ERTH 2415 Lecture Notes - Lecture 5: Seismic Wave, Hypocenter, Seismogram
8 Feb 2019
School
Department
Course
Professor
Document Summary
Recall: in the asthenosphere and mesosphere, there are hot convection loops that carry warm magma closer to the cooler, lithosphere. These loops drag the lithosphere plates and can open a crack in the seafloor (at a spreading center) where new crust is formed as the lithosphere gets recycled Lecture objectives: to understand how energy is released during an earthquake, to describe the characteristics of seismic waves, to locate the epicenter and estimate the magnitude of an earthquake from seismogram measurements. Earthquakes are caused by sudden movements along faults. Stress from deformation forces build up until rocks fail. Energy is then released as seismic waves in a short period of time. Fault = fracture across which two blocks of rock move relative to each other. Faults are found in several tectonic environments prone to large earthquakes: Megathrust faults: the boundary b/w the subducting and overriding plates.
