EPS C20 Midterm: Midterm #2 Review
17 Nov 2020
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Document Summary
Pacific-north america boundary slip rate: 50 mm/yr. Hayward fault accounts for 20% of total plate motion. From the trench: last major quake was ~300 years ago. Earthquakes on fault all estimated to be m6. 3+ Elastic rebound theory: the build up of stresses on a fault leading to an earthquake. At the plate boundaries, elastic deformation accommodates the strain. When the stress on the fault exceeds the fault strength, the fault slides suddenly in an earthquake. Only release strain in earthquakes -- accumulates strain for the release of an earthquake. Release plate tectonic strains without the need for earthquakes. Many faults have both locked & creeping behavior. Hayward fault is partially locked & partially creeping. Memorial stadium is creeping at 4 mm/yr or very little seismic hazard. Aseismic creep : accumulated strain gets released continuously at low rate = no. Earthquake : sudden release of large amount of accumulated strain = large. Differential gps: accuracy of a few millimeters.
