GEOL 303 Lecture Notes - Lecture 21: Return Period, Active Fault, Radon
Document Summary
Seismic gaps - segments on an active fault where no significant earthquakes have been recorded, result to either: Fault creep (consent fault motion = no threat) Fault is locked in place (no fault motion - stress continues builds up with time and is eventually released in an earthquake. Asperites - such areas occur along stable rough spots or areas of high ruction. Recurrence interval - average length of time between earthquakes of a given magnitude. However, this prediction took longer than expected, with a 6. 0 m earthquake finally occurring in 2004, Rocks under stress will expand (dilate) in volume until eventually reaching a point of rupture, where the rock breaks and an earthquake ensures. Dilatancy - a precursor and potential predictor of earthquakes. Stage 1 (micro-crack formation) > stage 2 (dilation, expansion) > stage 3 (influx of water) > earthquake. Cattle, horses, and sheep refuse to enter their corrals.
