ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

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
Collection
Language
  • 1
    Description / Table of Contents: The publication of this volume occurs at the one-hundredth anniversary of 1905, which has been called the annus mirabilus because it was the year of a number of enormous scientific advances. Among them are four papers by Albert Einstein explaining (among other things) Brownian motion, the photoelectric effect, the special theory of relativity, and the equation E = mc2. Also of significance in 1905 was the first application of another major advance in physics, which dramatically changed the fields of Earth and planetary science. In March of 1905 (and published the following year), Ernest Rutherford presented the following in the Silliman Lectures at Yale: "The helium observed in the radioactive minerals is almost certainly due to its production from the radium and other radioactive substances contained therein. If the rate of production of helium from known weights of the different radioelements were experimentally known, it should thus be possible to determine the interval required for the production of the amount of helium observed in radioactive minerals, or, in other words, to determine the age of the mineral." Rutherford E (1906) Radioactive Transformations. Charles Scriber's Sons, NY Thus radioisotopic geochronology was born, almost immediately shattering centuries of speculative conjectures and estimates and laying the foundation for establishment of the geologic timescale, the age of the Earth and meteorites, and a quantitative understanding of the rates of processes ranging from nebular condensation to Quaternary glaciations. There is an important subplot to the historical development of radioisotopic dating over the last hundred years, which, ironically, arises directly from the subsequent history of the U-He dating method Rutherford described in 1905. Almost as soon as radioisotopic dating was invented, it was recognized that the U-He [or later the (U-Th)/He method], provided ages that were often far younger than those allowed by stratigraphic correlations or other techniques such as U/Pb dating. Clearly, as R.J. Strutt noted in 1910, He ages only provided "minimum values, because helium leaks out from the mineral, to what extent it is impossible to say" (Strutt, 1910, Proc Roy Soc Lond, Ser A 84:379-388). For several decades most attention was diverted to U/Pb and other techniques better suited to measurement of crystallization ages and establishment of the geologic timescale. Gradually it became clear that other radioisotopic systems such as K/Ar and later fission-track also provided ages that were clearly younger than formation ages. In 1910 it may have been impossible to say the extent to which He (or most other elements) leaked out of minerals, but eventually a growing understanding of thermally-activated diffusion and annealing began to shed light on the significance of such ages. The recognition that some systems can provide cooling, rather than formation, ages, was gradual and diachronous across radioisotopic systems. Most of the heavy lifting in this regard was accomplished by researchers working on the interpretation of K/Ar and fission-track ages. Ironically, Rutherford¹s He-based radioisotopic system was one of the last to be quantitatively interpreted as a thermochronometer, and has been added to K/Ar (including 40Ar/39Ar) and fission-track methods as important for constraining the medium- to low-temperature thermal histories of rocks and minerals. Thermochronology has had a slow and sometimes fitful maturation from what were once troubling age discrepancies and poorly-understood open-system behaviors, into a powerful branch of geochronology applied by Earth scientists from diverse fields. Cooling ages, coupled with quantitative understanding of crystal-scale kinetic phenomena and crustal- or landscape-scale interpretational models now provide an enormous range of insights into tectonics, geomorphology, and subjects of other fields. At the same time, blossoming of lower temperature thermochronometric approaches has inspired new perspectives into the detailed behavior of higher temperature systems that previously may have been primarily used for establishing formation ages. Increased recognition of the importance of thermal histories, combined with improved analytical precision, has motivated progress in understanding the thermochronologic behavior of U/Pb, Sm/Nd, Lu/Hf, and other systems in a wide range of minerals, filling out the temperature range accessible by thermochronologic approaches. Thus the maturation of low- and medium-temperature thermochronology has led to a fuller understanding of the significance of radioisotopic ages in general, and to one degree or another has permeated most of geochronology. Except in rare cases, the goal of thermochronology is not thermal histories themselves, but rather the geologic processes responsible for them. Thermochronometers are now routinely used for quantifying exhumation histories (tectonic or erosional), magmatism, or landscape evolution. As thermochronology has matured, so have model and interpretational approaches used to convert thermal histories into these more useful geologic histories. Low-temperature thermochronology has been especially important in this regard, as knowledge of thermal processes in the uppermost few kilometers of the crust require consideration of coupled interactions of tectonic, geodynamic, and surface processes. Exciting new developments in these fields in turn drive improved thermochronologic methods and innovative sampling approaches.
