Cooperative Institute for Research in Environmental Sciences at the University of Colorado Boulder

Daniel Gittins

Not all faults slip solely in earthquakes – some have measurable offsets which cannot be attributed to earthquakes thanks to a process called creep. Fault creep was first identified over 60 years ago, and since then, many different fault behaviors have been identified. A particularly interesting observation is that creeping faults do not accumulate slip uniformly in time but instead in bursts of slip known as creep events. Creep events are typically a few hours to days in duration, occur every few weeks to months and have displacements of a few millimetres. These bursts of slip have been observed to occur on faults in California (e.g., San Andreas, Hayward and Calaveras Faults) as well as the North Anatolian Fault, Turkey. Despite knowing about these creep events since the late 1950s, we still do not know what causes them to nucleate or how they relate to other slow earthquake processes. Dan will work with Roger Bilham to investigate active creeping faults in California and beyond, using and developing a variety of geodetic instruments to understand the nucleation of creep events and determine how their moment and duration scale with one another.