Development of the Next Generation of Seismological Instrumentation for Polar Environments

Abstract:

Ice covered regions comprise >10% of Earth’s continental area; and include regions with poorly understood ice dynamics, ice shelf stability, hydrology, tectonic histories and basic geologic structure both deep and shallow. Scientific investigations of these regions are challenged by extreme weather, limited and expensive logistics, and the physical conditions of the ice environment. We report on the next development of a new NSF MRI-supported community seismic capability for studying ice-covered regions– the Geophysical Earth Observatory for Ice Covered Environments (GEOICE). This project is fundamentally motivated by the need to densify and optimize the collection of high-quality data relevant to key solid Earth and cryosphere science questions. The instrument capability will include a hybrid seismograph pool of broadband and intermediate elements, for observation of both long-period (e.g., long-period surface waves and slow sources) and intermediate-to-short-period (e.g., teleseismic body waves local seismicity, impulsive or extended glaciogenic signals). The GEOICE instrument, and its power and other ancillary systems, will be specifically designed to both withstand conditions associated with icy environments, including cold/wet conditions and high-latitude solar limitations, and to require minimal installation time and logistical load (i.e., size and weight), while maximizing ease-of-use in the field, in data handling, and in telemetry compatibility. Key features will include a design that integrates the seismometer and data logger into a single environmentally and mechanically robust housing, very low power requirements (<~1 watt) for the intermediate-band systems, and advanced power/battery systems that optimize battery capacity and operational limits. The envisioned ~125 element GEOICE instruments will nearly double the current polar inventory of stations and will be maintained and supported at the IRIS PASSCAL Instrument Center to ensure full and flexible peer-reviewed community use.