Class+notes+II

=Earthquake Unit Class Notes=

__Earthquake__ – vibrations in the Earth caused by a sudden release of energy, usually the result of movement of rocks at a fault line.

“P” stands for primary Faster than a S-wave Moves the ground up and down Causes minimal damage

“S” stands for Secondary Slower than a P-wave (not slow!) Moves the ground side to side Causes most of the damage

Seismograph – instrument that detects and records Earthquake waves

Seismogram – the paper that Earthquake waves are recorded on

Seismologist – scientist that studies Earthquakes

Focus – The place under the ground where the energy of an Earthquake is released

Epicenter – the point on the Earth’s surface above the focus of an Earthquake

__Theory of plate tectonics__: The theory that the lithosphere moves as “plates” on a plastic-like asthenosphere Major Earthquake zones of the Earth: 1. Circum-pacific belt (Ring of Fire) 2. Mid Atlantic Ridge 3. Mediterranean – Himalayan belt

Three types of plate boundaries: Convergent plate boundary Plates colliding Examples: 1. Subduction zones 2. Himalayan mountains

Divergent plate boundary Plates separating Example: Mid Atlantic ridge

Transform fault Plates sliding past each other Example: San Andreas Fault