P1 The Challenge Of Natural Hazards Flashcards
Definition of a natural hazard
A natural event that threatens people or has the potential to cause damage destruction or death
4 examples of tectonic hazards
Earthquake
Volcanic eruption
Landslides
Tsunami
2 types of geomorphological hazards
Floods,landslides
3 types of atmospheric hazards
Tropical storms
Droughts
Tornadoes
2 types of biological hazard
Pests
Diseases
Factors affecting hazard risk(and why)
- Population density, more people live in high risk areas as it is cheaper and they cant afford to move away
- Frequency and magnitude
- Wealth as hic’s are more prepared and able to cope than lic’s and nee-hics have strict construction laws in hazardous areas
- Climate change as rising temps can cause drought and tropical storms and wetter conditions can cause floods
- Human activities such as urbanisation and deforestation
What causes convection currents in the mantle
Hot core causes magma to rise in the mantle and sink when it cools,convection builds pressure and carries plates with it.
Explain the process of ridge push and what boundary it occurs at
- Magma rises as the plates move apart at constructive plate margins
- magma cools to form new plate material
- as it cools it becomes denser and slides down away from ridge
- this causes tectonic plates to move away from each other
Explain the process of slab pull and which plate boundary it occurs at
- Two plates converge towards each other at destructive plate margins
- Where the denser oceanic crust subducts under the continental crust
due to gravity pulling the rest of the plate with it
Global distribution of earthquakes and volcanic eruptions in relation to plate margins
-NOT random
-they occur on narrow bands along plate margins
-found on land AND sea
-earthquakes found at all 4: constructive,destructive,collision,conservative
-anomalies occur at hotspots where the crust is thinner
Physical processes that occur at constructive plate boundaries and an example
Example-Eurasian and North American plates
Hot molten magma rises between the plates
Tectonic plates move away from each other due to ridge push
Magma cools to form a new plate
This is where land rift valleys form
Physical processes that occur at destructive plate boundaries(+ example)
(Example:pacific and Philippine plates)
- Where tectonic plates converge, pressure builds between them
- the rock eventually fractures(causing earthquakes)
- when oceanic and continental plates collide,the denser oceanic plate is subducted,under the continental plate and into the mantle where it melts
- hot magma can rise through the lithosphere and erupt as lava through (cone)volcanoes
Give a named example of a tropical storm
Tropical storm Haiyan
What date did tropical storm haiyan happen?
8th November 2013
Where’re did tropical storm haiyan occur
The Philippines
describe the formation of a tropical storm
1) the suns incoming solar radiation to earth warms our oceans especially at the tropics
2) this warms the ocean to a criticle 27 degrees or above
3) this causes moist air to rise through the air in thermals, this gives low pressure at the cetre of the storm
4) this air cools as it rises causing cindensation to occur clouds to form and precipitation fall
5) some cool air sinks back diwn helping to create the eye
6) air rushes in from higher pressure areas outside of the storm to lower pressure areas at the centre ,creating winds.
7) the whole storm rotates because of the earthspin
What were the causes of tropical storm haiyan?
.water evaporates from the ocean
.most people live vulnerably along the coast and are unaware of the surge
.rising sea levels
What is a surface wind
Caused by air rushing from areas of high pressure to areas of low pressure
What is a pressure belt
These are caused by cool air sinking in some areas resulting in a belt of high pressure. Warm air rises in areas resulting in a belt of of low pressure.
Physical processes that occur at conservative plate boundaries(+example)
(Example:pacific and North American plates)
-sliding parallel past each other at different directions or at different speeds
-pressure builds at the margin of the tectonic plates as they are pulled along behind a plate subducted else where
-as friction is overcome rock fractures in an earthquake
Primary affects of earthquakes
- property,buildings and homes destroyed
- people killed and inured
- ports bridges roads and railways damaged
- pipes(water and gas) and electric cables broken(fire hazard)
Impacts of tropical storm haiyan
.primary deaths by drowning
.secondary deaths by disease and contaminated water
.5000 death
.20ft deep flood water third wave —> chronic illness, no medication
.135mph winds
.businesses destroyed
.desperation for food and water - supermarkets raided
.670,000 made homeless
.crop farms destroyed, loss of income
.26,000 injured
. Livelihood lost
.£3.6 billion in reconstruction
how does climate change affect the distribution of natural hazards
more places globally may experince tropical storms because oceans will become above 27 degrees in more areas
How many deaths were there from tropical storm haiyan
5000
What is the global distribution of storms
In the tropics. Between 5 and 30 degrees north and south of the equator
How fast were the winds of tropical storm haiyan
135mph
How much was the reconstruction cost of tropical storm haiyan
£3.6 billion
Secondary effects of earthquakes
-business reduced and money spent on repairs (economy slows)
-blocked transport infrastructure hinders emergency services(further casualties)
-fires from pipes and wires(further destroying buildings and killing people)
-burst water pipes lead to a lack of clean water and poor sanitation
A tropical storm in India is called?
cyclone
What were the responses of tropical storm haiyan
.floating mattresses to stop from drowning
.RAF delivered over 200 tonnes of aid after 10 days
.100 tonnes of rice
.doctors supplied
.fishing bodies from the sea
A tropical storm in the Pacific Ocean is called?
Typhoon
How does monitoring reduce the effects of tropical storms?
Can indicate where the tropical storm will go and what it will do, helps with predicting the storm
how does climate change affect the intensity of tropical storms
- causes sea temps to rise which means the storm gains more energy
- wind speeds could increase
- sea temps will stay above 27 deg for longer which means there could be a higher frequency
What direction do tropical storms turn in the northern hemisphere vs southern and why?
They turn anti-clockwise in the northern hemisphere and clockwise in the southern. This is due to the Coriolis effect.
how does climate change affect the
What is the date of the beast from the east
25th February 2018
How does planning reduce the effects of tropical storms?
Reduces death toll
What is the Coriolis effect
The spin of the earth induces an apparent motion to the right in the northern hemisphere and to the left in the southern hemisphere.
List the different weather hazards experienced by the UK
.drought
.heavy rain
.heat waves
.gales
.extreme cold weather
.thunderstorms
How many cm of snow were there from the beast from the east
50cm
How hot and why do temperatures need to be this high?
27 or above degrees, provides heat and moisture that causes the air to rise rapidly.
What is low wind sheer?
Winds that remain constant and do not vary in height, this allows the storm to rise to high levels without being torn apart
Why can’t tropical storms form at the equator?
The Coriolis effect is not strong enough for a storm to spin
Primary affects of Volcanic eruptions
-property and farmland destroyed
-people and livestock killed and injured (due to pyroclastic and lava flows and ash)
-collapsing buildings
-air travel holted due to airborne volcanic ash damaging engines
-water supplies contaminated
Secondary affects of a volcanic eruption
-economy slows
-emergency services struggle to arrive
-ice melts causing flooding
-flood water or rain mixes with ash causing lahars (mudflows)-further destroying property and killing people
-sulfur emissions leads to acid rain and contributes to enhanced greenhouse effect
Immediate responses to tectonic hazards
-issue warnings
-rescue teams search for survivors
-treatment given to those injured to prevent infection and spread of disease
-provide shelter food and drink
-recover bodies(avoid disease)
- extinguish fires
Long term responses to tectonic hazards
-repair and rebuild property and transport infrastructure
-improve building regulations
-restore utilities(water gas and electricity)
-resettle locals elsewhere
-install monitoring tech
what scale was the L’aquilla earthquake
6.3 on the richter scale
date of l’aquilla earthquake
6th april 2009
what time was l’aquilla earthquake
03:32 am
primary affects of l’aquilla earthquake
