EPS C20 Lecture Notes - Lecture 9: Computer Simulation, Pacific Plate, Plate Tectonics

• School: Berkeley
• Department: Earth And Planetary Science
• Course: EPS C20
• Professor: Richard Allen

Document Summary

Building up to an earthquakeon the hayward fault. Pacific-north america boundary slip rate: 50 mm/yr. Hayward fault accounts for 20% of total plate motion. The great san francisco earthquake (until 1906!) Number of quakes to offset strawberry creek: ~170. Earthquake rate: 1 every ~190 yr ago. From the trench: last major quake was between 1665 & 1776 ~300 years. No big quakes since 1868 151 years & counting. Earthquakes on the hayward fault all estimated to be m6. 3 or greater. The sudden release of built-up stress along faults by earthquakes. Stress builds up due as tectonic plates move past one another. Friction along the fault prevents slip, elastic deformation instead. This theory does not explain all our observations. Steady progression on hayward fault not associated with an earthquake. Different fault behaviors: locked vs. creeping faults. Cut by the fault - and creeping. Even along creeping faults, the reality is somewhere in between . Creep relieves strain and makes earthquakes smaller.