    Pages: Online-Ressource (XXII, 620 Seiten)
    ISBN: 0939950707
    Language: English
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Publication Date: 2023-11-18
    Description: The eastern European Alps are shaped by the indentation of Adria into Europe. Recent tomography, depicting detached slab fragments, has been interpreted as evidence of continuous southward subduction of European lithosphere, contrary to an often‐invoked subduction polarity reversal. Orogen‐scale exhumation, driven by rock displacement along active faults, may reflect subduction polarity within the framework of doubly‐vergent Coulomb wedge theory, provided the absence of rheological contrasts across the colliding plates. Low‐temperature thermochronology can evaluate crustal cooling in response to changes in tectonic and erosional boundary conditions. This study investigates the consistency of observed crustal re‐organization, exhumation, and mantle processes in the Eastern Alps. Thermo‐kinematic forward models driven by reconstructions of crustal shortening along the TRANSALP geophysical transect were subjected to variations in shortening rates, thermophysical parameters, and topographic evolution, supplemented by new fission‐track data. The thermo‐kinematic models reproduce: (a) the orogen‐scale structural geometry, (b) the distribution of thermochronometer ages, (c) observed time‐temperature paths, and (f) the present‐day surface heat flux. Results suggest that exhumation is driven by rock displacement along active faults without the need to involve mantle‐driven buoyancy forces. Taken together, the results identify two possible scenarios: if the Tauern Ramp is a retro‐thrust and the southward shift of deformation in the Southern Alps is a response to new Coulomb‐wedge conditions, then our results support a Mid‐Miocene reversal of the subduction polarity. Alternatively, crustal deformation does not reflect mantle processes entailing a high degree of inter‐plate decoupling.
    Description: Plain Language Summary: The convergence between the African and Eurasian plates created the European Alps. This process led to the Eurasian plate underlaying the African plate. It has been argued that this tectonic geometry changed, that is, Adria underlies Europe at present. Here we investigate whether changes in erosion and cooling of the crust over geologic time along a north‐to‐south profile in the Eastern Alps during the collision reflects deep seated mantle processes given the absence of rheological contrasts across the involved tectonic plates. New models for the structural and thermal evolution of the crust along the profile reproduce present‐day structural and thermal observations. Model predictions are sensitive to heat production in the crust. Furthermore, these models indicate that cooling of the crust through erosion was primarily driven by the displacement of rocks toward the surface along active faults. Two possible tectonic scenarios are suggested: The pattern of fault activity during the collision is characteristic for an overlying European plate promoting that now the Adriatic plate lies under the European plate. If this is the case, this change in tectonic geometry likely occurred about 10–20 million years ago. Alternatively, crustal deformation does not reflect mantle processes because the interface between the two colliding plates is highly decoupled along the profile.
