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Distributed Acoustic Sensing (DAS) of Seismic Properties in a Borehole drilled on a Fast‐Flowing Greenlandic Outlet Glacier

Published version
Peer-reviewed

Type

Article

Change log

Authors

Booth, Adam D 
Christoffersen, Poul  ORCID logo  https://orcid.org/0000-0003-2643-8724
Schoonman, Charlotte 
Clarke, Andy 
Hubbard, Bryn 

Abstract

Distributed Acoustic Sensing (DAS) is a new technology in which seismic energy is detected, at high spatial and temporal resolution, using the propagation of laser pulses in a fibre-optic cable. We show analyses from the first glaciological borehole DAS deployment to measure the englacial and subglacial seismic properties of Store Glacier, a fast-flowing outlet of the Greenland Ice Sheet. We record compressional and shear waves in 1043 m-deep vertical seismic profiles, sampled at 10 m vertical resolution, and detect a transition from isotropic to anisotropic ice at 84% of ice thickness, consistent with the Holocene-Wisconsin transition. We identify subglacial reflections originating from the base of a 20 m-thick layer of consolidated sediment and, from attenuation measurements, interpret temperate ice in the lowermost 100 m of the glacier. Our findings highlight the promising potential of DAS technology to constrain the seismic properties of glaciers and ice sheets.

Description

Keywords

Distributed Acoustic Sensing (DAS), Vertical Seismic Profile (VSP), Greenland Ice Sheet, anisotropy, subglacial sediment, borehole surveying

Journal Title

Geophysical Research Letters

Conference Name

Journal ISSN

0094-8276
1944-8007

Volume Title

Publisher

Wiley-Blackwell
Sponsorship
European Commission Horizon 2020 (H2020) ERC (3276207)