ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
Filter
  • Elsevier  (5,804,775)
  • Oxford University Press  (428,981)
  • Blackwell Publishing Ltd  (182,058)
Collection
Publisher
Language
Years
  • 1
    Publication Date: 2024-06-13
    Description: Southern hemisphere humpback whale (Megaptera novaeangliae, SHHW) breeding populations follow a high-fidelity Antarctic krill (Euphausia superba) diet while feeding in distinct sectors of the Southern Ocean. Their capital breeding life history requires predictable ecosystem productivity to fuel migration and migration-related behaviours. It is therefore postulated that populations feeding in areas subject to the strongest climate change impacts are more likely to show the first signs of a departure from a high-fidelity krill diet. We tested this hypothesis by investigating blubber fatty acid profiles and skin stable isotopes obtained from five SHHW populations in 2019, and comparing them to Antarctic krill stable isotopes sampled in three SHHW feeding areas in the Southern Ocean in 2019. Fatty acid profiles and δ13C and δ15N varied significantly among all five populations, however, calculated trophic positions did not (2.7 to 3.1). Similarly, fatty acid ratios, 16:1ω7c/16:0 and 20:5ω3/22:6ω3 were above 1, showing that whales from all five populations are secondary heterotrophs following an omnivorous diet with a diatom-origin. Thus, evidence for a potential departure from a high-fidelity Antarctic krill diet was not seen in any population. δ13C of all populations were similar to δ13C of krill sampled in productive upwelling areas or the marginal sea-ice zone. Consistency in trophic position and diet origin but significant fatty acid and stable isotope differences demonstrate that the observed variability arises at lower trophic levels. Our results indicate that, at present, there is no evidence of a divergence from a high-fidelity krill diet. Nevertheless, the characteristic isotopic signal of whales feeding in productive upwelling areas, or in the marginal sea-ice zone, implies that future cryosphere reductions could impact their feeding ecology.
    Repository Name: EPIC Alfred Wegener Institut
    Type: Article , isiRev
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Publication Date: 2024-06-13
    Description: Volcanic rocks are the prominent host rocks in geothermal and volcanic systems in general, displaying heterogeneity. Although various external factors such as temperature, pressure, time, fluid chemistry, and subsurface geology have been thoroughly researched regarding the source of hydrothermal minerals in geothermal fields, the effect of hydrothermal alteration on volcanic hosts is still controversial in the literature. This review compiles data on the physical and mechanical properties of the host rocks composing volcanic environments exhibiting hydrothermal alteration or remaining unaltered. The considered data is originated from hydrothermal areas from Kuril-Kamchatka (Russia), Los Humeros (Mexico), Ngatamaraki, Rotokawa, Kawerau and Ohakuri geothermal fields and Mt. Ruapehu, Mt. Taranaki, and Whakaari volcanoes (New Zealand), Solfatara (Italy), Reykjanes, Nesjavellir, and Theistarereykir geothermal fields (Iceland), La Soufrière de Guadeloupe (Caribbean) volcano, and Merapi volcano (Indonesia). Analysis of average values displayed in several graphical representations and correlations finds that dense rocks (such as lavas and intrusive rocks) exhibit greater competence and lower porosity than fragmental rocks. However, altered dense rocks display greater variability in mechanical properties compared to pyroclastic rocks, primarily influenced by mineral dissolution leading to rock weakening. Exceptions occur for high-temperature hydrothermal alteration, such as advanced silicification and propylitic alteration, with the latter influenced by minor types of alteration. Fragmental rocks have diverse behaviour with the extent of hydrothermal alteration and welding/compaction. According to the compiled data, an overall strengthening of pyroclastic rocks develops as hydrothermal alteration increases, regardless of the type of hydrothermal alteration. The complexity of hydrothermal systems, the variability shown by different hydrothermal settings and histories in terms of temperature, fluid chemistry and secondary mineral assemblage, and the variety of rock materials with different microstructures contribute to moderate correlations between properties compared to those established in an unaltered state. However, the same trends (linear, nonlinear, positive, negative) are preserved along hydrothermal alteration. This review emphasizes the significance of the type and degree of hydrothermal alteration, along with the rock type and pre-existence of fractures, in shaping the development of alteration in volcanic environments and modifying the properties of host rocks. The relevance of the review relies on the fact that these properties are considered to enhance the productivity of geothermal fields and improve the assessment of volcanic hazards. Future research is expected to expand on this groundwork.
    Description: Published
    Description: 104754
    Description: OSV4: Preparazione alle crisi vulcaniche
    Description: JCR Journal
    Keywords: Hydrothermal alteration ; physical properties ; degree of hydrothermal alteration ; mechanical properties ; hydrothermal alteration facies ; intrusion-related geothermal systems ; 04.08. Volcanology
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Publication Date: 2024-06-13
    Description: Amplitude and phase scintillation indexes (S4 and SigmaPhi) provided by Ionospheric Scintillation Monitoring (ISM) receivers are the most used GNSS-based indicators of the signal fluctuations induced by the presence of ionospheric irregularities. These indexes are available only from ISM receivers which are not as abundant as other types of professional GNSS receivers, resulting in limited geographic distribution. This makes the scintillation indexes measurements rare and sparse compared to other types of ionospheric measurements available from GNSS receivers. Total Electron Content (TEC), on the other hand, is an ionospheric parameter available from a wide range of multi-frequency GNSS receivers. Many efforts have worked on establishing scintillation indicators based on TEC, and geodetic receivers in general, introducing various metrics, including the Rate of TEC change (ROT) and ROT Index (ROTI). However, a possible relationship between TEC and its variation, and the corresponding scintillation index that an Ionospheric Scintillation Monitor (ISM) receiver would estimate is not trivial. In principle, TEC can be retrieved from carrier phase measurements of the GNSS receiver, as . We investigate how to estimate SigmaPhi from time series of TEC and ROT measurements from an ISM in Ny-Ålesund (Svalbard) using Machine Learning (ML). To evaluate its usability to estimate SigmaPhi from geodetic receivers, the model is tested using TEC data provided by a quasi-co-located geodetic receiver belonging to the International GNSS Service (IGS) network. It is shown that the model performance when TEC from the IGS receiver is used gives comparable results to the model performance when TEC from the ISM receiver is utilised. The model's ability to infer the exact value of the scintillation index is bound to Mean Square Error (MSE) = 0.1 radians^2 when SigmaPhi 〈 0. 8 radians. For SigmaPhi 〉 0. 8 radians the MSE reaches 0.18 and 0.45 radians^2 in operative testing using ISM and IGS measurements, respectively. However, the model’s ability to detect phase scintillation from IGS TEC measurements is comparable to expert visual inspection. Such a model has potential in alerting against phase fluctuations resulting in enhanced SigmaPhi, especially in locations where ISM receivers are not available, but other types of dual-frequency GNSS receivers are present.
    Description: Published
    Description: 3753-3771
    Description: OSA3: Climatologia e meteorologia spaziale
    Description: JCR Journal
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Publication Date: 2024-06-13
    Description: Climate change affects human activities, including tourism across various sectors and time frames. The winter tourism industry, dependent on low temperatures, faces significant impacts. This paper reviews the implications of climate change on winter tourism, emphasising challenges for activities like skiing and snowboarding, which rely on consistent snowfall and low temperatures. As the climate changes, these once taken-for-granted conditions are no longer as commonplace. Through a comprehensive review supported by up-to-date satellite imagery, this paper presents evidence suggesting that the reliability of winter snow is decreasing, with findings revealing a progressive reduction in snow levels associated with temperature and precipitation changes in some regions. The analysis underscores the need for concerted efforts by stakeholders who must recognize the reality of diminishing snow availability and work towards understanding the specific changes in snow patterns. This should involve multi-risk and multi-instrument assessments, including ongoing satellite data monitoring to track snow cover changes. The practical implications for sports activities and the tourism industry reliant on snow involve addressing challenges by diversifying offerings. This includes developing alternative winter tourism activities less dependent on snow, such as winter hiking, nature walks, or cultural experiences.
