Monitoring Seasonal Fluctuation and Long-term trends for the Greenland Ice Sheet using Seismic Noise Correlations
Abstract
The Greenland Ice sheet (GrIS), the second largest ice body in the world (follows the Antarctic ice sheet), stores ~3 million km3 worth of ice. During recent decades, the GrIS encounters increasing mass loss due to the overall warming condition, and the GrIS still holds enough water to potentially raise the mean sea-level over 7.4 m. One important feature of the mass change of the GrIS is that it presents strong seasonal fluctuations (one-year cycle). The overall mass loss in summertime and mass gain in wintertime is mainly due to large meltwater runoffs in the summertime, and overall high precipitation in the wintertime. Besides the seasonal fluctuation, we also observe the long-term trend of the GrIS in recent years. The abnormal warm-cold transition during 2012-2013 has been noted by many studies using a variety of techniques (e.g., gravity measurements, surface elevation changes).
In this study, we use the relative seismic velocity change (dv/v) retrieved from the auto-correlations of the cross components of seismic recordings, to monitor both seasonal fluctuation and long-term trend of the GrIS. Our results show that (1) the dv/v presents <2 months lag of the surface mass change in the southwest and northeast Greenland. In addition, the central Greenland regions are probably dominated by the annual snowfall. (2) In the SW Greenland, the mass change shows strongest reaction to the "2012-2013 warm-cold transition", where the dv/v presents a transition of decrease-increase long term trend before and after 2013. This is consistent with the regional mass change rate (dM/dt). (3) In the SE Greenland, the dv/v has a negative correlation with the mass change, which might be due to large spatial mass change variation or large uncertainties of the regional dv/v measurement.- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2022
- Bibcode:
- 2022AGUFM.S12C..02L