1.5 Flashcards
What does Richter Scale measure and scale type
Earthquakes
0-9 scale
Absolute scale - wherever earthquake recorded, measures same on Richter scale
Richter Scale Overview
Measurement of amplitude of wave produced by earthquake
What does Mercalli Scale measure and scale type
Earthquake
I-XII
Relative scale - People experience different amounts of shaking in different places
Mercalli Scale Overview
Measures experienced impacts of earthquake. Based on series of key responses, people awakening, movement of furniture and damage to structures
What does Moment Magnitude Scale (MMS) measure and scale type
Earthquakes
0-9
Moment Magnitude Scale (MMS) overview
Used to describe earthquakes in terms of energy release.
Magnitude based on ‘seismic moment’ of earthquake, which is calculated from amount of slip on fault
What does Volcanic Explosively Index (VEI) measure and type of scale
Volcanic eruption
0-8
Like MMS, is logarithmic
Volcanic Explosively Index (VEI) overview
Relative measure of explosiveness of a volcanic eruption
Calculated from volume of products (ejecta), height of eruption cloud and qualitative observation
Logarithmic Scale
An increase of one index indicates an eruption that is 10x as powerful
Problem with hazard scales
Do not take into account duration of hazard, physical exposure or vulnerability and resilience of affected communities.
Solution to the problems of from hazard scales
Hazard profiles
What are Hazard Profiles
Diagram showing main characteristics of different types of tectonic hazard
Could be developed for a single hazard, or show multiple-allows comparisons to be made
Positive of Hazard Profile
Help government and other organisations develop disaster plans
