Origin of englacial stratigraphy at three deep ice core sites of the Greenland Ice Sheet by synthetic radar modelling
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Origin of englacial stratigraphy at three deep ice core sites of the Greenland Ice Sheet by synthetic radar modelling. / Mojtabavi, Seyedhamidreza; Eisen, Olaf; Franke, Steven; Jansen, Daniela; Steinhage, Daniel; Paden, John; Dahl-Jensen, Dorthe; Weikusat, Ilka; Eichler, Jan; Wilhelms, Frank.
In: Journal of Glaciology, Vol. 68, No. 270, 0022143021001374, 23.02.2022.Research output: Contribution to journal › Journal article › Research › peer-review
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TY - JOUR
T1 - Origin of englacial stratigraphy at three deep ice core sites of the Greenland Ice Sheet by synthetic radar modelling
AU - Mojtabavi, Seyedhamidreza
AU - Eisen, Olaf
AU - Franke, Steven
AU - Jansen, Daniela
AU - Steinhage, Daniel
AU - Paden, John
AU - Dahl-Jensen, Dorthe
AU - Weikusat, Ilka
AU - Eichler, Jan
AU - Wilhelms, Frank
PY - 2022/2/23
Y1 - 2022/2/23
N2 - During the past 20 years, multi-channel radar emerged as a key tool for deciphering an ice sheet's internal architecture. To assign ages to radar reflections and connect them over large areas in the ice sheet, the layer genesis has to be understood on a microphysical scale. Synthetic radar trace modelling based on the dielectric profile of ice cores allows for the assignation of observed physical properties' variations on the decimetre scale to radar reflectors extending from the coring site to a regional or even whole-ice-sheet scale. In this paper we rely on the available dielectric profiling data of the northern Greenland deep ice cores: NGRIP, NEEM and EGRIP. The three records are well suited for assigning an age model to the stratigraphic radar-mapped layers, and linking up the reflector properties to observations in the cores. Our modelling results show that the internal reflections are mainly due to conductivity changes. Furthermore, we deduce fabric characteristics at the EGRIP drill site from two-way-travel-time differences of along and across-flow polarized radarwave reflections of selected horizons (below 980 m). These indicate in deeper parts of the ice column an across-flow concentrated c-axis fabric.
AB - During the past 20 years, multi-channel radar emerged as a key tool for deciphering an ice sheet's internal architecture. To assign ages to radar reflections and connect them over large areas in the ice sheet, the layer genesis has to be understood on a microphysical scale. Synthetic radar trace modelling based on the dielectric profile of ice cores allows for the assignation of observed physical properties' variations on the decimetre scale to radar reflectors extending from the coring site to a regional or even whole-ice-sheet scale. In this paper we rely on the available dielectric profiling data of the northern Greenland deep ice cores: NGRIP, NEEM and EGRIP. The three records are well suited for assigning an age model to the stratigraphic radar-mapped layers, and linking up the reflector properties to observations in the cores. Our modelling results show that the internal reflections are mainly due to conductivity changes. Furthermore, we deduce fabric characteristics at the EGRIP drill site from two-way-travel-time differences of along and across-flow polarized radarwave reflections of selected horizons (below 980 m). These indicate in deeper parts of the ice column an across-flow concentrated c-axis fabric.
KW - Anisotropic ice
KW - ice core
KW - radio-echo sounding
KW - DOME-C
KW - EAST ANTARCTICA
KW - 1ST CHRONOLOGY
KW - ACCUMULATION
KW - PROFILES
KW - PATTERNS
KW - INTERIOR
KW - VELOCITY
KW - GRIP
KW - FLOW
U2 - 10.1017/jog.2021.137
DO - 10.1017/jog.2021.137
M3 - Journal article
VL - 68
JO - Journal of Glaciology
JF - Journal of Glaciology
SN - 0022-1430
IS - 270
M1 - 0022143021001374
ER -
ID: 302387026