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
Cool and falling air creates a ____ pressure belt
High pressure belt
High pressure belt =
(Rainfall)
Cloudless skies and low rainfall
Low pressure belt =
(Rainfall)
Cloudy skies and High rainfall
What are trade winds
Surface winds blowing towards the equator
What are the conditions needed for tropical storms?
Sea Temperature = 27C or higher, never along the equator and Low wind shear.
Global distribution of tropical storms
Between tropic of cancer and tropic of capricorn.
Define Tropical Storms
An area of low pressure with winds moving in a spiral around the calm central point called the eye of the storm.
What way do tropical storms spin?
in the northern hemisphere, anti-clockwise
in the southern hemisphere, Clockwise
(Coriolis effect)
How are tropical storms catergorised
The saffir simpson scale
How will climate change affect distribution of tropical storms?
We may see tropical storms happen in more parts of the world as sea levels are rising.
How will climate change affect Frequency and Intensity of tropical storms
Oceans will stay at 27C for more parts of the year so number of tropical storms will increase. And higher temperature means they will be stronger causing more damage.
Primary and secondary effects of tropical storms.
Primary : Buildings destroyed
-rivers flood
-People drown due to storm surge
-Roads, railways and airports damaged.
Secondary:
-People left homeless
-Lack of clean water and poor sanitation
-Shortages of food as crops are damaged
Immediate and long-term responses to tropical storms
Immediate: Evacuate people before storm arrives
-Set up temporary shelters and temporary supplies
-Recover dead bodies to prevent spread of disease
Long-term:
-Repair homes or rehouse people
-Improve forecasting techniques to give people more warning
-Improve building regulations.
What is the case study for tropical storms?
Typhoon Haiyan
Facts about Typhoon Haiyan
Cat 5 typhoon
-Originated in the northwest pacific ocean
-8th November 2013
-Wind speeds up to 314km/h
Effects Typhoon Haiyan
6300 deaths
-30,000 fishing boats destroyed
-2 million homeless
-flooding
-400m of rain and 5m of storm surge
Responses of Typhoon Haiyan
-Red cross supplied over 1.1 million people with clean water to prevent poor sanitation
-Rebuilding of infrastructure
-Thousands of homes built away from flood risk
-£100 m aid sent.
How does monitoring/prediction reduce effects of TS:
Monitoring storms paths allows people more time to evacuate as they’ll be warned earlier
How does planning reduce effects of TS:
Emergency services can train and prepare for these scenarios, reducing casualties.
Governments can plan evacuation routes to allow more people to evacuate faster.
How does protection reduce effects of TS:
Buildings can be designed to withstand tropical storms, such as stilts to protect the building from floodwater.
What are some weather hazards that the UK expierience?
Rain, Thunderstorms, Heat waves, Droughts, Hailstorms , Snow and Ice, Wind
What is my case study for UK extreme weather?
‘The beast from the east’ 2018
Define Extreme weather
Extreme weather is a weather event which is significantly different from the average weather event. It doesn’t follow the usual weather pattern and is unseasonal.
Effects of the beast from the east
4 deaths reported
-Up to 19 inches of snow in parts of south-east Wales.
-Gusts of 60-70mph in parts of Northern England
-Temperatures as low as -12C
Secondary:
-British Airways cancelled hundreds of short-haul flights from heathrow, and London city airport also cancelled services.
-Scottish premiership postponed matches
-The weather cost the UK millions, insurance costs up to 10 million
-Schools closed
Responses of the beast from the east:
-Army called in to help people
-The met office issued red warnings for several areas
-Rail passengers warned to avoid travelling
-Public health England encouraged people to have enough food and medicine
Is there any evidence weather is becoming more extreme in the Uk?
Yes as the frequency of heatwaves has increases. They used to occur every 3 years now every 200 days.
Give a natural cause of global warming
Volcanic activity
Give two human causes of climate change
Enhanced greenhouse effect
Burning of fossil fuels
Secondary effects of Typhoon Haiyan
-6 million people lost income
-Landslides and blocked roads
-Water and food insecurity
-Power supplies lost for a month
-Disease outbreak.
