The Challenge of Natural Hazards Flashcards
Definition of a natural Hazard
Natural hazards are extreme natural events that cause loss of life, damage to property or disrupts human activity
What are the factors affecting hazard risk
Vulnerability, Capacity to Cope, Nature of natural hazards
What is the plate tectonic theory
- The crust is the outer layer of the earth.
-The crust is broken into tectonic plates which are moved by convection currents. - Mechanisms such as slab pull and ridge push are believed to move the plates.
What is a destructive plate margin?
Where two plates move towards each other e.g Along the west coast of America.
What is a Constructive Plate margin?
Where two plates move away from each other e.g mid-Atlantic ridge.
What is a conservative Plate margin?
When two plates move sideways past each other at different speeds, e.g. The west coast of America.
Physical process in destructive plate margin to form volcano
The oceanic plate moves down into the mantle and is melted, magma then rises and erupts forming a volcano.
Physical process in destructive plate margin to form Earthquake
Tension builds up as one plate gets stuck as it moves down past the other into the mantle.
Primary and secondary effects of a Tectonic hazard
Primary:
-Deaths and injury
-Buildings damaged and destroyed
-People made Homeless
Secondary:
-Aftershocks causing more damage
-Fires in collapsed buildings
-Electricity and phone services disrupted.
Immediate and Long-term responses of a tectonic hazard
Immediate:
-Evacuate people before eruption
-Provide food and shelter for evacuated people.
-Rescue anyone cut off by damage to roads or bridges.
-Foreign governments send aid workers.
Long-term:
-New settlements built and buildings repair
-Repair and reconnect infrastructure
-Boost economy by using tourism for volcano site.
What is the case study for Tectonic hazards?
L’Aquila, Italy and Gorkha, Nepal.
Facts about the Gorkha earthquake
-7.8 magnitude
-9000 deaths
-8 million people affected
-Epicentre only 81km from Kathmandu capital city.
-Avalanches hit everest climbers
-Oxfam provided secondary aid.
Facts about the L’Aquila Earthquake
-6.3 on the Richter scale
-309 deaths
-3:32 AM whilst people were sleeping
-$1.1m damage.
-60 miles North West of Rome
-Lack of housing afterwards pushed prices higher
Why do people continue to live in areas at risk from a tectonic hazard?
-Family and friends, soil around volcanoes is fertile which attracts farmers, Employment.
How does monitoring reduce risk of a tectonic hazard.
Seismometers monitor earth movements, allowing governments to warn people
How does prediction and planning reduce the risk of a tectonic hazard?
Prediction: Monitoring movement of tectonic plates scientists can predict what areas should prepare.
Predicting when a volcano is going to erupt gives people time to evacuate reducing deaths.
Warm air ______
Rises
Rising air causes a ___ pressure belt
Low pressure belt