1.5A - Tokohu Flashcards
Scales that measure hazards based on intensity
Mercalli Scale
Tsunami Intensity
Scales that measure hazards based on magnitude
Moment Magnitude Scale
Volcanic Explosivity Index
(Richter Scale)
What does Logarithmic mean?
A scale that increases proportionally to the event
EG - A volcanic eruption of 4 is 10x smaller than one of 5 on the VEI
What is used to calculate the VEI of an eruption?
3 things
Volume of product released
Height of the eruption cloud
Qualitative observations
Which scale in more accurate in measuring earthquake magnitude, the Richter Scale or the Moment Magnitude Scale? Why?
The Moment Magnitude Scale - it measures the energy released by all shockwaves, not just P and L waves, as well as the area of the rupture and movement
Why is the Mercalli Scale described as a relative scale?
It measures the experienced impacts of an earthquake, meaning it is fairly subjective
What affects the impact of a hazard event?
The event itself - size, duration
The environment it happened in
Why is the Richter Scale defined as an absolute scale?
All earthquake events are measured using the same parameters, meaning if 2 earthquakes that were the same happened in 2 different locations, they would be the same
What are some of the key responses used in the Mercalli Scale?
The number of people who were woken by the event
The movement of furniture
The damage to structures
What is used to calculate the Moment Magnitude Scale?
The energy released - things like the amount of slip in the fault, or the total area affected are also used
Define intensity
The amount of damage created by a tectonic event or other hazard
Define magnitude
The amount of energy released by a tectonic event
What percent did GDP drop by following the earthquake?
3.5%
What magnitude was the earthquake?
9.1mW - 4th largest in the world
How long was it before the Shinkansen Bullet Train was back in service?
1 day
