Measuring rock deformation

GEOXTM members and Sanford Lab staff set up a stress test on the 4100 Level.

The goal of GEOXTM is to create the world's largest, deepest network of underground fiber-optic strain and temperature sensors and tiltmeters to measure the movement of rock systems in the underground laboratory. The multidisciplinary and multi-institutional collaboration is led by geologist Herb Wang of the University of Wisconsin. Wang's colleagues includes geoscientists, engineers and technicians from throughout the world. GEOXTM is sponsored by the Geomechanics Program of the National Science Founcation.

The first tiltmeters of the "Hydrostatic Level System" were installed in January 2009 to establish baseline measurements. Tiltmeters are sophisticated, highly sensitive instruments, but the operate on the same principle used in simple bubble levels. That is, water seeks a level. The tiltmeters installed in 2009 were the same type developed by Jim Volk for the Tevatron particle accelerator at Fermi National Accelerator Laboratory. GEOXTM arrays at the Sanford Lab include instruments on the 2000, 4100 and 4850 levels.

The GEOXTM research team also is developing a new method for measuring deformation and temperature changes in rock. The devices are called FROSTS (Fiber optically instrumented ROck Strain and Temperature Strips). Each consists of a 6-foot-long strip of stainless steel with fiber-optic strain and temperature sensors attached at 1-foot intervals. The FROSTS are grouted into boreholes drilled into the rock. Strain and temperature are measured using a laser light signal sent down the fiber optic cable to sensors.
  • GEOXTM broadcasts from 'Studio 4100L'

    April 3, 2012

    University of Wisconsin geologist Herb Wang began a videoconference presentation Thursday with a tongue-in-cheek greeting: “Welcome to Studio 4100L in the Sanford Underground Research Facility.”

    Wang was speaking from the GEOXTM experiment site on the 4100 Level. He was addressing the Deep Underground Research Association (DURA), which was meeting at Fermilab in Batavia, Ill. Multimedia Specialist Matt Kapust and Systems Software Specialist Leif Hage worked with technical staff at Fermilab to set up the videoconference.

  • When the earth moves, the Sanford Lab listens

    April 1, 2010

    Three research groups at the Sanford Underground Laboratory at Homestake detected recent earthquakes in Japan, Chile, Haiti and Mexico -- as well as last September's tsunami in the Pacific Ocean. The data illustrate how the Sanford Lab, as the nation's Deep Underground Science and Engineering Laboratory, will play a major role in future explorations into the structure of planet earth.