Velociraptor truck and trailer

Velociraptor is the USGS Pacific Coastal and Marine Science Center's Seismic-Wave Velocity Explorer. Velociraptor measures how much the ground it’s on will shake during an earthquake, and determines whether the ground is likely to liquefy. It does this by measuring ground “stiffness”—the tendency of the ground to resist deforming (changing shape) when subjected to forces like earthquake shaking. Here, Velociraptor is shown measuring ground stiffness at the Gold Hill sensor array, Parkfield, California, in 2008.