Physical Geo

What is the definition for distribution?

It is the spatial organisation of a hazard. Where it is happening.

What is the definition for Frequency?

It is the distribution of a hazard through time. (temporal distribution)

What is the definition of Magnitude?

It is the assessment of the size of the impact of a hazard event.

What is the Volcanic Explosivity Index?

It is a Logarithmic scale running from 0-8

What does the VEI measure?

the volume height and duration of an eruption.

What are the different volcanic hazards?

• Acid rain - sulphuric gases emitted by the volcano
• Pyroclastic flows - high sped avalanches of gas.
• Lava flows
• Volcanic gases - carbon monoxide, chlorine and sulphur dioxide
• Volcanic bombs - large pieces of material ejected over large distances
• Lahars - volcanic mudflows
• Volcanic ash clouds - has global and local effects e.g destruction of vegetation.

Factors that influence perceptions of natural hazards

Socio-economic status
Level of Education
Past experience
Family and marital status
Religion, cultural/ ethnic background

Definition of the perception of adaptation

Adjusting to living with hazard events

Definition of the perception of fatalism

The view that people cannot influence the outcome so nothing can be done to mitigate that

Definition of the perception of fear

People feel very vulnerable to an event that they arent able to face it and so they move to region that are perceived to be unaffected by the hazard.

What is Community Health Resilience?

It's the ability of a community to use its assets to strengthen public health and healthcare systems and to improve the community's physical, behavioural and social health to withstand, adapt to and recover form adversity.

What is Integrated risk management?

It's the process of considering social, economic and political factors involved in risk analysis.

What is the core made up of?

Dense rocks containing iron and nickel alloys and is divided into a solid inner core and a molten outer core with a temperature of 5000C.

What 2 processes mainly produce the heat?

Primordial heat - heat left over from the earth's formation
Radiogenic heat - heat produced by the radioactive decay of isotopes e.g Uranium 238

What makes up the mantle?

Molten and semi - molten rocks containing lighter elements such as silicon and oxygen

What makes up the crust?

Elements such as silicon, oxygen, aluminium and sodium which makes it lighter.

Characteristics of the continental crust?

30-70km thick
over 1.5 million years
has a light denstiy of 2.6cm³
Mainly made up of granite, silicon, aluminium and oxygen

Characteristics of the oceanic crust

6-10km thick
Less than 200 million years ago
Density of 3g/cm³ which is heavier than the continental crust
Mainly made up of basalt, silicon, magnesium and oxygen

What is the lithosphere?

The solid outer layer of the earth

What is the athenosphere?

It is semi - molten in which the plates float and move

What is the geological evidence for the tectonic plate theory?

South American and Western Africa coastline similarities

Late carboniferous glaciation ( 290 million years ago) deposits which are found in South America, Antarctica and India. Can't be explained by their current position.

What is the biological evidence for the plate tectonic theory?

Fossil brachiopods found in Indian limestone are comparable with similar fossils in Austrailia

Fossil remains of the reptile Mesosaurus are found in both South American and Southern Africa. It would have not been developed in both places nor would it have been able to migrate over the Atlantic

Fossilised plants which existed when coal was being formed have been located only in India and Antractica

What is the development of the plate tectonic theory?

Wegener's early theory could not explain how continental movement could have taken place so it gained little ground.

Wasn't until 1940's when people observed the mid - Atlantic ridge and other similar features in the Pacific Ocean that people began to take notice.

Mid - Atlantic ridge provided scientists with the evidence of sea floor spreading

What is the process of convection currents?

The hotspots around the core of the Earth generate thermal convection currents within the asthenosphere

These currents cause magma to rise towards to the crust and then spread before cooling and sinking.

Then this circulation of magma is the vehicle upon which the crustal plates move. The plates that make up the lithosphere can be thought of as 'floating' on the asthenosphere.

How does ocean ridges occur?

The plates move apart in oceanic ridges. The space between the plates is filled with basaltic lava upwelling from below to form a ridge.

How does a rift valley form?

The brittle crust fractures as sections of it move apart. Areas of crust drop down between parallel faults to form the valley.

How does deep sea trenches form?

Denser oceanic plate is forced underneath the lighter continental one. The downwarping of the oceanic plate forms a very deep part of the ocean known as a trench.

How are island arcs formed?

