GEOL 106 Final: Lecture 9
22 Jan 2016
School
Course
Professor
Document Summary
Understanding the hazard: where do earthquakes occur? (continued: there are two types of body waves. P-waves (primary; pull-pull; back-and-forth) cause compression and rarefaction. S-waves (secondary; shear) cause movement perpendicular to the direction of the wave: the velocity of seismic waves is the elasticity / density. Velocities change when waves move into different material. K is the compressibility modulus (eg, stress needed to compress). The shear modulus (eg, stress needed to change the shape). Is the density of the material the waves are going through. P-waves (at 6 km/s) are always faster than s-waves (at 3 km/s). A p-wave that hits toronto (250 km away from kingston) hits kingston within 1 minute! S-waves move the ground more than p-waves, causing more damage underground.
