Seismic Analysis of a Pingo, Svalbard Islands, Arctic
G. Rossi, F. Accaino, J. Boaga, L. Petronio, R. Romeo and W. Wheeler
Event name: Near Surface Geoscience 2015 - 21st European Meeting of Environmental and Engineering Geophysics
Session: Characterization and Monitoring in Alpine and Polar Regions
Publication date: 06 September 2015
Info: Extended abstract, PDF ( 1.66Mb )
Price: € 20
Pingos are oval dome-shaped hills that form in permafrost areas when the hydrostatic pressure of freezing groundwater causes the raising of frozen ground. One of the most famous and studied pingos is the Innerhytta pingo in Adventdalen, Svalbard Islands, with a giant icefall, testifying the significant fluid circulation in their correspondence. Its characteristics make it an ideal site for the seismic experiment of the Italy-Norway project IMPERVIA, aimed to define the inner structure of the pingo, and the ice-bound permafrost full thickness. Another task was to test the capabilities of near-surface seismic techniques in the severe Arctic environment, both in terms of sources and sensors, and of methodologies. The survey took place in spring 2014. We tested three sources (sledge-hammer, Seisgun, and firecrackers) evaluating their efficiency in terms of penetration and resolution, and 4.5 Hz and 14. Hz geophones and a 14 Hz mini-snow streamer. We acquired three intersecting lines, to enable an adequate tomographic analysis of the pingo structure, and we did two surface wave experiments along two of the lines. The data quality is good, allowing the recognition of several refracted and reflected events and a first topographic model of the velocity structure of the pingo.