Tectonics - EQ3 Flashcards
What is prediction?
Knowing when and where a natural hazard will strike on a spatial and temporal scale that can be acted on meaningfully in terms of evacuation
Forecasting
A percentage change of a hazard occurring - less precise than prediction
Seismic gaps
Areas that have not experienced an earthquake for some time and are ‘overdue’
How are earthquakes predicted?
They aren’t but seismic gaps can point to areas of high risk
How are volcanoes predicted?
- Sophisticated monitoring equipment
- Tiltmeters
- Gas spectrometers
Sophisticated montitoring equipment
Measures changes as magma chambers fill and eruption nears
Tiltmeters and strainmeters
Record ‘bulging’ as magma rises
Seismometers
Record minor earthquakes indicating magma movement
Gas spectrometers
Analyse gas emissions which can point to increased eruption likelihood
Why is the death toll from volcanic eruptions low?
Vastly improved prediction of events
How can tsunami’s be predicted?
- Earthquake-induced tsunami’s can’t be predicted
- Seismometres can tell an earthquake has occurred and locate it
- Ocean monitoring equipment can detect tsunami in the open sea
- This information can be relayed to coastal areas, which can be evacuated
What is the issue with predicting natural hazards?
- Cost of technology means that developing countries can’t afford volcanic and tsunami monitoring and warning systems
- Hard to reach isolated/ rural areas with effective warnings
What is the purpose of the Hazard Management Cycle?
The different stages of managing hazards in an attempt to reduce the scale of disaster
Response
Immediate help in the form of rescue to save lives and aid to keep people alive, emergency shelter, food and water
Recovery
Rebuilding infrastructure and services, rehabilitating injured (physically and mentally) people and their lives