    Description: Key Points Exhumation in the eastern European Alps along TRANSALP is primarily driven by cooling through rock displacement along active faults The thermo‐kinematic reconstruction emphasizes contrasts in the deformation north and south along TRANSALP since the Mid‐Miocene In the absence of inter‐plate rheological contrasts deformation patterns favor a reversal in subduction polarity since the Mid‐Miocene
    Description: Deutsche Forschungsgemeinschaft http://dx.doi.org/10.13039/501100001659
    Description: https://doi.org/10.5880/fidgeo.2022.017
    Description: https://doi.org/10.5281/zenodo.7785668
    Description: https://doi.org/10.1186/s40562-017-0098-z
    Description: https://doi.org/10.1016/j.epsl.2004.05.040
    Description: https://doi.org/10.1007/s00531-014-1060-3
    Keywords: ddc:551.8 ; European Alps ; TRANSALP ; thermochronology ; subduction polarity reversal ; tectonic reconstruction ; continental collision
    Language: English
    Type: doc-type:article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Publication Date: 2023-11-24
    Description: The Middle Miocene (15.99–11.65 Ma) of Europe witnessed major climatic, environmental, and vegetational change, yet we are lacking detailed reconstructions of Middle Miocene temperature and precipitation patterns over Europe. Here, we use a high‐resolution (∼0.75°) isotope‐enabled general circulation model (ECHAM5‐wiso) with time‐specific boundary conditions to investigate changes in temperature, precipitation, and δ〈sup〉18〈/sup〉O in precipitation (δ〈sup〉18〈/sup〉O〈sub〉p〈/sub〉). Experiments were designed with variable elevation configurations of the European Alps and different atmospheric CO〈sub〉2〈/sub〉 levels to examine the influence of Alpine elevation and global climate forcing on regional climate and δ〈sup〉18〈/sup〉Op patterns. Modeling results are in agreement with available paleobotanical temperature data and with low‐resolution Middle Miocene experiments of the Miocene Model Intercomparison Project (MioMIP1). However, simulated precipitation rates are 300–500 mm/yr lower in the Middle Miocene than for pre‐industrial times for central Europe. This result is consistent with precipitation estimates from herpetological fossil assemblages, but contradicts precipitation estimates from paleobotanical data. We attribute the Middle Miocene precipitation change in Europe to shifts in large‐scale pressure patterns in the North Atlantic and over Europe and associated changes in wind direction and humidity. We suggest that global climate forcing contributed to a maximum δ〈sup〉18〈/sup〉O〈sub〉p〈/sub〉 change of ∼2‰ over high elevation (Alps) and ∼1‰ over low elevation regions. In contrast, we observe a maximum modeled δ〈sup〉18〈/sup〉O〈sub〉p〈/sub〉 decrease of 8‰ across the Alpine orogen due to Alpine topography. However, the elevation‐δ〈sup〉18〈/sup〉O〈sub〉p〈/sub〉 lapse rate shallows in the Middle Miocene, leading to a possible underestimation of paleotopography when using present‐day δ〈sup〉18〈/sup〉O〈sub〉p〈/sub〉—elevation relationships data for stable isotope paleoaltimetry studies.
    Description: Key Points: A high‐resolution isotope‐enabled general circulation model is used to explore Middle Miocene climate and precipitation δ〈sup〉18〈/sup〉O across Europe. Middle Miocene bi‐directional precipitation change consistent with herpetological fossils and account for precipitation δ〈sup〉18〈/sup〉O variations. Global Miocene climate forcing contributed a max δ〈sup〉18〈/sup〉O change of ∼2‰ over the high Alpine elevation and to ∼1‰ over low elevation.
