Seismological constraints on ice properties at Dome C, Antarctica, from H/V measurements.

• Published in: Antarctic Science
• Main Authors: Lévêque, Jean-Jacques, Maggi, Alessia, Souriau, Annie
• Other Authors: Sismologie (IPGS) (IPGS-Sismologie), Institut de physique du globe de Strasbourg (IPGS), Université de Strasbourg (UNISTRA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut de recherche en astrophysique et planétologie (IRAP), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales Toulouse (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales Toulouse (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), CASE-IPY, ANR-07-BLAN-0147,CASE-IPY,Concordia Antarctic Seismic Experiment (International Polar Year)(2007)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2010
• Subjects: Antarctic seismological stations; Concordia; firn; seismic ambient noise; [SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph]; [PHYS.PHYS.PHYS-GEO-PH]Physics [physics]/Physics [physics]/Geophysics [physics.geo-ph]; [SDE.MCG]Environmental Sciences/Global Changes; Antarctic; The Antarctic; Antarc*; Antarctic Science; Antarctica; Ice cap
• Online Access: https://hal.science/hal-00679373; https://hal.science/hal-00679373/document; https://hal.science/hal-00679373/file/LevequeEtal2010.pdf; https://doi.org/10.1017/S0954102010000325

International audience The French-Italian Concordia (CCD) seismological station at Dome C is one of two observatories setup on the ice cap in the interior of the Antarctic continent. We analysed the seismic signal due to ambient noise at this station and at three temporary stations 5 km away from Concordia, in order to specify the ice properties beneath them. A method based on the horizontal to vertical (H/V) spectral ratio, commonly used to analyse soil response in seismic regions, was applied to the Antarctic stations. The main peak in the spectral ratios is observed at frequencies 6.7-8 Hz at the Dome C stations, but it is not observed at another station on the ice cap, QSPA, where the sensor is buried at 275m depth. This peak can be explained by a 23m thick unconsolidated snow or firn layer with a low S-wave velocity of 0.7kms-1, overlying a consolidated layer with S-wave velocity 1.8 km s-1. Despite the non-uniqueness of the solutions obtained by fitting the H/V spectra, this model is preferred because the depth of the velocity contrast coincides with the density at which ice particles arrange themselves in a continuous, dense lattice. A small variability of this structure is observed around Dome C.