Time-lapse surface wave monitoring of permafrost thaw using distributed acoustic sensing and a permanent automated seismic source

• DOI: 10.1190/segam2017-17774027.1
• Publication Date: 2017-08-17T17:37:28Z
• Authors: Jonathan Ajo-Fran...; Shan Dou; Thomas Daley; Barry Freifeld; Michelle Robertson; Craig Ulrich; Todd Wood; Ian Eckblaw; Nathan Lindsey; Eileen Martin; Anna Wagner
• Keywords: National laboratory; Distributed Acoustic Sensing

We present preliminary results from an intermediate scale field experiment exploring the seismic response of dynamic permafrost thaw generated by active heating. The focus our project was to evaluate utility surface wave monitoring detect precursors thaw-induced subsidence, a common geotechnical hazard in polar regions. In this study, we timelapse measurements conducted over duration experiment. unique aspect combination semi-permanent orbital vibrator (SOV) source and distributed acoustic sensing measure variations propagation. SOV, energized for 22 sweeps every night, deployed approximately 2 months, collecting 60 daily surveys. Large temporal velocity, as well spectral characteristics were observed. After examination precipitation soil moisture data, such changes convincingly linked rainfall events. A cross-equalization approach developed assist removing effect; after processing, decreasing trend shear velocity appears remain, potentially signature controlled process. Presentation Date: Monday, September 25, 2017 Start Time: 4:20 PM Location: 370C Type: ORAL