Thermally induced icequakes detected on blue ice areas of the East Antarctic ice sheet

• DOI: 10.1017/aog.2019.26
• Publication Date: 2019-06-24T07:58:04Z
• Authors: Denis Lombardi; Irina Gorodetskaya; Guilhem Barruol; Thierry Camelbeeck
• Keywords: Katabatic wind; Outcrop

ABSTRACT Over a year of seismic observations, ~5000 short duration icequakes were detected by permanent broadband station installed at the Princess Elisabeth base, located ~180 km inland in eastern Dronning Maud Land, East-Antarctica. Icequake detection via waveform pattern recognition indicates presence two dominating clusters events, totalizing ~1500 icequakes. The corresponding icequake locations point towards distinct zones outcropping blue ice areas (BIAs) respectively 4 and 1 from station, both on leeward side nunatak protruding through sheet. temporal occurrence these suggests close genetic link with thermal contraction caused significant surface cooling controlled, summer variations diurnal solar radiation winter strong during cold katabatic regimes. Further analysis demonstrates dependence absolute temperature its change. Besides providing information fracture mechanics rheology, investigations may be regarded as ground-based proxy for monitoring state BIAs, characterization ice-sheet ablation zones.