Ultimately, studies such as these may lead to refined estimates of how often and how predictably a given fault is likely to rupture, the researchers believe. Li and Vidale plan to continue to monitor the Johnson fault, trying to determine if the rate of healing is constant over time, or accelerates or decelerates, to develop their understanding of the faulting and healing process. Other collaborators on the Johnson Valley work were Keiiti Aki, holder of USC's W.M. Keck Foundation Chair in Geological Sciences, graduate student Fei Xu of UCLA and geophysicist Thomas Burdette of the Menlo Park office of the U.S. Geological Survey. The National Science Foundation and the USGS funded the research. The Role of Water Theorists have proposed many ideas for the sequence of events leading to an earthquake, from simple theories of dry rock surfaces rubbing against one another to more complicated scenarios in which water with dissolved minerals is present.
Water percolates into a rupture zone after a quake.
According to the scientific team, theory predicts that the more fluid present in a fault zone, the faster healing processes would proceed, because water in the formation tends to lubricate motion of rock masses in the fault. An increase in water pressure may push the sides of the fault apart, encouraging the fault slip that makes the Earth quake. We are monitoring whether the amount of fluid increases after a quake. USC geophysicist Yong-Gang Li with research assistants on the Johnson Valley fault in the Mojave Desert.