Measuring hazards

Question 1

What does the richter scale measure?

Answer 1

Magnitude of earthquakes and the amount of energy released during on. Increases in a 10-fold amplitude It does this by measuring seismic waves produced by an earthquake using a seismograph.

Question 2

Positives of the Richter scale

Answer 2

-It’s simplicity
-It is an immediate assessment
-Been used for decades so it has historical data
-It is an immediate assessment
-Helps to raise awareness of seismic risk

Question 3

Negatives of the Richter scale

Answer 3

-Limited at high magnitude
-May not accurately represent the intensity of the shaking experience
-Scale doesn’t consider factors such as depth and duration
-Other scales have become more widely used.

Question 4

The Modified Mercalli scale

Answer 4

Measures the intensity of an earthquake’s effect on people, structures and the earth’s surface rather than the energy released.
Ranges for I (not felt) to xII
Accesses how strongly the earthquake shakes the ground at specific locations.It evaluates observable effects based on human observations and structural damage.

Question 5

Positives of the Modified Mercalli scale

Answer 5

-Can be used in both smaller and larger earthquakes.
-Helps with damage estimations
-Can be used to understand the impacts.

Question 6

Negatives of the Modified Mercalli scale

Answer 6

-Opinion based
-It doesn’t access any physical information such as magnitude
-Can’t be used to help predict any future earthquakes.

Question 7

What is the Moment magnitude Scale?

Answer 7

Scale based on the total moment release of the earthquake, a product of the area of the fault that slipped, the distance the fault moved, and the rigidity of the surrounding rocks.
Its always shown as a whole number (1-10) due to logarithmic scale.

Question 8

Positives of the Moment magnitude scale

Answer 8

provides an estimate size of an earthqauke

Question 9

Negative of the Moment magnitude scale

Answer 9

Bad at measuring smaller earthquakes

Question 10

What is the VEI

Answer 10

Measures the size of volcanic eruptions. It is dependant on how much volcanic material is thrown out and how long the eruption lasts.

Question 11

Positives of VEI

Answer 11

-Can predict the relative impact volcanoes might have on
-It can help scientists communicate hazards

Question 12

Negatives of VEI

Answer 12

-Not useful if the eruption is effusive
-It doesn’t take into account the power output of the eruption
-difficult to measure the amount of pyroclastic flow.