earthquakes

Question 1

seismic gap theory

Answer 1

A seismic gap is a segment of an active fault known to produce significant earthquakes, that has not slipped in an unusually long time when compared with other segments along the same structure. Seismic gap hypothesis/theory states that, over long periods of time, the displacement on any segment must be equal to that experienced by all the other parts of the fault.[1] Any large and longstanding gap is therefore considered to be the fault segment most likely to suffer future earthquakes.

Question 2

gas measurement

Answer 2

measuring radon gas, increase then sudden decrease immediately before earthquake occurs

Question 3

deep earthquake

Answer 3

300-700km

Question 4

intermediate earthquake

Answer 4

70-300km

Question 5

shallow earthquake

Answer 5

0-70km

Question 6

epicentre

Answer 6

point on earth surface above focus

Question 7

focus

Answer 7

origin of earthquake

Question 8

stress:

Answer 8

a force that can cause a change in an object or a physical body

Question 9

strain:

Answer 9

strain is the change in the form or shape of the object or physical body on which stress is applied.

Question 10

density of earth

Answer 10

5.5g/cm^3

Question 11

density of surface rocks

Answer 11

2.7 – 2.9 g/cm^3

Question 12

density of inner core

Answer 12

12-15 g/cm^3