earthquake energy

…plate tectonics

body waves

Travel through the earth (travel through rock).

p waves

compressional waves, “primary”. first to arrive. can travel through anything.

s waves

move the ground up and down/side to side.

surface waves

Travel through only through the surface, when body waves hit the surface this happens.

L Waves

left and right; circular path left and right. moves faster

R waves

up and down; particles underground follows a circular path up and down. “ocean waves” back and fourth.

Richter Scale

We look at SP time vs. the amplitude of the largest LR wave. Log scale.

Moment Magnitude

Geologists mostly use Moment Magnitude scale, which also taken into account the rock type.

Shaking Intensity

Unlike Richter Scale, shaking intensity also accounts for bedrock type:

• hard rock site: smaller shake since waves moves through and dissipate
• soft soil: waves slow down, and thus actually more intensive shaking