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
Filter
  • Blackwell Publishing Ltd
  • Cambridge University Press
  • 2015-2019  (2,208)
  • 1950-1954
  • 2018  (2,208)
Collection
Keywords
Publisher
Years
  • 2015-2019  (2,208)
  • 1950-1954
Year
  • 1
    facet.materialart.
    Unknown
    SHMIP The subglacial hydrology model intercomparison Project (2018)
    Cambridge University Press
    In:  EPIC3Journal of Glaciology, Cambridge University Press, 64, pp. 897-916, ISSN: 0022-1430
    Details
    Publication Date: 2019-01-02
    Description: Subglacial hydrology plays a key role in many glaciological processes, including ice dynamics via the modulation of basal sliding. Owing to the lack of an overarching theory, however, a variety of model approximations exist to represent the subglacial drainage system. The Subglacial Hydrology Model Intercomparison Project (SHMIP) provides a set of synthetic experiments to compare existing and future models. We present the results from 13 participating models with a focus on effective pressure and discharge. For many applications (e.g. steady states and annual variations, low input scenarios) a simple model, such as an inefficient-system-only model, a flowline or lumped model, or a porous-layer model provides results comparable to those of more complex models. However, when studying short term (e.g. diurnal) variations of the water pressure, the use of a two-dimensional model incorporating physical representations of both efficient and inefficient drainage systems yields results that are significantly different from those of simpler models and should be preferentially applied. The results also emphasise the role of water storage in the response of water pressure to transient recharge. Finally, we find that the localisation of moulins has a limited impact except in regions of sparse moulin density.
    Repository Name: EPIC Alfred Wegener Institut
    Type: Article , isiRev
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 2
    facet.materialart.
    Unknown
    Prototype wireless sensors for monitoring subsurface processes in snow and firn (2018)
    Cambridge University Press
    In:  EPIC3Journal of Glaciology, Cambridge University Press, 64, pp. 887-896, ISSN: 0022-1430
    Details
    Publication Date: 2019-01-02
    Description: The detection and monitoring of meltwater within firn presents a significant monitoring challenge. We explore the potential of small wireless sensors (ETracer+, ET+) to measure temperature, pressure, electrical conductivity and thus the presence or absence of meltwater within firn, through tests in the dry snow zone at the East Greenland Ice Core Project site. The tested sensor platforms are small, robust and low cost, and communicate data via a VHF radio link to surface receivers. The sensors were deployed in low-temperature firn at the centre and shear margins of an ice stream for 4 weeks, and a ‘bucket experiment’ was used to test the detection of water within otherwise dry firn. The tests showed the ET+ could log subsurface temperatures and transmit the recorded data through up to 150 m dry firn. Two VHF receivers were tested: an autonomous phase-sensitive radio-echo sounder (ApRES) and a WinRadio. The ApRES can combine high-resolution imaging of the firn layers (by radio-echo sounding) with in situ measurements from the sensors, to build up a high spatial and temporal resolution picture of the subsurface. These results indicate that wireless sensors have great potential for long-term monitoring of firn processes.
    Repository Name: EPIC Alfred Wegener Institut
    Type: Article , isiRev
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 3
    facet.materialart.
    Unknown
    Ocean-excited plate waves in the Ross and Pine Island Glacier ice shelves (2018)
    Cambridge University Press
    Details
    Publication Date: 2022-05-25
    Description: © The Author(s), 2018. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Journal of Glaciology 64 (2018): 730-744, doi:10.1017/jog.2018.66.
    Description: Ice shelves play an important role in buttressing land ice from reaching the sea, thus restraining the rate of grounded ice loss. Long-period gravity-wave impacts excite vibrations in ice shelves that can expand pre-existing fractures and trigger iceberg calving. To investigate the spatial amplitude variability and propagation characteristics of these vibrations, a 34-station broadband seismic array was deployed on the Ross Ice Shelf (RIS) from November 2014 to November 2016. Two types of ice-shelf plate waves were identified with beamforming: flexural-gravity waves and extensional Lamb waves. Below 20 mHz, flexural-gravity waves dominate coherent signals across the array and propagate landward from the ice front at close to shallow-water gravity-wave speeds (~70 m s−1). In the 20–100 mHz band, extensional Lamb waves dominate and propagate at phase speeds ~3 km s−1. Flexural-gravity and extensional Lamb waves were also observed by a 5-station broadband seismic array deployed on the Pine Island Glacier (PIG) ice shelf from January 2012 to December 2013, with flexural wave energy, also detected at the PIG in the 20–100 mHz band. Considering the ubiquitous presence of storm activity in the Southern Ocean and the similar observations at both the RIS and the PIG ice shelves, it is likely that most, if not all, West Antarctic ice shelves are subjected to similar gravity-wave excitation.
    Description: Bromirski, Gerstoft, Chen and Diez were supported by NSF grant PLR 1246151. Stephen was supported by NSF grant PLR-1246416. Wiens, Aster and Nyblade were supported under NSF grants PLR-1142518, 1141916 and 1142126, respectively.
