Earthquake

what is earthquake

What waves do earthquake make

Locating earthquake

How is an earthquake's energy measured

Tsunamis

How can people prepare

A sudden movement of earth curst

a suddenly slip of crust

earthquake's focus

earthquake's epicenter

in the ground

the point on the ground

happen along the boundaries of earth's tectonic plates

primary wave

secondary wave

surface wave

fastest

slowest

half speed of primary

back and forth

up and down

move in solid and liquid layers

only move in solid layer

travel along earth's surface

cause most damage

seismometer

difference between the arrival of P wave and S wave

need three station to know the exact location

Magnitude

Richter scale(芮氏規模)

the amount of energy released

30 times per level

7.6/ 5.6- 900 times bigger

move 500-1000km per hour

wave isn't very high

mostly happens at 6.5 richter scale

can be predict

can send warning to every people

building stracture

know what to do when earthquake happen

secure objects that might fall

know the safe spot at your home

kitchen counter

a sturdy table