    Description: German research fondation
    Description: Alexander‐von‐Humboldt foundation, Feodor‐Lynen‐Fellowship
    Description: Alexander‐von‐Humboldt foundation, Humboldt Research Fellowship
    Description: Scientific Steering Committee
    Description: https://mpimet.mpg.de/fileadmin/projekte/ICON-ESM/mpi-m_sla_201202.pdf
    Description: https://gitlab.awi.de/mwerner/mpi-esm-wiso
    Description: https://zenodo.org/record/6308475#.Y0gmDSFS-2w
    Keywords: ddc:550.724 ; Europe ; Middle Miocene ; climate modeling ; stable water isotopes ; temperature ; precipitation ; paleoclimate ; paleoelevation ; Alps
    Language: English
    Type: doc-type:article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Publication Date: 2024-01-30
    Description: This is GNSS data of four stations covering the grounding zone of Priestley Glacier Antarctica. Tidal modulation of ice streams and their adjacent ice shelves is a real-world experiment to understand ice-dynamic processes. We observe the dynamics of Priestley Glacier, Antarctica, using Terrestrial Radar Interferometry (TRI) and GNSS. Ocean tides are predominantly diurnal but horizontal GNSS displacements oscillate also semi-diurnally. The oscillations are strongest in the ice shelf and tidal signatures decay near-linearly in the TRI data over 〉10 km upstream of the grounding line. Tidal flexing is observed 〉6 km upstream of the grounding line including cm-scale uplift. Tidal grounding line migration is small and 〈40 % of the ice thickness. The frequency doubling of horizontal displacements relative to the ocean tides is consistent with variable ice-shelf buttressing demonstrated with a visco-elastic Maxwell model. Taken together, this supports previously hypothesized flexural ice softening in the grounding-zone through tides and offers new observational constraints for the role of ice rheology in ice-shelf buttressing.
    Keywords: Antarctica; ERA-PLANET; GNSS; GPS; Grounding Line; The European network for observing our changing planet
    Type: Dataset
    Format: application/zip, 4 datasets
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    Publication Date: 2024-01-30
    Description: A gridded bathymetry of the sea floor under Ekström Ice Shelf, Antarctica. The seismic data used to map the bathymetry were collected between 2010 and 2018, using two different seismic vibroseis sources. The same snow streamer was used for all data acquisition - a 1500 m long, 60 channel snow streamer, with 25 m group spacing. Each group contains eight gimballed P-wave SM-4, 14 Hz geo-phones. For each seismic profile, the reflection time of the sea floor horizon was identified. The data across all profiles was gridded and depth converted, using an ice velocity of 3601 m/s a sea-water velocity of 1451 m/s.
    Keywords: Bathymetry; Ekström; Ekstrom_Ice_Shelf; Ekström Ice Shelf; Ice shelf; MULT; Multiple investigations; seismic reflection; Sub-EIS-Obs; vibroseis
    Type: Dataset
    Format: image/tiff, 21.5 MBytes
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Publication Date: 2024-01-30
    Description: These data were aquired with a Terrestrial Radar Interferometer overlooking the grounding zone of Priestley Glacier, Antarctica. The time series contains line-of-sight velocities averaged over 3 h over an approximately 8 day period in November 2018. Tidal modulation of ice streams and their adjacent ice shelves is a real-world experiment to understand ice-dynamic processes. We observe the dynamics of Priestley Glacier, Antarctica, using Terrestrial Radar Interferometry (TRI) and GNSS. Ocean tides are predominantly diurnal but horizontal GNSS displacements oscillate also semi-diurnally. The oscillations are strongest in the ice shelf and tidal signatures decay near-linearly in the TRI data over 〉10 km upstream of the grounding line. Tidal flexing is observed 〉6 km upstream of the grounding line including cm-scale uplift. Tidal grounding line migration is small and 〈40 % of the ice thickness. The frequency doubling of horizontal displacements relative to the ocean tides is consistent with variable ice-shelf buttressing demonstrated with a visco-elastic Maxwell model. Taken together, this supports previously hypothesized flexural ice softening in the grounding-zone through tides and offers new observational constraints for the role of ice rheology in ice-shelf buttressing.
