Results 31 to 40 of about 795 (198)

Porosity dependence of elastic moduli of snow and firn

open access: yesJournal of Glaciology, 2021
Measurements of elastic wave velocities enable non-destructive estimation of the mechanical properties, elastic moduli and density of snow and firn.
Colin M. Sayers
doaj   +1 more source

A new multi-gas constrained model of trace gas non-homogeneous transport in firn: evaluation and behaviour at eleven polar sites [PDF]

open access: yesAtmospheric Chemistry and Physics, 2012
Insoluble trace gases are trapped in polar ice at the firn-ice transition, at approximately 50 to 100 m below the surface, depending primarily on the site temperature and snow accumulation.
E. Witrant   +10 more
doaj   +1 more source

Seismic observations of a complex firn structure across the Amery Ice Shelf, East Antarctica

open access: yesJournal of Glaciology, 2021
We use seismic refraction data to investigate the firn structure across a suture zone on the Amery Ice Shelf, East Antarctica, and the possible role of glacier dynamics in firn evolution.
Hannes Hollmann   +4 more
doaj   +1 more source

The impact of ice layers on gas transport through firn at the North Greenland Eemian Ice Drilling (NEEM) site, Greenland [PDF]

open access: yesThe Cryosphere, 2014
Typically, gas transport through firn is modeled in the context of an idealized firn column. However, in natural firn, imperfections are present, which can alter transport dynamics and therefore reduce the accuracy of reconstructed climate records.
K. Keegan, M. R. Albert, I. Baker
doaj   +1 more source

Ambient high-frequency seismic surface waves in the firn column of central west Antarctica

open access: yesJournal of Glaciology, 2022
Firn is the pervasive surface material across Antarctica, and its structures reflect its formation and history in response to environmental perturbations.
Julien Chaput   +3 more
doaj   +1 more source

Bidirectional permeability measurements of polar firn [PDF]

open access: yesAnnals of Glaciology, 2002
AbstractIce cores provide a valuable archive of climate history. for a complete understanding of this archive, it is important to understand air–snow exchange processes through the snow and firn in order to fully decode the ice-core record. Transport processes through the snow and firn are dependent upon their physical properties.
Gina L. Luciano, Mary R. Albert
openaire   +1 more source

Dispersion in deep polar firn driven by synoptic-scale surface pressure variability [PDF]

open access: yesThe Cryosphere, 2016
Commonly, three mechanisms of firn air transport are distinguished: molecular diffusion, advection, and near-surface convective mixing. Here we identify and describe a fourth mechanism, namely dispersion driven by synoptic-scale surface pressure ...
C. Buizert, J. P. Severinghaus
doaj   +1 more source

Gas isotope thermometry in the South Pole and Dome Fuji ice cores provides evidence for seasonal rectification of ice core gas records [PDF]

open access: yesThe Cryosphere, 2022
Gas isotope thermometry using the isotopes of molecular nitrogen and argon has been used extensively to reconstruct past surface temperature change from Greenland ice cores. The gas isotope ratios δ15N and δ40Ar in the ice core are each set by the amount
J. D. Morgan   +7 more
doaj   +1 more source

Spatial Distribution of Crusts in Antarctic and Greenland Snowpacks and Implications for Snow and Firn Studies

open access: yesFrontiers in Earth Science, 2021
The occurrence of snowpack features has been used in the past to classify environmental regimes on the polar ice sheets. Among these features are thin crusts with high density, which contribute to firn stratigraphy and can have significant impact on firn
Alexander H. Weinhart   +5 more
doaj   +1 more source

Wherefore the Magic? The Evolutionary Role of Psilocybin in Nature. [PDF]

open access: yesEcol Evol
This study explores the evolutionary role of psilocybin, the psychedelic compound found in Psilocybe mushrooms. We provide the first experimental tests of defence and community‐level evidence for invertebrate responses to psilocybin‐producing fungi, revealing significant negative effects on invertebrate locomotion, development, and survival.
Matthews Nicholass KJ   +16 more
europepmc   +2 more sources

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