    Description: Published
    Description: 120554
    Description: OSA2: Evoluzione climatica: effetti e loro mitigazione
    Description: JCR Journal
    Keywords: Climate change ; Adaptation ; Tourism losses ; Winter sport ; Multi-date satellite imagery ; 05.09. Miscellaneous
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    Publication Date: 2024-06-13
    Description: The topside ionosphere extends from the F2-layer peak, where the electron density reaches its absolute maximum in the ionosphere, to the overlying plasmasphere and magnetosphere. In the topside ionosphere, the electron density decreases with height with a vertical variation rate strongly dependent on height itself. The last version of the International Reference Ionosphere (IRI) model, i.e., IRI-2020, describes this complex behavior through four topside options based on different sub-models (i.e., options) developed from the 1970s to the present. All these options have in common the F2-layer peak as an anchor point, while they differ in their topside electron density profile and/or plasma effective scale height formulations. In this work, we perform a validation of the accuracy of the four IRI-2020 topside options based on the comparison against in-situ electron density observations by Gravity Recovery and Climate Experiment (GRACE), Ionospheric Connection Explorer (ICON), and Defense Meteorological Satellite Program (DMSP) F15 low-Earth-orbit satellites. Datasets used in this study encompass observations recorded from 1999 to 2022, covering different diurnal, seasonal, and solar activity conditions, on a global basis and for the height range 400–850 km above the ground. The nearly two solar cycles dataset facilitated the evaluation of IRI-2020 topside options ability to reproduce the spatial and time variations of the topside ionosphere for different solar activity conditions. The weaknesses and strengths of each IRI-2020 topside option are highlighted and discussed, and suggestions on how to improve the modeling of the challenging topside ionosphere region within the IRI model are provided for future reference.
    Description: In press
    Description: OSA3: Climatologia e meteorologia spaziale
    Description: JCR Journal
    Keywords: Topside ionosphere modeling ; International Reference Ionosphere (IRI) model ; In-situ electron density observations ; Low-Earth-Orbit satellites ; 01.02. Ionosphere
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Publication Date: 2024-06-13
    Description: The exchange of trace gases across the ocean/atmosphere interface, as well as the deposition of atmospheric pollutants and aerosols, are key processes linking the biogeochemical cycles and biological processes in the ocean with atmospheric chemistry and climate. Here we summarize our knowledge about the distributions of long-lived trace gases (CO2, CH4, N2O), short-lived trace gases, and pollutants (dimethyl sulfide (DMS), isoprene, halocarbons, NOx, SO2, O3, and others), and aerosols in the Indian Ocean. In general, dissolved trace gases show a pronounced temporal and spatial variability, which is caused by the variability of both physical processes (e.g., coastal upwelling) and biological productivity. The distributions of pollutants and aerosols and their depositions to the sea surface are mainly driven by the monsoon system and the variability of their land sources. Nitrogen and iron-containing aerosols can significantly affect biological production in the surface layer of the open Indian Ocean.