During subduction, the descending plate encounters hotter surroundings and this coupled with heat generated from friction begins to melt the plate. As this material is less dense than the surrounding asthenosphere, it begins to rise towards the surface as plutons of magma. Eventually these reach the surface and form comples, composite and explosive volcanoes. If the eruptions take place offshore, a line of volcanic island forms.

How do young fold mountains form?

The plate forming continental crust have a much lower density than the underlying layers so there is not much subduction when such plates meet. As such plates move towards each other, their edges and the sediments between them are forced downwards to form deep mountain roots.

How are ocean ridges formed in a constructive plate margin?

The plates move apart and the magma is forcing its way to the surface cooling and forming new crust.
As the plates move further apart from the ridge, this new crust is carried away from the ridge

How are subduction zones in destructive plate margins formed?

The plates go underneath other plates which melt into magma in a part of the subduction zone known as the Benioff zone. As it is less dense than the surrounding material , the molten magma begins to rise as plutons of magma which eventually reach the surface and form volcanoes.

How are rift valleys in constructive plate margins formed?

The brittle crust fractures as sections of it move apart. They are also thin crusts which drop down between parallel faults to form valleys. The magma forces its way to the surface to form volcanoes.

What is the focus of an earthquake?

The point at which the pressure release occurs within the crust

What is the epicentre of an earthquake?

The point immediately above the focus on the earth's surface, where the shaking begins.

What is the Richer scale?

It rates earthquakes based on the size of their seismic waves as measured by seismographs

For each unit increase, the energy released increases approx. by 30x

What is the moment magnitude scale (MMS)?

Rates earthquakes based on the total amount of energy they release. It uses more variables to calculate the energy released using seismic moment. Seismic moment combines the seismic energy with offset on the fault and rigidity of rock.

What is the Mercalli scale?

It's used to assess the strength of an earthquake by the damage caused on the earth's surface. The scale looks at areas surrounding the epicentre and looks at the effects on infranstructure, humans and nature. The scale is I to XII with XII being total destruction.

What are the 5 different seismic waves?

P wave
S wave
Surface wave
Love wave
Rayleigh wave

Characteristics of a P wave

Fastest wave
First to arrive from an earthquake
Moves in a longitudinal way
Able to travel through solid and liquid

Characteristics of S waves

Moves perpendicular
Slower than P waves (half the speed)
Higher amplitude than P waves
Can be S vertical and S horizontal
It moves the rock sideways at right angles to the direction of travel.
Unable to move in liquid due to the liquid being unable to spring back.

Characteristics of Surface waves

Slowest wave
Highest amplitude

Characteristics of Love waves

Moves side to side
Horizontal shaking damages the building foundations

Characteristics of Rayleigh waves

Moves vertically + horizontally in the direction the waves are travelling

Primary imapcts of the Icelandic volcano

Some airlines lost 130 million euros per day
7 million passengers stranded
7000 people had to leave their homes
1300 homes destroyed
Ash clouds closed European airspace

Secondary imapcts of the Icelandic volcano.

Many health problems from ash clouds e.g eye irritation.
Less tourism meant reduced money coming in
Travel agents in the UK lost £6 million each day
Estimated £400 million lost per day in Icelandic eruption
Increase local economy spending
Air ban reduced CO2 emissions.

Short term responses

Red Cross gave 60 volunteers to help people
1500 emergency beds
Info given every hour by the meterological team

Long term responses

Tech for airplane engines improved
More boost in local economies
New multiple data sets
New reporting protocols for severe eruption

How does a hurricane form?

Begins with an area of low pressure (clouds), resulting from surface heating. They can then enlarge into tropical depressions with rotating wind systems and these can continue to grow into even more intense and rapidly rotating systems.

How are tropical storms measured?

They are measured in categories form 1- 5 with 1 being low damage to 5 being catastrophic damage

What influences vulnerability in a tropical storm?

Intensity of the storm
Speed of movement 
Distance from the sea
Physical geography of the coastal area
Warnings and community response

Impacts of winds from a tropical storm

"Structural damage to buildings and roads, bridges. They can bring down powerlines and devastate agricultural areas."

Impacts of heavy rainfall from tropical storms

Severe flooding, landslides and mudslides.

Impacts of storm surges from tropical storms

Can cause large floods in low lying areas

How are tropical storms predicted?

