earthquakes

Question 1

Define earthquake.

Answer 1

A sudden shaking of the ground

Question 2

Where are 90% of the earthquake happening at?

Answer 2

Circum-Pacific Belt
Alpine-Himalayn Belt

Question 3

Define the three characteristics of an earthquake.

Answer 3

Seismic waves: energy transmitted from the focus in all directions.
Epicentre: The point on Earth’s surface directly vertical above the focus.
Focus: The point where crust fractures and release seismic waves

Question 4

Complete the sentence: “the nearer to the focus…”

Answer 4

…the higher intensity of the earthquake, as seismic waves decrease as it travels.

Question 5

3 classes of focus?

Answer 5

0-70: shallow focus
70-300: medium focus
300+: deep focus

Question 6

How is an earthquake formed?

Answer 6

…the rock experiences stress.
Energy is built up and stored in the rock. When the stored energy exceeds the strength of the rock, the rock breaks. Stored energy is released.

Question 7

Measures of earthquakes?

Answer 7

Richter Scale, Modified Mercalli Scale

Question 8

What is used as a measuring unit of Richter Scale? What does it indicate?

Answer 8

Seismograph is used to measure amount of energy released in earthquake. Indicate waves’ energy.

Question 9

What is used as a measuring unit of Modified Mercalli Scale? What does it indicate?

Answer 9

Degree of damage the earthquakes has caused is used to measure. Indicates intensity of earthquake.