Scissor-Jack" Crackmeter (VW)



In late 2009 the U.S. Geological Survey (USGS) and National Park Service (NPS) joined into a collaborative research project to investigate the deformation of large, vertically-oriented, granite slabs in response to thermal heating and solar radiation. The goal of the project is to quantify how partially detached rock slabs respond to these stresses and whether or not they might act as precursors to rock falls that are common in many areas of the United States. The field site consisted of a 14 m tall granite slab partially detached by an 8-15 cm gap to a near-vertical cliff.