• Flying into hurricanes with thermomenters and other equipment can provide data and statistics on the hurricane 
• Warning systems
• Round the clock surveillance and it's compared to computer models that are made.

How can tropical storms be prevented?

• Cooling the ocean wih icebergs to reduce evaporation
• Changing the radiation balance in the storm environment by blowing black soot into the storm

How can people be protected from tropical storms?

• Evacuate
• Drills for tropical storms
• Build sea walls and barriers
• Limiting development in high - risk areas
• Joint exercises between countries
• Some structures can be retrofitted (made to withstand winds)

How can people be prepared for a tropical storm to come?

• Emergency evacuation route
• Buy generator - in case of outage
• Emergency bag - 1 gallon of water, non - perishable food, batteries and torch

When did it occur?

24th August 2005 to 1st September 2005

Which states did Hurrican Katrina affect?

South Florida to Lousiana to Missisippi to Alabama

What were the impacts?

ECONOMIC
 Bush administration sought $105 billion for repairs and reconstruction in the New Orleans region

Katrina damaged/ destroyed 30 oil platforms and caused the closure of 9 refineries

ENVIRONMENTAL
Damage from Katrina forced the closure of 16 National Wildlife Refuges.

The storm surge caused substantial beach erosion which in some cases completely devastated coastal areas.

SOCIAL
By late January 2006, about 200,000 people were once again living in New Orleans which was less than half of the pre - storm pop.

Many people were left traumatised.

What were the responses?

Coast Guared rescued more than 33,500 out of 60,000 stranded in New Orleans.

Early in September 2005, Congress authorized a total of $62.3 billion in aid for victims.

FEMA also paid for the hotel costs of 12,000 individuals and families displaced by Katrina.

Law enforcement sent to deploy manpower in order to combat the widespread looting 

Kuwait made the biggest pledge: $500 million

India sent tarps, blankets and hygiene kits.

What can cause wildfires?

Hot temperatures and easily lit by a spark

Definition of a wildfire?

Uncontrolled fires that destroy forests, grassland and other areas of vegetation

Different types of wildfire?

Ground Fire - Where the ground burns. Slow with no flame and little smoke.

Surface Fire - Where leaf litter and low - lying vegetation burn.

Crown fire - Fire moves rapidly through the canopy.

What vegetation type allows a wildfire to happen?

Thick undergrowth or closely spaced trees which allow fire to travel easily

Some trees like eucalyptus contain a lot of oil and so it burns very easily

What fuel characteristics help a wildfire to spread?

Fine, dry material 

What climate and recent weather needs it to be in order for a wildfire to spread?

Strong winds - allows more oxygen to help the fire burn

Sufficient rainfall - so that vegetation can grow in order for it to act as a fuel for the fire

How does the fire need to behave in order for it to spread?

Can move along the ground surface slowly OR spreading rapidly which leads it to being more intense

Social effects of wildfires?

People may be killed or injured

Can cause health problems e.g breathing difficulties

Homes are destroyed so people become homeless

Political effects of wildfires?

Governments can face criticism when wildfires have severe impacts

May have to change their forest management practices to reduce risk of wildfire

Economic effects of wildfires?

May discourage tourists

Cost of fighting wildfires is huge

Insurance premiums increase dramatically after a wildfire

Environmental effects of wildifres?

Soils damaged.

Habitats destroyed

Smoke causes air pollution

Some plant seeds need fire to germinate ( good thing )

How can wildfires be prevented?

Managing the vegetation: Controlled burning to get rid of the litter

Managaing the built environment: Increasing the gap between vegetation and houses by incorporating more fire - resistant methods in construction

Warning systems: Lookout towers and even air patrols

How can people mitigate the effects of the wildfire on their home? x6

Children can be educated about the dangers
Shut off the gas to prevent explosions
Remove flammable furniture away from the windows

Install smoke detectors in all rooms
Keep the grass short so that it cannot burn
Have hoses connected outside to enable quick action to damp wildfires

How are wildfires measured?

Through a Macarthur Forest Fire Danger Index

Goes from low - moderate to catastrophic.

What do each of the levels mean in the Index?

Low - moderate: can be controlled
Severe: may be uncontrollable
Extreme: expected to be uncontrollable + unpredictable
Catastrophic  (Code Red) - Very very dangerous and should evacuate the area

How is the Forest Fire Danger Index calculated?

