GEOL 412 Lecture Notes - Lecture 5: Seismic Wave, Seismic Refraction, Seismic Source

• School: College of Charleston
• Department: Geology and Environmental Geosciences
• Course: GEOL 412
• Professor: Jaume'

Document Summary

Seismic energy radiates in all directions from a seismic source. Seismic data interpretation involves determining time it takes for waves to go different distances; i. e. , determine seismic velocity. However, seismic wave energy changes direction as it crosses boundaries of materials with different velocities. Seismic waves are usually considered to start at a point (impact) and then spread out from there. An important part of seismic interpretation is keeping track of where the seismic energy is going and how long it takes to get there. Any point on a wave front can be considered a point source that sends out energy. Wave front at time t2 is tangent to intersection of all waves coming from point sources along wave front at time t1. If a material has constant seismic velocity, the fastest distance between 2 points is a straight line. Reflection at a boundary some seismic energy reflects off a boundary between materials with different seismic velocities.