In an effort to provide new and improved geophysical sensing capabilities for the study of ice sheets in Antarctica and Greenland, or to study mountain glaciers, we are developing a network of wirelessly interconnected seismic and GPS sensor nodes (called “geoPebbles”), with the primary objective of making such instruments more capable and cost effective.

Each geoPebble is a self- contained, wirelessly connected sensor for collecting seismic measurements and position information. Each node is built around a three-component seismic recorder, which includes an amplifier, filter, and 24-bit analog-to-digital module that can sample data at up to 10 kHz. Each unit also includes a microphone channel to record the ground-coupled airwave from the seismic source. The timing for each node is available through a carrier-phase measurement of the L1 GPS signal at an absolute accuracy of better than a tenth of a microsecond and relative positioning accuracy of 1-2 decimeters. Each geoPebble includes an internal battery, ample internal storage, wireless communications, wireless charging capability and auxiliary measurements capability (up to eight 10-bit channels at low sample rates). Data will be transmitted in real time to a central site, and also stored locally for later download (in case of radio link problems).

Geophysical experiments in the polar region are logistically difficult. With the geoPebble system, the cost of doing today’s experiments (low-resolution, 2D) will be significantly reduced, and the cost and feasibility of doing tomorrow’s experiments (integrated seismic, positioning, 3D, etc.) will be reasonable.

PIs:  Dr. Sridhar Anandakrishnan & Dr. Sven Bilen

Sponsors: NSF

Collaborators: Penn State Department of Geosciences

Students: Mike Conway, Aaron Fleishman, Tyler Boehmer, Tim Brubaker