HPWREN sent around an interesting link from NEES@UCSB about the Magnitude 7.2 earthquake in Baja, California on April 4, 2010. The story is by Hank Ratzesberger, Network for Earthquake Engineering Simulation (NEES).
Caption for image above: Ground and downhole acceleration was recorded at depths of 5.5, 8.5, 30 and 100 meters. The Wildlife and other sites operated by NEES@UCSB are among a handful of sites with dense instrumentation at strategic soil layer depths. Highly instrumented and thoroughly characterized, the sites provide a laboratory to test modeling of soil and seismic wave properties.