbon stocks. Their location at high elevations make them especially sensitive to climate change, because a warming climate is enhancing upslope species migration, but human disturbance (especially fire) may in many cases be pushing the treeline downslope. TMCFs are increasingly being affected by fire, and the long-term effects of fire are still unknown. Here we present a 28-years chronosequence to assess the effects of fire and recovery pathways of burned TMCFs, with a detailed analysis of carbon stocks, forest structure and diversity. We assessed rates of change of carbon (C) stock pools, forest structure, and tree size distribution pathways and tested several hypotheses regarding metabolic scaling theory (MST), C recovery and biodiversity. We found four different C stock recovery pathways depending on the selected C pool and time since last fire, with a recovery of total C stocks but not of aboveground C stocks. In terms of forest structure, there was an increase in the number of small stems in the burned forests up to 5-9 years after fire because of regeneration patterns, but no differences on larger trees between burned and unburned plots in the long term. In support of MST, after fire, forest structure appears to approximate steady state size distribution in less than 30 years. However, our results also provide new evidence that the species recovery of TMCF after fire is idiosyncratic and follows multiple pathways. While fire increased species richness it also enhanced species dissimilarity with geographical distance. This is the first study to report a long-term chronosequence of recovery pathways to fire suggesting faster recovery rates than previously reported, but at the expense of biodiversity and aboveground C stocks. This article is protected by copyright. All rights reserved.
    Print ISSN: 1354-1013
    Electronic ISSN: 1365-2486
    Topics: Biology , Energy, Environment Protection, Nuclear Power Engineering , Geography
    Published by Wiley
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 7
    facet.materialart.
    Unknown
    Diatom fluxes in the NW Mediterranean: evidence from a 12-year sediment trap record and surficial sediments (2013)
    Oxford University Press
    Details
    Publication Date: 2013-08-28
    Description: We examined the total diatom flux and species composition, total coccolith flux and total mass flux collected with a sediment trap between October 1993 and January 2006 in the northeastern entrance of the Gulf of Lions (North Western Mediterranean). The average daily diatom and coccolith fluxes (3 x 10 7 valves m 2 d –1 and 6.1 x 10 8 coccoliths m 2 day –1 , respectively) are comparable in magnitude with previously reported data sets in other high productivity areas of the Western Mediterranean. The temporal particle flux pattern reflected the variations in surface oceanographic conditions and primary productivity, which showed strong annual cycling. Highest diatom, coccolith and total mass fluxes always occurred during the winter–spring transition, while minima were observed during summer. Changes in the diverse diatom communities reflected the water column conditions throughout the record. The intensity of the diatom winter–spring blooms seemed to be enhanced in those years with intense and cold winds during winter, whereas years with low winter wind stress were liable to be less productive for diatoms. Coccolith fluxes exhibited a more stable interannual pattern than diatom fluxes. Significant discrepancies were found between the sediment trap and surficial sediment diatom assemblages.
    Print ISSN: 0142-7873
    Electronic ISSN: 1464-3774
    Topics: Biology
    Published by Oxford University Press
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 8
    facet.materialart.
    Unknown
    High-resolution productivity record and reconstruction of ENSO dynamics during the Holocene in the Eastern Equatorial Pacific using coccolithophores (2014)
    Sage
    In: Holocene
    Details
    Publication Date: 2014-01-21
    Description: We provide high-resolution paleoproductivity data for the Holocene in the Eastern Equatorial Pacific (EEP). We describe the coccolithophore assemblages at Ocean Drilling Program (ODP) Site 1240 located in the Panama basin. Coccolithophore assemblages are proposed as a productivity proxy and nutricline position for the tropical Pacific Ocean. Our proxies can be used as a tool to reconstruct the El Niño-Southern Oscillation (ENSO), the main factor controlling the climate variability in the EEP. The equatorial upwelling intensity and the influence of waters with a Sub-Antarctic origin have controlled the productivity and the phytoplankton composition during the Holocene, and this has been strongly controlled by ENSO dynamics and, as our data suggest, by Southern Hemisphere ocean dynamics. Our results reveal a clear prevalence of dominant La Niña-like conditions during the early Holocene, with an intense upwelling and high primary productivity conditions in the EEP. La Niña-like conditions prevailed during the middle Holocene, although important fluctuations were observed in paleoproductivity, and some periods with a low primary productivity were recognizable (between 8.2 and 8 kyr and around 7 and 6.5 kyr), indicating a weakened upwelling stage, as occurs during El Niño events. A strong decrease in paleoproductivity occurred between 5 and 4.3 kyr, suggesting a relevant shift toward dominant El Niño-like conditions, with an increase in the stratification of the water column. An alternation between El Niño-like and La Niña-like dominant conditions occurred during the late Holocene, characterized by a clear trend toward prevailing El Niño-like conditions, with a low primary productivity.
