Seismic Activity

Question 1

What are the characteristics of seismicity?

Answer 1

Ground shaking, large magnitude quakes.

Question 2

How is seismicity created?

Answer 2

It is created on plate boundaries, where friction between plates from subduction causes seismic activity.

Question 3

Name the 5 main hazards of seismic activity.

Answer 3

Earthquakes, shockwaves, liquefaction, landslides, tsunamis.

Question 4

What are the reasons for Tsunamis?

Answer 4

Landslides causing huge displacement of water, lava landslides and landslide from dormant volcano. Plate margins - Slab pull goes so far that it causes the plate above to flip up and send the large wave.

Question 5

Name the characteristics of a Tsunami.

Answer 5

Huge fast waves, hard to detect.

Question 6

How is seismic activity measured?

Answer 6

Richter Scale - The earthquake’s magnitude is determined using the logarithm of the amplitude (height) of the largest seismic wave calibrated to a scale by a seismograph.
Mercalli Scale - The Mercalli Scale is based on observable earthquake damage.

Question 7

Frequency of hazards.

Answer 7

Small earthquakes occur all the time on plate boundaries, with many not being felt. Large earthquakes on the other hand are far rarer but when they do occur many of the other hazards that come with it also occur.

Question 8

Predictability of hazards.

Answer 8

Can be fairly predictable as if there is a lot of small unexpected seismic activity it is likely a larger event will occur.

Question 9

Challenges of dealing with these hazards

Answer 9

Tsunamis can devastate whole regions and cities, such as Sendai and the Tokuhu region in Japan. Furthermore, landslide can do lots of local damage. Earthquakes themselves are also highly destructive, with buildings being at risk if not aseismic, as seen with what has happened in the Turkey/Syria earthquake