    Keywords: Antarctica; flowfields; grounding zone dynamics; Ice dynamics; Priestley_Glacier; Terrestrial Radar Interferometry
    Type: Dataset
    Format: application/zip, 1.5 GBytes
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    Publication Date: 2024-01-30
    Description: These data were aquired with a Terrestrial Radar Interferometer overlooking the grounding zone of Priestley Glacier, Antarctica. The time series contains differential interferograms with a 12h temporal baseline covering an approximately 8 day period in November 2018. Tidal modulation of ice streams and their adjacent ice shelves is a real-world experiment to understand ice-dynamic processes. We observe the dynamics of Priestley Glacier, Antarctica, using Terrestrial Radar Interferometry (TRI) and GNSS. Ocean tides are predominantly diurnal but horizontal GNSS displacements oscillate also semi-diurnally. The oscillations are strongest in the ice shelf and tidal signatures decay near-linearly in the TRI data over 〉10 km upstream of the grounding line. Tidal flexing is observed 〉6 km upstream of the grounding line including cm-scale uplift. Tidal grounding line migration is small and 〈40 % of the ice thickness. The frequency doubling of horizontal displacements relative to the ocean tides is consistent with variable ice-shelf buttressing demonstrated with a visco-elastic Maxwell model. Taken together, this supports previously hypothesized flexural ice softening in the grounding-zone through tides and offers new observational constraints for the role of ice rheology in ice-shelf buttressing.
    Keywords: Antarctica; Differential Interferometry; ERA-PLANET; flowfields; grounding zone dynamics; Ice dynamics; Priestley_Glacier; Terrestrial Radar Interferometry; The European network for observing our changing planet
    Type: Dataset
    Format: application/zip, 218 MBytes
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    Publication Date: 2024-01-30
    Description: Sea floor depth under Ekström Ice Shelf, Antarctica - from seismic reflection profiles collected between 2010 and 2018. For each seismic profile, the reflection time of the sea floor and ice-shelf base was identified and the depth to the sea floor was calculated using an ice velocity of 3601 m/s a sea-water velocity of 1451 m/s. The depths are referenced to mean sea-level (geoid EIGEN-6C4 ). The seismic data used here were collected using two different seismic vibroseis sources. The same snow streamer was used for all data acquisition - a 1500 m long, 60 channel snow streamer, with 25 m group spacing. Each group contains eight gimballed P-wave SM-4, 14 Hz geo-phones. Please note these data are the point data used to create the gridded bathymetry product of the region, found here: doi:10.1594/PANGAEA.907951 Details of data acquisition and processing are given here: doi:10.1029/2019GL086187.
    Keywords: Bathymetry; Bed elevation; Corrected for surface elevation using the REMA model, re-reference to the EIGEN6C4 Geoid; Ekström; Ekstrom_Ice_Shelf; Ekström Ice Shelf; Ice shelf; LATITUDE; LONGITUDE; MULT; Multiple investigations; Number; seismic reflection; Sub-EIS-Obs; vibroseis
    Type: Dataset
    Format: text/tab-separated-values, 117684 data points
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    Publication Date: 2024-01-20
    Keywords: Age, (U‐Th)/He dating; Age, error; Age, mineral; CN16-004; CN16-007; CN16-016; CN16-017; CN16-018; CN16-019; CN16-020; CN16-032; CN16-033; CN16-034; CN16-036; CN16-037; CN16-048; CN16-064; CN16-069; CN16-084; CN16-092; CN16-102; CN16-103; Comment; cooling age; ELEVATION; Event label; exhumation; Himalayas; LATITUDE; LONGITUDE; Nepal; ROCK; Rock sample; ZHe
    Type: Dataset
    Format: text/tab-separated-values, 57 data points
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    Publication Date: 2024-01-20
    Keywords: Age, error; Age, mineral; alpha-ejection correction; CN16-004; CN16-007; CN16-016; CN16-017; CN16-018; CN16-019; CN16-020; CN16-032; CN16-033; CN16-034; CN16-036; CN16-037; CN16-048; CN16-064; CN16-069; CN16-084; CN16-092; CN16-102; CN16-103; cooling age; Event label; exhumation; Helium-4; Himalayas; Mass; Mass, standard error; Nepal; Ratio; ROCK; Rock sample; Sample code/label; Size; Thorium; Thorium/Uranium ratio; Uranium; ZHe
    Type: Dataset
    Format: text/tab-separated-values, 1197 data points
    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...