    Type: Book chapter , PeerReviewed
    Format: text
    Format: slideshow
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    Publication Date: 2024-06-13
    Description: Neomphaloidean gastropods are endemic to chemosynthesis-based ecosystems ranging from hot vents to organic falls, and their diversity and evolutionary history remain poorly understood. In the southwestern Pacific, deep-sea hydrothermal vents on back-arc basins and volcanic arcs are found in three geographically secluded regions: a western region around Manus Basin, an eastern region around North Fiji and Lau Basins, and the intermediate Woodlark Basin where active venting was confirmed only recently, on the 2019 R/V L’Atalante CHUBACARC expedition. Although various lineages of neomphaloidean snails have been detected, typically restricted to one of the three regions, some of these have remained without names. Here, we use integrative taxonomy to describe three of these species: the neomphalid Symmetromphalus mithril sp. nov. from Woodlark Basin and the peltospirids Symmetriapelta becki sp. nov. from the eastern region and Symmetriapelta radiata sp. nov. from Woodlark Basin. A combination of shell sculpture and radular characters allow the morphological separation of these new species from their described congeners. A molecular phylogeny reconstructed from 570 bp of the mitochondrial cytochrome c oxidase subunit I gene confirmed the placement of the three new species in their respective genera and the superfamily Neomphaloidea. The finding of these new gastropods, particularly the ones from the Woodlark Basin, provides insights and implications on the historical role of Woodlark as a dispersing centre, in addition to highlighting the uniqueness of the Woodlark faunal community.
    Type: Article , PeerReviewed
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    Publication Date: 2024-06-13
    Description: The Indian Ocean is an important conduit for the exchange of physical and biogeochemical properties through many distinct interbasin oceanic connections. The Indonesian archipelago provides a gappy pathway for warm tropical waters to enter the Indian Ocean from the Pacific. South of Australia, a complex circulation transports cooler subtropical waters from the Pacific while Indian Ocean waters from within the Leeuwin Current feed a series of currents along the southern Australian continental margin. Southern Ocean waters source both the deep and shallow overturning circulations into the Indian Ocean. The westward leakage of eddies spawned from the Agulhas Current off South Africa returns warm and salty Indian Ocean waters into the Atlantic and plays a significant role in the upper branch of the global meridional overturning circulation. This chapter discusses these pathways and highlights how they change with time and influence the circulation and properties of the Indian and global oceans.
    Type: Book chapter , PeerReviewed
    Format: text
    Format: slideshow
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    Publication Date: 2024-06-13
    Type: Article , PeerReviewed , info:eu-repo/semantics/article
    Format: text
    Format: archive
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    Publication Date: 2024-06-12
    Description: The Campanian Volcanic Zone (CVZ) comprises multiple active volcanoes and includes the highly productive Campi Flegrei and Ischia caldera systems. These caldera volcanoes have produced probably the largest eruptions in Europe in the past 200 ka, such as the Monte Epomeo Green Tuff (MEGT; Ischia) at ca. 56 ka and the Campanian Ignimbrite (CI; Campi Flegrei) at ca. 40 ka, which form widespread isochrons across the Mediterranean region. These closely-spaced volcanic centres erupt phonolitic to trachytic glass compositions that are similar, and thus it can be challenging to correlate tephra deposits to specific volcanic sources. Here we present a detailed tephrostratigraphy for pre-CI eruption activity using the units preserved within a sequence at the coastal Acquamorta outcrop, on the western side of the CI caldera rim. Both the MEGT and CI units are present in the section, and they bracket twelve eruption units that were logged and sampled. New major and trace element glass chemistry data have been acquired for these Acquamorta tephra deposits. Three eruption deposits from Ischia and nine from Campi Flegrei are identified, which helps constrain the tempo of volcanic activity of these centres between the large caldera-forming eruptions. The three Ischia tephra deposits between the MEGT and the CI are indistinguishable based on both major and trace element glass chemistry and cannot be correlated to a specific or known eruption in this interval, such as the Schiappone tephra. The compositional variations between the Campi Flegrei eruptions reveal temporal shifts in the composition of the tephra deposits that reflect changes in the magmatic system prior to the CI eruption. These deposits indicate that there were at least nine eruptions at Campi Flegrei within 16 ka of the enormous CI eruption, and suggest that there was no significant period of repose before the caldera generating eruption.
    Description: Published
    Description: 107915
    Description: OSV2: Complessità dei processi vulcanici: approcci multidisciplinari e multiparametrici
    Description: JCR Journal
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...