Results 181 to 190 of about 314,168 (203)
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Convective mixing of air in firn at four polar sites
Earth and Planetary Science Letters, 2006Air withdrawn from the firn at four polar sites (Dome Fuji, H72 and YM85, Antarctica and North GRIP, Greenland) was measured for δ 15 No f N2 and δ 18 Oo f O2 to test for the presence of convective air mixing in the top part of the firn, known as the “convective zone”.
Nakazawa Takakiyo +2 more
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Settlement of a Large Structure on Polar Firn
Current Practices in Cold Regions Engineering, 2006Sustainable engineering in remote cold regions requires use of readily-available natural materials for engineering applications such as building foundations. Construction of a large structure at the South Pole provides a unique opportunity to observe settlement of a compacted snow and firn foundation.
Jason C. Weale, George L. Blaisdell
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A method for the measurement of seismic attenuation in polar firn
2023We present seismic measurements of the firn column at Korff Ice Rise, West Antarctica, including measurements of compressional- and shear-wave velocity and attenuation. We describe a modified spectral-ratio method of measuring the seismic quality factor (Q) based on analysis of diving waves, which enables us to characterise the attenuative structure of
Ronan Agnew +4 more
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The in-situ dielectric constant of polar firn revisited
Cold Regions Science and Technology, 1995Abstract The success in using VHF and UHF frequency systems for sounding polar ice sheets has been tempered by an uncertainty in the in-situ dielectric constant which controls the effective velocity of an electromagnetic wave propagating in an air-ice mixture. An empirical equation for determining the relative real dielectric constant ϵ′r vs. density
Austin Kovacs +2 more
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Polar firn layering in radiative transfer models
, 2016 For many applications in the geosciences, remote sensing is the only feasible method of obtaining data from large areas with limited accessibility.
Hoerhold, Maria, Linow, Stefanie
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Use of Shear Waves to Measure Poisson's Ratio in Polar Firn
Journal of Environmental and Engineering Geophysics, 2007Abstract We conducted a seismic experiment on polar firn on Adelaide Island, Antarctica. We measured the speed of compressional and shear waves at different depths in the firn by sampling waves that return to the surface following continuous refraction.
King, Edward C., Jarvis, Eric P.
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Is the densification of polar firn abnormal ?
, 2009 The high resolution density of 16 firn and shallow ice cores from Greenland and Antarctica was determined by applying the gamma-ray absorption method. Profiles of mean density and density fluctuations (i. e.
Kipfstuhl, Sepp +3 more
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Dynamic recrystallization in polar firn and ice
, 2009 The classical view of the microstructure evolution in polar is: normal grain growth, i.e. grain growth driven by grain boundary surface energy, predominates in the upper part of an ice sheet; in the middle part grain division by polygonization, which ...
Azuma, N. +4 more
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Grain Size Changes During the Deformation of Polar Firn
SSRN Electronic Journal, 2022Yuan Li +3 more
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