Temperature
Relative humidity
Wind Speed
Drought factor

What is the level of development like in the Philippines?

Life expectancy - 72 (2020)
GDP growth - 9.5% (2020)
26 per 1000 birth mortalities
LIC/NEE

What is the volcanic activity like in the Philippines? (3)

- Around 300 volcanoes
- 22 are active
- Volcanoes produced at a destructive plate boundary 

What has been the recent volcanic activity in the Philippines?

Mayon - erupted nearly 50 times in the last 400 years. Last erupted in 2014

Taal - erupted 33 times from the beginning and has killed 6000 people

Pinatubo - Remained dormant for almost 600 years until June 9th 1991 when it erupted

What are the seismic hazards like in the Philippines? (1)

Fairly common

- Between 2000 and 2013, there were 17 earthquakes with a magnitude of at least 5.6

Examples of seismic activity in the Philippines? (3)

1978 Mindanao - 7.9 earthquake triggered tsunamis which killed +8000 people

1990 Luzon - 7.8 earthquake killed 1600 people and caused widespread ground rupturing

2013 Buhol - 7.2 earthquake killed over 200 and injured 800

Tropical storm activity in the Philippines?

10 tropical storms cross the country year by year.

Brings the risk of severe flooding, landslides and lahars if combined with a volcanic eruption

Factors that increase the vulnerability of hazards in the Philippines? (3)

- Filipinos going to low - lying areas which can cause housing to be crammed

- Rapid urbanisation - due to tightly packed, flimsily constructed housing

- Deforestation - Steep slopes has led to rapid run off, flooding and landslides

Responses from hazards in the Philippines? (3)

- Training local volunteers in disaster management

- Preventing people from building in areas at high risk of disaster

- Increasing public awareness of hazards

What is the development like in Kobe? (3)

Life expectancy - 79 (1990) - 85 (2021)
GN1 - $19,730 (1990) - $43,740 (2021)
2nd school enrollment - 95% (1990) - 101% (2021)

Location of Kobe (3)

Population - 1.5m
7th largest city in Japan
Located on the southern side of the main island of Honshu

Background of Kobe (3)

7.2 magnitude
17th January 1995
At a destructive plate boundary

Effects of the earthquake in Kobe (4)

- Over 300 fires
- 350,000 homeless
- 6000 killed
- Water mains burst so it's slowed down the efforts of the firemen to stop the fire

How was it managed after the earthquake in Kobe? (3)

- Improved seismic resistance of existing buildings
- 70% of the port operations were restored within 1 year
- Improved the fire fighting capacity

Factors increasing vulnerability in Kobe (4)

- Lack of seriousness
- Earthquake happened in early morning (5:46am)
- Many buildings not retrofitted
- Infranstructure of the housing (heavy roof)

Factors decreasing vulnerability in Kobe (2)

- Earthquake proof freeway
- Earthquake observatories

When did Typhoon Haiyan become a Category 5 hurricane?

November 8th 4:50 am

Impacts of Typhoon Haiyan (5)

- Over 5,000 died
- 90% of all buildings were destroyed
- 6,000,000 displaced
- Outbreaks of disease due to lack of sanitation, food, water, shelter and medication
- Destroyed 33 million coconut trees

Responses to Typhoon Haiyan (4)

- UN fundraising reached $788 million
- Foreign nations donated $500 million
- Oxfam provided rice seed to farmers
- Save the Children helped build tent schools to educate children

What was the overall background of Black Saturday? (2)

- Happened from 7th February to 14th March 2009
- Affected 78 towns in Victoria

What are the increasing risks that led to Black Saturday? (2)

- Nearly 2 months of little or no rain and a very intense heatwave
- Winds reaching 100km/hr

What was the increasing vulnerability that led to Black Saturday? (2)

- Out of the 5 major fires burning, 4 of them spread 3x faster than anticipated

Impacts of the Black Saturday wildfires? (5)

- 173 people died with 414 people injured
- Over 2000 homes lost
- Melbourne's top 5 dams were contaminated with ash and other substances
- $1.2 billion had been spent in insurance claims with 84% for property and 16% for cars
- Total of 1.1m acres of land were burnt

Responses to the Black Saturday wildfires? (2)

- Creation of bushfire prevention strategies also resulted from the bushfires
- Massive international response as many countries sent out humanitarian and fire aid