    Print ISSN: 0959-6836
    Electronic ISSN: 1477-0911
    Topics: Geography , Geosciences
    Published by Sage
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 9
    facet.materialart.
    Unknown
    Structural evidence of enhanced active subsidence at the bottom of a maar: Rincon de Parangueo, Mexico (2016)
    Geological Society (of London)
    Details
    Publication Date: 2016-10-08
    Description: Rincón de Parangueo is a Quaternary maar that has been recently desiccated. The crater was partially occupied by a soda lake, and near the shoreline microbialites have formed. Evaporites (mainly trona and halite) precipitated as the water level dropped. Active subsidence of the lake floor ( c. 24 m since 1980) produced countless structures close to the lakeshore, where deformation is extensional. Closer to the depocentre, in the western half of the basin, gliding/spreading produced folds and mud-injection domes. The most remarkable structure throughout the basin is a monocline that forms a ring-like, nearly continuous scarp, approximately 15 m high, which in the eastern half of the basin was produced as a fault-propagation fold developed above the buried diatreme–country rock boundary. A more diffuse (wider) monocline, locally associated with compressive structures, occurs in the western half of the basin. These structures are interpreted as having developed above a gently inclined, irregular lake sediment–country rock (andesite) interphase. The monocline was modified by high-angle extensional faults/fractures with large heaves/apertures. In the eastern half of the basin, there is a second (outer) scarp, approximately 13 m high, formed by a high-angle, listric, normal fault. Rollover antiforms occur in the hanging wall of this structure. Rincón is an example of centripetal gravitational gliding/spreading.
    Print ISSN: 0305-8719
    Electronic ISSN: 2041-4927
    Topics: Geosciences
    Published by Geological Society (of London)
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 10
    facet.materialart.
    Unknown
    Atmospheric patterns driving Holocene productivity in the Alboran Sea (Western Mediterranean): A multiproxy approach (2015)
    Sage
    In: Holocene
    Details
    Publication Date: 2015-03-03
    Description: High-resolution paleoproductivity variations have been reconstructed in a productive cell in the Alboran Sea for the Holocene. Fossil coccolithophore assemblages have been studied along with the $${\mathrm{U}}_{37}^{{\mathrm{K}}^{\prime }}$$ -estimated sea-surface temperature (SST) and other paleoenvironmental proxies. The appearance of this cell is suggested at 7.7 ka cal. BP and was linked to the establishment of the western anti-cyclonic gyre. From that time until the present, the nannofossil accumulation rate of Florisphaera profunda has revealed successive episodes of weakening and strengthening of upwelling conditions in the Alboran Sea that have been simultaneous to changes in Western Mediterranean Deep Water (WMDW) formation in the Gulf of Lions. A two-phase scenario operating at millennial–centennial time scale is proposed to explain this climatic and oceanographic variability: (1) coeval with more arid climate conditions, weaker northerlies or north-westerlies blowing over the Gulf of Lions would have triggered a slackening of WMDW formation. This together with a minor Atlantic Jet (AJ) inflowing into the Alboran Sea would have led to less vertical mixing and, hence, a more stable water column in the study area; (2) wetter climate conditions would have prevailed in the region, while stronger northerlies or north-westerlies would have enabled WMDW reinforcement in the Gulf of Lions simultaneous to an intensification of the AJ that migrated southward. This would have increased vertical mixing, intensifying upwelling conditions in the study area. Here, the winter North Atlantic Oscillation (NAO) is considered to be an important forcing mechanism for this variability, influencing WMDW formation, which in turn has been linked to short-term productivity variations during the last 7.7 ka in the Alboran Sea.
    Print ISSN: 0959-6836
    Electronic ISSN: 1477-0911
    Topics: Geography , Geosciences
    Published by Sage
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...