    Keywords: Beamforming ; Cross-correlation ; Flexural-gravity waves ; Ice/ocean interactions ; Ice shelves ; Particle motion ; Plate waves
    Repository Name: Woods Hole Open Access Server
    Type: Article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 4
    facet.materialart.
    Unknown
    Using 10Be exposure dating to constrain glacial advances during the late glacial and Holocene on Mount Xuebaoding, eastern Tibetan Plateau (2018)
    Cambridge University Press
    Details
    Publication Date: 2018
    Description: 〈div data-abstract-type="normal"〉〈p〉Moraines preserved around Mount Xuebaoding (5588 m above sea level) on the eastern margin of the Tibetan Plateau, represent past glacial activity in this area. The chronology of these moraines was established using 〈span〉10〈/span〉Be exposure dating. The dating results revealed multiple glacial events prior to the late glacial (〈span〉〉〈/span〉14.1±2.2 ka), the late glacial (15.6±1.6 to 11.2±3.0 ka), the early-middle Holocene (9.1±0.9 to 6.7±0.7 ka), and the Neoglacial periods (2.5±0.5 to 1.5±0.1 ka). These glacial stages are consistent with the recalculated ages from surrounding areas throughout the Indian and East Asian monsoon-influenced region on the eastern Tibetan Plateau. Comparing with other paleoclimate indexes, we suggest that the late glacial event was mainly driven by low temperature, the early–middle Holocene event by high precipitation, and the late Holocene/Neoglacial event by low temperature.〈/p〉〈/div〉
    Print ISSN: 0033-5894
    Electronic ISSN: 1096-0287
    Topics: Geography , Geosciences
    Published by Cambridge University Press
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 5
    facet.materialart.
    Unknown
    Loess–paleosol carbonate clumped isotope record of late Pleistocene–Holocene climate change in the Palouse region, Washington State, USA (2018)
    Cambridge University Press
    Details
    Publication Date: 2018
    Description: 〈div data-abstract-type="normal"〉〈p〉The Channeled Scabland–Palouse region of the Pacific Northwest (PNW) of the United States preserves geomorphic and pedosedimentary records that inform understanding of late Pleistocene–Holocene paleoclimate change in a region proximal to the last glacial period Cordilleran Ice Sheet. We present a clumped (Δ〈span〉47〈/span〉) and conventional (δ〈span〉18〈/span〉O, δ〈span〉13〈/span〉C) isotopic study of Palouse loess–paleosol carbonates in combination with carbonate radiocarbon (〈span〉14〈/span〉C) dating to provide new measures of regional late–last glacial (~31–20 cal ka BP) and Holocene soil conditions. Average clumped isotope temperatures (T(Δ〈span〉47〈/span〉)) for last glacial Palouse loess–paleosol carbonates (9±4°C) are significantly lower than those for Holocene-aged carbonates (T(Δ〈span〉47〈/span〉)=18±2°C) in study sections. Calculated soil water δ〈span〉18〈/span〉O〈span〉VSMOW〈/span〉 values (−16±2‰) for last glacial carbonates are also offset relative to those for Holocene-aged samples (−11±1‰), whereas calculated soil CO〈span〉2〈/span〉 δ〈span〉13〈/span〉C〈span〉VPDB〈/span〉 values are similar for the Holocene (−16.9±0.2‰) and late–last glacial (−16.7±1.1‰) periods. Together, these paleoclimate metrics indicate late–last glacial conditions of pedogenic carbonate formation in the C〈span〉3〈/span〉 grassland soils of the Palouse were measurably colder (9±5°C) than during the Holocene and potentially reflect a more arid last glacial paleoclimate across the Palouse, findings in agreement with previous proxy studies and climate model simulations for the region.〈/p〉〈/div〉
    Print ISSN: 0033-5894
    Electronic ISSN: 1096-0287
    Topics: Geography , Geosciences
    Published by Cambridge University Press
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 6
    facet.materialart.
