WITHDRAWN Glacier Seismology Application
Description:
WITHDRAWN Seismology at glaciers and ice sheets has the potential to remotely track water flow and changes in the frictional properties of glacier and ice sheet beds. To better understand the frictional properties of the bed of the Greenland Ice Sheet and its response to meltwater input from the ice sheet surface, we installed an array of GEObit and other compact, posthole-type seismometers. Following 5 months of continuous operation, visited only once to redrill the sensors following melt out to the surface, the sensors were recovered. Both the GEObit and other sensors behaved comparably, recording tens of thousands of small (<M1) icequakes. While the majority of icequakes originated from shallow depths near the ice sheet surface, hundreds of these icequakes have characteristics consistent with an origin at the ice sheet base. We examined the spatial and temporal patterns of these icequakes to reveal the heterogenous frictional properties of the ice sheet bed.
In this work GEObit equipment was used for the seismic monitoring of the glaciers and they performed great. The sensors (C100 borehole seismometers) were placed into post holes of 1.5 5m depth drilled into the ice. The dataloggers (model Sri32 - older version of the GEOthree datalogger) were placed at the surface, into Peli type cases. The seismographs were able to get power from a small 35Ah battery and a small solar panel because of their low power requirements. The sensor bandwidth is 10sec to 98Hz and the sensitivity is 1500V/m/s. The digitizer uses high resolution 32bit ADC and up to 1000sps. The data are stored into a microSD card with capacity 32Gbytes, enough to store more than a year’s data. The sensors left to operate unattended for several months, recording at 100sps. At the end of the recording period, the data were downloaded from the microSD cards to the computer for processing.
Session: ESC-SSA Joint Session: Climate Change and Environmental Seismology [Poster Session]
Type: Poster
Date: 5/3/2024
Presentation Time: 08:00 AM (local time)
Presenting Author: Nikos
Student Presenter: No
Invited Presentation:
Authors
Nikos Germenis Presenting Author Corresponding Author ngermenis@geobit-instruments.com Geobit Instruments |
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WITHDRAWN Glacier Seismology Application
Category
ESC-SSA Joint Session: Climate Change and Environmental Seismology