This project will install and operate a permanent seismic observatory illuminating the volume of the Homestake Mine DUSEL site from all six possible directions. We have chosen the Homestake site because it offers a unique opportunity - the large volume of mine working of the deepest mine in North America is surrounded and underlain by literally hundreds of open bore holes, which can affordably be instrumented with accelerometers. The project leverages the $32 million the State of South Dakota, and the $20 million the philanthropist Sanford are presently investing in reopening the Homestake Mine for research and education. The proposal brings strong backing from the Lawrence Berkeley National Laboratory (LBNL), which is providing the research efforts of two leading seismologists, seismic instrumentation, and technical support.
The seismic array will allow the community to image rapid dynamic changes in the rock mass. The near term goals are 1) acoustically monitoring the rock kinematics due to effective stress change during the mine dewatering, 2) acoustically monitoring events due to construction and other activities needed to ready the mine for opening, 3) prepare the infrastructure for larger-scale monitoring as the facility ramps up.
In particular, the observatory will estimate the seismic parameters of events associated with the massive dewatering operation about to begin, excavation work, and various rock mechanics experiments, and estimate source kinematics caused by natural activity within or near the mine. Given the damage location of the event determined by the array, the rock mass can be back-excavated to find the source damage in the rocks. When found, a direct connection can be made between the damage process and seismic waves generated.
As the understanding of the physical meaning of the recorded seismic waveforms increases, the operators will be able to assess the rock mechanics health of the facility in the laboratory areas, as well as in areas of the underground that are closed off for extended periods of time, without active entering of the possibly dangerous space - underground and mine safety. In addition, the surrounding array can be used to greatly improve our ability to detect and characterize underground structures and activity - security and detection of underground facilities. This has been a goal of our military and border defense since the end of the Korean war.
As part of SDSTA, this observatory will provide a lifelong learning experience for all stakeholders - K-12 students and teachers, the hundreds of thousands of visitors passing through the Black Hills annually, under-represented groups in higher education, and the general student population. The observatory's outreach, through the South Dakota School of Mining and Technology, the South Dakota Science and Technology Authority, and near-by tribal colleges, will be deep and substantive. Two of these colleges already work closely with SDSM&T, and have become leaders in tribal science and mathematics education. The K-12 visitor programs will be coupled with summer teacher courses in which interested teachers are introduced to underground science at an appropriate level, providing them with the background they need to later explain the science to their students.
