Published in Geophysical Research Letters, 2019
Understanding deformation in ice shelves is necessary to evaluate the response of ice shelves to thinning. We study microseismicity associated with ice shelf deformation using 9 broadband seismographs deployed near a rift on the Ross Ice Shelf. From December 2014 - November 2016, we detect 5948 icequakes generated by rift deformation. Ocean swell, infragravity waves and a signicant tsunami arrival do not affect seismicity. Instead, seismicity correlates with tidal phase on diurnal timescales and inversely correlates with air temperature on multi-day and seasonal timescales. Spa tial variability in tidal elevation tilts the ice shelf, and seismicity is concentrated while the shelf slopes downward toward the ice front. During especially cold periods, thermal stress and embrittlement enhance fracture along the rift. We propose that thermal stress and tidally-driven gravitational stress produce rift seismicity with peak activity in the winter.
Recommended citation: Olinger, S. D., D. A. Wiens, B. P. Lipovsky, R. C. Aster, A. A. Nyblade, R. A. Stephen, P. D. Bromirski, P. Gerstoft, Z. Chen (2019). " Tidal and Thermal Stresses Drive Seismicity along a Major Ross Ice Shelf Rift" Geophysical Research Letters Accepted May 17, 2019. http://bradlipovsky.github.io/files/Olinger2019.pdf