Results 1 to 10 of about 564 (170)

Thermal conductivity of polar firn

Journal of Glaciology, 2022
The vast Greenland and Antarctic Ice Sheets are covered by many tens of meters of polar firn, which is snow that is years to centuries old and has experienced significant metamorphism. Both ice-sheet modeling and decoding satellite data require knowledge
Simon E. Oster, Mary R. Albert
doaj   +2 more sources

Observations of the creep of polar firn [PDF]

Journal of Glaciology, 2022
Constant-load creep tests were performed at −10°C at various compressive stresses from 0.05 to 0.75 MPa on specimens taken every 10 m along a firn core extracted at Summit, Greenland in June 2017.
Yuan Li, Ian Baker
doaj   +2 more sources

Historical porosity data in polar firn [PDF]

Earth System Science Data, 2020
In the 1990s, closed and open porosity volumes of firn samples were measured by J.-M. Barnola using the technique of gas pycnometry, on firn from three different polar sites.
K. Fourteau, L. Arnaud, X. Faïn, P. Martinerie, D. M. Etheridge, V. Lipenkov, J.-M. Barnola   +6 more
doaj   +6 more sources

The Onset of Recrystallization in Polar Firn

Geophysical Research Letters, 2023
Constraining the onset of dynamic recrystallization (DRX) and its effects on the mechanical properties of firn is crucial for firn densification modeling.
Ayobami Ogunmolasuyi, Andrii Murdza, Ian Baker   +2 more
doaj   +2 more sources

On the impact of impurities on the densification of polar firn [PDF]

Earth and Planetary Science Letters, 2012
Understanding polar firn densification is crucial for reconstructing the age of greenhouse gas concentrations extracted from ice cores, and for the interpretation of air in ice as a dating tool or as a climate proxy. Firn densification is generally modeled as a steady burial and sintering process of defined layers, where the structure of the layering ...
Thomas Laepple, Matthias Bigler, Hubertus Fischer   +2 more
exaly   +4 more sources

Evidence of dynamic recrystallization in polar firn [PDF]

Journal of Geophysical Research, 2009
Microstructural analyses have been performed on polar firn from the European Project for Ice Coring in Antarctica drilling site in Dronning Maud Land, Antarctica. The results derived from images of the firn structure in microscopic resolution indicate that dynamic recrystallization is active in firn at all depths, and it dominates the evolution of the ...
Sérgio H Faria, Nobuhiko Azuma, Johannes Freitag   +2 more
exaly   +5 more sources

Local Weather Conditions Create Structural Differences between Shallow Firn Columns at Summit, Greenland and WAIS Divide, Antarctica

Atmosphere, 2020
Understanding how physical characteristics of polar firn vary with depth assists in interpreting paleoclimate records and predicting meltwater infiltration and storage in the firn column.
Ian E. McDowell, Mary R. Albert, Stephanie A. Lieblappen, Kaitlin M. Keegan   +3 more
doaj   +3 more sources

A Micro-Mechanical Model for the Transformation of Dry Polar Firn Into Ice Using the Level-Set Method

Frontiers in Earth Science, 2020
Interpretation of greenhouse gas records in polar ice cores requires a good understanding of the mechanisms controlling gas trapping in polar ice, and therefore of the processes of densification and pore closure in firn (compacted snow).
Kévin Fourteau, Fabien Gillet-Chaulet, Patricia Martinerie, Xavier Faïn   +3 more
doaj   +3 more sources

The densification of layered polar firn [PDF]

Journal of Geophysical Research, 2011
S Kipfstuhl, F Wilhelms
exaly   +4 more sources

Observations of creep of polar firn at different temperatures [PDF]

The Cryosphere
To improve our understanding of firn compaction and deformation processes, constant-load compressive creep tests were performed on specimens from a Summit, Greenland (72°35′ N, 38°25′ W) firn core that was extracted in June 2017.
Y. Li, Y. Li, K. Keegan, I. Baker
doaj   +3 more sources