Natural Hazards Flashcards
What is a hazard
The threat of substantial impact upon life or damage to property that can be caused by an event, they occur in physical environment
What is a natural disaster
Occurs as a result of a hazard. Causing widespread disruption
What is risk
The exposure of people to a hazardous event
What is vulnerability
The geographical conditions that increase the susceptibility of a community to a hazard or to the impact of a hazard event
Why do people put themselves at risk from natural hazards
No choice
Rich soils
May think low risk
Have the money to protect themselves
Uneducated
What affects vulnerability of a place to a hazard
How close place is to risk zone, experience and built env
What is adaptation
Communities + people living with hazard events. They adjust living conditions
What is mitigation
Actions aimed at reducing the severity of an event and lessening impacts
What is management
Dealing with or controlling things or people
Risk sharing (community preparedness)?
Prearranged measures that aim to reduce loss of life and damage via education and awareness programmes
What is prediction
Using tech to predict when an event is going to happen to send out warnings
What is fatalism
A view that people cannot influence or shape the outcome. Put in place very little prevention. Often religious
What determines the severity of a hazard
Duration, magnitude, predictability, regularity, frequency, special concentration, areal extent, number of hazards
What is the disaster/risk management cycle?
Pre disaster, response, post-disaster
Preparedness, response (short term) recovery (long term response) mitigation (rebuilding) review
What does the disaster/ risk management cycle illustrate
Ongoing process which govs, societies and businesses plan for and reduce the impacts of disasters, react during, and take steps to recover after. Appropriate actions at each point reduces vulnerability during the next cycle
What is the park model
Aims to show the effects of a hazard on quality of life over a sequence of time. By analysing and impending hazard in advance, they can see a normal progression through a disaster.
What are the positives and negatives of the disaster cycle
Clearly addresses each stage of a hazard making it easier to manage
It’s a cycle, can be reviewed it identifies the need for constant management for people to be safe
Negatives is that it’s basic and all hazards r different
What are the stages of the park model
Normality, hazard event, relief, rehabilitation, reconstruction
What are positives and negatives of the park model
Makes links between hazards and how it affects the quality of life
Gives a time frame on reacting and dealing with a hazard
Basic, no account of varying capacity to respond
What’s the plate tectonic theory?
Continents fit togetehr like a jigsaw, backed up by fossils, rocks and mountain ranges fitting togetehr
Sea floor studies- striped pattern on either side of mid oceanic ridge from paleo magnetic phases. Crust split and ocean floor moved apart with rock created in the gap
What’s the crust
0-70km thick . Continental is old and less dense
Oceanic is younger but more dense
What’s the mantle
2900km thick
Most ofantle (asthenosphere) is semi molten
What’s the inner and outer core
Over 5000°c
Outer is liquid but inner is solid and made of iron and nickel
How do convection currents work?
Magma and hot rock heats and rises due to primordial and radiogenic heat from the core. Rises and cools and sinks. Upward limb causes constructive plate boundaries thr downwards causes destructive
What is ridge push
Molten magma rises and heats the lithosphere it expands and causes a slope. The rock formed by magma cools then gravity pulls the rock down the asthenosphere . The rock drives the plates to move
What is slab pull
Subduction boundary the denser plate subducts. As the edge of the plate cools it continues to sink pulling the rest of the plate along with it. This force is slab pull
How does a destructive plate margin form
Denser oceanic plate forced down underneath the other, marked on surface by a trench. Friction causes tsunamis and earthquakes. The water from the crust goes into the mantle and as the plate heats up the water is liberated, the melting point in the mantle decreases and the plate partials melts in the Benioff zone. It produces magmas which rises and explodes as a volcano
When did mt nyiragongo erupt?
2002
What caused the my nyiragongo eruption?
Months of increased earthquakes, 13km fissure opened. Basaltic lava exited from 3 main vents
How many people died as a result of mt nyiragongo
147
How much of Goma was destroyed in drc
One third and covered runway
How many people were left homeless in drc
120,000
How many people were dependent on aid in drc
350,000
What was a secondary effect of eruption in drc
Sulpuherous lava entered lake kivu and contaminated water supplies- cholera
What were the immediate responses
Red alert
2 days later humanitarian aid
$15 mill costs
When was the Iceland eruption
2010
What plate margins were involved in the Iceland eruption?
Constructive. North American and Eurasian
When was the Japan earthquake and what plate margin was involved
Destructive, Eurasian and pacific, 1995
What magnitude was was the Kobe earthquake
7.2
How many people died in the Kobe earthquake
6434
How many people were injured in the Kobe earthquake
35000
How high did the ash plume go into the air?
11,000m
How many farms were destroyed in the Iceland eruption
20
What were the secondary effects of the Iceland eruption
£102 million lost tourism
95,000 flights cancelled worldwide
£2 bill lost in airlines
What were the immediate responses to the Iceland eruption?
30 min warning texts
700 evacuated due to ice cap melting
Seismic monitoring, and gps where they measured that the crust had moved 3cm
What were the long term responses to the Iceland eruption
Dredging to remove ash from rivers
Who paid for the long term responses of the Iceland eruption
Icelandic gov
How many buildings were destroyed in the Kobe earthquake
102,000 and they were made of wood
What fell that injured or killed people in the Kobe earthquake
Heavy roofs for typhoon season
What were the secondary effects of the Kobe earthquake
1 million left without water which led to fires spreading
300,000 homeless
Liquefaction
$220 million costs
What were the Imedia the responses to the Kobe earthquake
Retrofitted earthquake proof buildings from 1980
Phone connections were maintained free of charge by Motorola
Japanese gov criticised as didn’t want help from other nations
What were the long term responses to the Japanese earthquake
$120 mill reconstruction costs
Smart meters to cut off electricity and gas
6 months for recovery