    Unknown
    Millennial-scale Asian monsoon variability during the late Marine Isotope Stage 6 from Hulu Cave, China (2018)
    Cambridge University Press
    Details
    Publication Date: 2018
    Description: 〈div data-abstract-type="normal"〉〈p〉A precisely 〈span〉230〈/span〉Th-dated stalagmite δ〈span〉13〈/span〉C profile from Hulu Cave, China, is presented to characterize the frequency and pattern of millennial-scale Asian monsoon (AM) variability from 160.6 to 132.5 ka. Evidence for an antiphased relationship of the δ〈span〉13〈/span〉C and δ〈span〉18〈/span〉O on the millennial scale suggests that the δ〈span〉13〈/span〉C is indicative of the local hydrological cycle associated with changes in AM strength. Owing to the δ〈span〉13〈/span〉C responding to AM changes more sensitively than the δ〈span〉18〈/span〉O, we could identify 15 strong AM events that correlate to cold intervals recorded in Antarctic ice cores within 〈span〉230〈/span〉Th dating uncertainty. This result supports a dynamic link of AM strength and southern hemispheric climates via the cross-equatorial airflows. Power spectrum analysis shows a predominant periodicity of 1.5–2.5 ka for the δ〈span〉13〈/span〉C profile, similar to the Dansgaard-Oeschger frequency during the last glacial period. Moreover, the AM events are characterized by rapid transitions at the onset, suggesting that the observed millennial-scale AM variability is likely forced by northern high-latitude climates via north–south shifts of the Intertropical Convergence Zone associated with the bipolar seesaw mechanism. As evidence for a common mechanism for ice age terminations, a strong AM event (~134 ka) surrounding Termination II is analogous to the Bølling-Allerød warming interval.〈/p〉〈/div〉
    Print ISSN: 0033-5894
    Electronic ISSN: 1096-0287
    Topics: Geography , Geosciences
    Published by Cambridge University Press
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 7
    facet.materialart.
    Unknown
    Drainage system reorganization and late Quaternary tectonic deformation along the southern Dead Sea Transform (2018)
    Cambridge University Press
    Details
    Publication Date: 2018
    Description: 〈div data-abstract-type="normal"〉〈p〉The Dead Sea Transform (DST) accounts for ~105 km of left-lateral slip between the Arabian plate and the Sinai subplate since the Miocene. Paleoseismic studies along the Arava Valley segment of the DST suggest that late Quaternary deformation has been primarily concentrated along the axis of the transform valley. Here, we examine late Quaternary changes in drainage system characteristics and attribute them to recent tectonic deformation in this region. Field-based geomorphic mapping, topographic cross sections, and optically stimulated luminescence (OSL) dating of fluvial deposits were used to map and date recent changes in the fluvial characteristics of catchments along the western margin of the southern Arava. Our results reveal coeval migration of channels, consistent with tectonically induced surface tilting caused by north–south compressional deformation along the western margin of the transform valley. OSL dating indicates this tilting was initiated in the late Pleistocene and continued at least into the mid-Holocene. The late Quaternary tectonic deformation along the southern Arava segment of the DST is distributed across a wider zone than previously considered and extends out to the margins of the transform valley. We associate the inferred wider deformation zone to possible changes in the geometry of motion along the DST.〈/p〉〈/div〉
    Print ISSN: 0033-5894
    Electronic ISSN: 1096-0287
    Topics: Geography , Geosciences
    Published by Cambridge University Press
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 8
    facet.materialart.
    Unknown
    A continuous 4000-year lake-level record of Owens Lake, south-central Sierra Nevada, California, USA (2018)
    Cambridge University Press
    Details
    Publication Date: 2018
    Description: 〈div data-abstract-type="normal"〉〈p〉Reconstruction of lake-level fluctuations from landform and outcrop evidence typically involves characterizing periods with relative high stands. We developed a new approach to provide water-level estimates in the absence of shoreline evidence for Owens Lake in eastern California by integrating landform, outcrop, and existing lake-core data with wind-wave and sediment entrainment modeling of lake-core sedimentology. We also refined the late Holocene lake-level history of Owens Lake by dating four previously undated shoreline features above the water level (1096.4 m) in AD 1872. The new ages coincide with wetter and cooler climate during the Neopluvial (~3.6 ka), Medieval Pluvial (~0.8 ka), and Little Ice Age (~0.35 ka). Dates from stumps below 1096 m also indicate two periods of low stands at ~0.89 and 0.67 ka during the Medieval Climatic Anomaly. The timing of modeled water levels associated with 22 mud and sand units in lake cores agree well with shoreline records of Owens Lake and nearby Mono Lake, as well as with proxy evidence for relatively wet and dry periods from tree-ring and glacial records within the watershed. Our integrated analysis provides a continuous 4000-yr lake-level record showing the timing, duration, and magnitude of hydroclimate variability along the south-central Sierra Nevada.〈/p〉〈/div〉
    Print ISSN: 0033-5894
    Electronic ISSN: 1096-0287
    Topics: Geography , Geosciences
    Published by Cambridge University Press
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 9
    facet.materialart.
    Unknown
    Megalakes in the Sahara? A Review – ADDENDUM (2018)
    Cambridge University Press
    Details
    Publication Date: 2018
    Print ISSN: 0033-5894
    Electronic ISSN: 1096-0287
    Topics: Geography , Geosciences
    Published by Cambridge University Press
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 10
    facet.materialart.
    Unknown
    Drainage system reorganization and late Quaternary tectonic deformation along the southern Dead Sea Transform – ADDENDUM (2018)
    Cambridge University Press
    Details
    Publication Date: 2018
    Print ISSN: 0033-5894
    Electronic ISSN: 1096-0287
    Topics: Geography , Geosciences
    Published by Cambridge University Press
    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...