Study GuideGeology–Earthquakes1. Monitoring EarthquakesEarthquakes may happen suddenly, but scientists have powerful tools to study them. By carefullymeasuring seismic waves, geologists can figure outwherean earthquake happened,how deepitwas, andhow strongit was. Let’s break this down step by step.1.1 Seismometers and SeismogramsEarthquakes are detected using an instrument called aseismometer.A seismometer contains a suspended, pendulum-like mass that stays as still as possible while theground moves around it.Here’s how it works:•When theground shakes, the frame of the seismometer moves.•The suspended mass moves much less.•This difference in motion is recorded.The recording device is called aseismograph, and the record it produces is known as aseismogram. A seismogram looks like aseries of wavy or “squiggly” lines that show how the groundmoved during the earthquake.Seismograph stations all over the world can record waves from the same earthquake. By comparingdata from different stations, scientists can calculate:•thelocationof the earthquake,•itsdepth, and•itsstrength.These comparisons can also give clues about the types of rocks the seismic waves traveled through.Preview Mode
This document has 17 pages. Sign in to access the full document!