Monitoring Seasonal Fluctuation and Long‐Term Trends for the Greenland Ice Sheet Using Seismic Noise Auto‐Correlations
Bingxu Luo, Shuo Zhang, Hejun Zhu
Abstract
Abstract One important feature of the Greenland Ice Sheet (GrIS) change is its strong seasonal fluctuation. Taking advantage of deployed seismographic stations in Greenland, we apply cross‐component auto‐correlation of seismic ambient noise to measure in‐situ near surface relative velocity change ( dv / v ) in different regions of Greenland. Our results demonstrate that dv / v measurements for most stations have less than 3 months lag times in comparison to the surface mass change. These various lag times may provide us constraints for the thickness of the subglacial till layer over different regions in Greenland. Moreover, in southwest Greenland, we observe a change in the long‐term trend of dv / v for three stations, which might be consistent with the mass change rate ( dM / dt ) due to the “2012–2013 warm‐cold transition.” These observations suggest that seismic noise auto‐correlation technique may be used to monitor both seasonal and long‐term changes of the GrIS.