JGE378H5 Lecture Notes - Lecture 3: Induced Seismicity, Hydraulic Fracturing, Rock Burst
Document Summary
Earthquake triggers: trigger: sets o a mechanism or induces an event to occur, natural triggers for earthquakes: Anthropogenic triggers for earthquakes: induced seismicity: nuclear bomb testing, mining-related explosions and changes in underground stress regimes: rock burst. Filling of arti cial reservoirs: weight + lubrication: pumping liquids into the ground under pressure liquid hazardous waste disposal, fracking or hydro-fracking for oil extraction, human-induced earthquake are usually smaller and have di erent seismic characteristics. Intersection of internal and external processes: internal processes in uence: Mantle convection drives plate motion: hot rock (low density) rises from depth and cool rock (high density) sinks from the surface, hot, mobile mantle + thin, cool, brittle lithosphere. Intraplate: middle of the plate, plate boundaries, divergent (plates moving apart, convergent (plates moving together, transform or strike-slip (plates moving horizontally past each other) Intraplate: not on a plate boundary: geologically quiet, with some exceptions volcanic hot spots e. g. , hawaii, intraplate earthquakes, e. g. , new madrid.
