Growing Capabilities of the SAGE/IRIS Facility for Conducting Near Surface and Upper Crustal Geophysical Studies

Session: Advances in Upper Crustal Geophysical Characterization
Type: Oral
Date: 4/29/2020
Time: 05:30 PM
Room: 215 + 220
Description: 

Under NSF’s Seismological Facilities for the Advancement of Geoscience, IRIS is broadening the portable geophysical instrumentation available at the PASSCAL Instrument Center to add and enhance observational capabilities for Principal Investigators (PIs). This includes more optimized geophysical tools for characterizing the near surface and upper crust. Over the past three years, IRIS has established a pool of nearly one thousand 5 Hz 3-component Fairfield nodes (all-in-one geophone, digitizer, battery - 1 month duration). These allow for denser sampling of high frequency wavefields compared to previous generations of geophone based surveys. During the next few years, IRIS will continue to add nodes to improve the capacity for “Large N” style experiments at a variety of scales. We have also procured a new P and S wave seismic source, operated by the Seismic Source Facility at UTEP. This provides a new controlled source shallow imaging option to complement the high resolution seismometry. Propelled Energy Generators are also available for shallow seismic surveying.

Meanwhile, magnetotelluric (MT) instruments are being added to the suite of IRIS PASSCAL instrumentation. The initial batch of legacy MT instruments has supported lithosphere-scale studies, but we will add wideband systems with the capability of characterizing the resistivity of the shallow crust at a resolution of hundreds of meters or less. In addition, we will explore options for audio MT instruments, further improving the ability to resolve shallower structure.

Finally, IRIS has procured a ground penetrating radar for use by the PI community. This is part of a growing effort to support investigations focused on very near-surface geophysical targets, including the critical zone. IRIS is working with the near surface geophysics community to leverage funding opportunities that would establish a significant pool of community instruments. In all cases, IRIS will continue to provide comprehensive training and support for instrument usage, data offload, metadata handling and archival with the IRIS DMC at no cost.

Presenting Author: Andrew M. Frassetto

Authors