EPSC 201 Lecture Notes - Lecture 7: Epicenter, Elastic Energy, Seismic Wave
26 Jan 2017
School
Department
Course
Professor
Document Summary
On a sloping fault, crustal blocks are classified as: footwall (block below the fault, hanging wall (block above the fault) The fault type is based on relative block motion: normal fault. The hanging wall moves down relative to the footwall. Results from extension (pull-apart or stretching: reverse fault. The hanging wall moves up relative to the footwall. The slope (dip) of fault is steep: thrust fault. The slop (dip) of fault surface is much less steep. Common fault type in compressional mountain belts: strike-slip fault. One block slides laterally past the other block. There is no vertical motion across the fault. The fault surface, however, is nearly vertical. Faults are found in many places in the crust: active faults ongoing stresses produce motion. Inactive faults motion occurred in the geologic past. A fault trace shows the fault intersecting the ground: displacement at the land surface creates a fault scrap. Not all faults reach the surface: blind faults are invisible.
