Refraction4_IRIS.mov

4th in Refraction Series from: www.iris.edu/hq/programs/education_and_outreach/animations .
Introduction to refraction. Seismic waves follow the same law of refraction at compositional boundaries. If the seismic wave velocity in the rock below a boundary increases,the waves will be refracted upward and speed up relative to their original path. If it passes across a boundary to a lower velocity layer, the wave will be refracted downward and slow down. Because velocity generally increases with depth in the mantle, the wave paths get bent until they reach a critical angle at which point, the waves return to the surface following a curved path upward. Sound is used to emphasize arrival times.

Category:

Science & Technology

Tags:

• refraction
• reflection
• earthquake
• animation
• boyd
• seismic
• curving
• path
• earth
• velocity
• sound
• tectonics
• science
• plate
• aesthenosphere
• lithosphere
• mantle
• crust