Seismic Monitoring Infrastructure at the Utah FORGE Site
Induced microseismicity, comprising ultra-low-magnitude earthquake events which are imperceptible at the surface, is an important focus of research at Utah FORGE, and accurate locations of these events are being used to identify fractures that open up during cold water injection. Eventually, these same fractures will provide the means by which injected water becomes hot to produce geothermal energy. As western Utah is prone to seismicity resulting from tectonic forces, the state-of-the-art Utah FORGE seismic network also plays a role in monitoring natural earthquake activity in the region.
To achieve the -2 magnitude detection limits required for EGS research, the high-resolution seismic network is near completion. Some of seismometers are deployed to depths >3000 feet below the surface in vertical wells that surround the bottom part of the deviated injection well 16A(78)-32. A geophone and an accelerometer are permanently installed into the bottom of 68-32, and well 78-32 is instrumented with a distributed acoustic sensor (DAS). A second, deep vertical well 78B-32, drilled in July, 2021, is also instrumented with a second DAS fiber. Downhole arrays of seismometers will be lowered on a cable into wells 56-32, 58-32 and 78-32 for the upcoming stimulation planned for September 2021.
The rest of the seismic network is made of permanent seismometers that have been or will soon be installed to form two concentric rings shown in the map. The stations designated BOR are located in shallow wells about 100 feet deep and the ones designated ROC are installed on bedrock. Additional temporary arrays comprising a large number of surface nodal instruments are deployed for each scheduled period of stimulation lasting several weeks.
The University of Utah Seismograph Stations (UUSS) is responsible for monitoring, recording and archiving all seismic data acquired by the Utah FORGE network, and raw waveform data can be viewed through webicorders available on their monitoring site. Archived data is available from IRIS and the Center for High Performance Computing, University of Utah. Here's How to Access the Data.
For more information about earthquake hazards check out the links below