# Science - Earthquakes

### 32 terms by Owlturtle

#### Study  only

Flashcards Flashcards

Scatter Scatter

Scatter Scatter

## Create a new folder

### seismology

the study of earthqakes

### elastic rebound

the sudden return of elastically deformed rock to its undeformed shape

### seismic waves

a wave of energy that travels through the Earth, away from an earthquake in all directions.

### P waves

a seismic wave that causes particles of rock to move in a back-and-forth direction.

### S waves

a seismic wave that caues particles of rock to move in a side to side direction

### body waves

sesimic Wave that travel through the Earth's interior

### surface waves

move along Earth's surface, travel slower than S&P waves, are most destructive, produces up/down, back/forth, and around motions of the Earth's crust.

### seismograph

an instrument that records vibruation in the ground and determines the location and strenght of an earthquake

### seismogram

a tracing of earthquake motion that created by a seismogram

### epicenter

the point on the Earth's surface dricety above an earthquake starting point,or focus

### focus

the point along a fault at which the first motion of an earthquake occurs

### S-P time method

perphaps the simplest method by which seismologists find an earthquake epiceneter is the s-p the method.

### Richter magnitude scale

commonly called richter scale of measure the strength of an earthquake

### magnitude

the richter scale measure the ground motion from an earthquake and adjusts for distance to find its strength

### intensity

a measure of the drgree nto which an earthquake is felt by people and the amount of damage caues by the earthquake,if any,is caues intensity

### Mercalli Intensity Scale

a measure of the degree to which an earthquake is felt by people and the amount of damage caused by the earthquake, the intensity can range from I to XII

### earthquake hazard

is a measure of how likely an area is to have earthquakes in the future

### gap hypothesis

a hypothesis that a based on the idea that major earthquake is more likely to occur along the part of an active fault where no have occured for a certain period of time

### seismic gap

an area along a fault where relatively few earthquakes have occured in past

### retrofitting

a common way to retrofit an few earhquakes have occured in past

### mass damper

is a weight placed in the roof of a building motion sensors detect building movement during an earthquake and send messages to a computer then signals control in the roof to shift the mass damper to counteract the building's movement

### active tension system

work much like the mass damper system in the roof sensor notify a computer activater devices to shift a large weight to counteract the movement

### base isolator

act as shock absorbers durging an earthquake.They are made of layers of rubber and steel wrapped around a lead core.Base isolator absorb sesimic waves,preventing them from traveling through the bulding

### cross braces

are place between floors the braces counteract pressure that pushed and pulls at the side of a building during an earthquake

### flexible pipes

help prevent waterline and gas line from breaking engineers design the pipes with flexible jonts so that the pipes are able to twist and bend without breaking during an earthquake

### how to calculate an epicenter . . .

scientists calculate the difference between arrival times of the P waves and S waves.

### transform boundary

the boundary between tectonic plates that are sliding past each other horizontally.

### convergent boundary

the boundary formed by the collision of two tectonic plates.

### divergent boundary

the boundary between two tectonic plates that are moving away from each other.

### reverse fault

when rocks are pushed together by compression reverse faults often form.

### strike-slip faults

form when opposing forces cause rocks to break and move horizontially.

### normal fault

when rocks are pulled apart because of tension.

Example: