IB Geography: GEOPHYSICAL HAZARDS
ALPS: Tourism
100 million tourists each year , 70% of tourists go for skiing, snowboarding and ice climbing, in summer people go for walks, mountain biking, paragliding and climbing, new villages have been built for tourists, lots of ski lifts, cable cars, holiday chalets and restaurants built
ALPS: Population?
12 million
MONTSERRAT: Death toll?
19 people killed
INDIAN OCEAN: Primary effects?
230, 000 people killed or still missing, whole towns and villages were destroyed, over 1.7 million lost their homes, infrastructure severely damaged, 5 - 6 million needed emergency food, water and medical supplies
ITALY: Primary effects?
290 deaths from collapsed buildings, hundreds injured, thousands of buildings damaged or destroyed, thousands made homeless, water pipe broken
MONTSERRAT: Size?
4 - 5 milion m3 of rock and gas was released
PAKISTAN: Long term response?
40, 000 relocated to new town of Balakot, government money has been given to those whose homes were destroyed so they can rebuild them, homes are being built more resistant, new health centres have been set up
ITALY: Size?
6.3 Richter scale
ITALY: When?
6th April 2009
PAKISTAN: Size?
7.6 Richter scale
PAKISTAN: Primary effects?
80, 000 deaths from collapsed buildings, hundreds of thousands injured, entire villages destroyed, 3 million homeless, water pipes and electricity were cut off
PAKISTAN: When?
8th October 2005
INDIAN OCEAN: Tsunami size?
9.1 on the Richter scale, 30m high waves
MONTSERRAT: Long term responses?
A risk map was created, and the south of the island is off limits whilst the volcano is active, UK has provided £41 million to develop the north of the island, new docks, homes, and airport, volcano observatory has been set up
Example of a destructive plate margin
Along the east coast of Japan
Example of a conservative plate margin
Along the west coast of the USA
What counts as a "major earthquake"?
An earthquake that ha a magnitude greater than 5
How does the Richter scale work?
An earthquake with a magnitude of 5 is 10 times one that has a magnitude of 4
Disaster
An event that causes great damage or harm
Example of oceanic and continental plates (fold mountains)
Andes in South America
ALPS: Adaptation - poor soils
Animals are grazed high up where the soil isn't very good for crops
Where do earthquakes occur?
At all three plate margins
Where are volcanoes found?
At constructive and destructive plate margins
Where do supervolcanoes form?
At destructive plate margins and over parts of the mantle that are really hot (hotspot)
Where are fold mountains found?
At destructive plate margins, or where there used to be a destructive plate margin - such are the west coast of the USA
Why do the plates move?
Because convection currents in the mantle caused by radioactive decay in the core moves the plates
INDIAN OCEAN: Long term responses?
Billions of pounds have been pledged to help rebuild the infrastructure, programmes have been set up to help people rebuild homes and get back to work, tsunami warning system has been put in place, disaster management and volunteers have been trained
INDIAN OCEAN: When?
Boxing Day 2004
ITALY: Immediate response?
Camps were set up for the homeless, ambulances, rescue dogs and the army were sent to rescue survivors, cranes and diggers removed rubble
ALPS: Where is it?
Central Europe, stretches across Austria, France, Germany, Italy, Liechtenstein, Slovenia and Switzerland
Order of the layers on the Earth (starting from the outside)
Crust, mantle, outer core, inner core
ITALY: Cause?
Destructive plate margin
PAKISTAN: Cause?
Destructive plate margin
INDIAN OCEAN: Cause?
Destructive plate margin, the plate that was moving down into the mantle cracked and moved very quickly
What do humans use fold mountains for?
Farming, hydroelectric power, forestry, tourism, mining
ITALY: Secondary effects?
Fires caused more damage, broken water pipe in Paganica caused a landslide, aftershocks hindered rescue services
MONTSERRAT: Secondary effects?
Fires destroyed many buildings including local government offices, police headquarters and the central petrol station. Tourists stayed away and businesses were destroyed, disrupting the economy, population decline - 8000 of the 12000 inhabitants have left since 1995, improved soil fertility
Characteristics of a supervolcano
Flat, cover a large area, have a caldera
Mining on fold mountains
Fold mountains are a major source of metal ores, but the steep slopes make it difficult to mine them, so zig zag roads have been built
ALPS: Formation?
Formed about 30 million years ago, by the collision between African and European plates
ALPS: Adaptation - steep relief
Goats are farmed because they are well adapted to live high up, also trees are planted as a natural defense against avalanches
Forestry on fold mountains
Good environment to grow some types of trees like conifers, grown for fuel, building materials and paper and furniture
Primordial heat
Heat lost by the Earth as it cools
PAKISTAN: Immediate response?
Help didn't reach many areas for days or even weeks, people had to be rescued by hand without equipment or emergency services, tents, blankets and medical supplies were distributed within a month, but not to all areas, helicopters and rescue dogs were brought in from other countries
Farming on fold mountains
Higher mountain slopes aren't good for growing crops, so animals are allowed to graze there instead, lower mountain slopes are used for crops, and are sometimes terraced if they are too steep
Example of two continental plates (fold mountains)
Himalayas in Asia
Example of a hotspot volcano
In Hawaii volcanoes have formed over ares of very hot magma
INDIAN OCEAN: Where did it affect?
Indonesia, Thailand, India, Sri Lanky
MONTSERRAT: Cause?
It is above a destructive plate margin, where the Atlanic plate is being forced under the Caribbean plate, magma rose up through the cracks forming and underground pool of magma. The rock above the pool collapsed causing an eruption
What will happen if a supervolcano erupts?
It will throw out thousands of cubic kilometres of rock, ash and lava (a normal volcano will only produce a couple of cubic kilometres), everything within ten miles will be dead, because a huge super heated cloud of ash and gas will flow at high speed, ash will block out sunlight over whole continents, triggering a mini ice age
MONTSERRAT: When?
June 25th, 1997 (small eruptions started in July 1995)
PAKISTAN: Secondary effects?
Landslides buried buildings and people, blocked roads and cut off water, electricity and phone lines, diarrhea spread due to little clean water, freezing winter conditions caused more casualties and made rescuing more difficult
MONTSERRAT: Primary effects?
Large areas covered with volcanic material, capital city Plymouth covered in 12m of mud and ash, over 20 villages and two thirds of homes destroyed by pryroclastic flows, 19 people died and 7 injured
ITALY: Preparation?
Laws on construction standards, but some modern buildings weren't built to withstand earthquakes, Civil Protection Department that trains people to help with rescue operations
Characteristics of fold mountains
Lots of very high mountains, very rocky and with steep slopes, often snow and glaciers in the highest points and lakes in the valleys
Cinder volcano
Made of fragments of solid material, forming a steep conical hill, not very high
Composite volcano
Made up of ash and lava that has erupted and cooled and hardened into layers, the lava is usually thicc and flows slowly and hardens quickly forming a steep sided volcano
Dome volcano
Made up of only lava, lava is thick and flows slowly and hardens fast, forming a steep sided volcano
Shield volcano
Made up of only lava, which is runny, flows quickly and spreads over a large area, forming a low, flat volcano
How do supervolcanoes form over hotspots?
Magma rises up through the crust to form a large magma basin below the surface, the pressure of the magma causes a bulge on the surface, several kilometers wide, the bulge eventually cracks creating vents for lava to escape through, the lava erupts out of the vents causing earthquakes, and sending up loads of ash
Example of a shield volcano
Mauna Loa, Hawaiian islands
How does the Mercalli scale work?
Measures the effects of an earthquake, by asking eye witnesses about what happened
How can scientists try to predict when a volcano will erupt?
Monitor volcano for things such as tiny earthquakes, escaping gas and changes in the shape of the volcano by using satellite images
ALPS: Tallest peak?
Mont Blanc at 4810m on the France-Italy border
Example of a composite volcano
Mount Fuji, Japan
Example of a dome volcano
Mount Pelee in the Caribbean
ALPS: HEP
Narrow valleys are dammed to generate HEP e.g. Berne, Switzerland. Switzerland gets 60% of its electricity from HEP, used locally but also exported
PAKISTAN: Preparation?
No local disaster planning was in place, buildings were not designed to withstand earthquakes, poor communications and roads
MONTSERRAT: Immediate response?
People were evacuated from the south to safe areas in the north, shelters were built, UK provided £17 million of emergency aid, rescue services were sent to find survivors
ITALY: Long term response?
Prime Minister promised to build a new town to replace L'Aquila, investigation as to why the buildings collapsed
ALPS: Adaptation - limited communication
Roads have been built over passes (low point between the mountains) but it takes a while to cross, and snow can block them, so tunnels have been built such as the Lotschberg Base Tunnel in Switzerland
ALPS: Mining
Salt, iron ore, gold, silver and copper were mined, but mining has declined due to cheaper foreign sources
ALPS: Forestry
Scots Pine is planted all over as it is very resilient to the munching goats, they are also logged and sold to make furniture
What is the mantle made of?
Semi molten rock that moves very slowly
What is the core made of?
Solid iron and nickel
Tourism on fold mountains
Spectacular scenery, in winter you can do skiing, snowboarding and ice climbing, in summer you can go on walks. To make transport easier, tunnels have been built through the mountains to make transport easier, improving communications
How do earthquakes occur at constructive plate margins?
Tension builds along cracks within plates as they move away from each other
How do earthquakes occur at destructive plate margins?
Tension builds up when one plate gets stuck when moving down past the other
How do earthquakes occur at conservative plate margins?
Tension builds up when plates that are grindin past each other get stuck
MONTSERRAT: Where?
The Soufreire Hills in Montserrat,a small island in the Caribbean Sea
MONTSERRAT: What?
The Soufriere Hills volcano
What happens if a continental and an oceanic plate meet at a destructive plate margin?
The heavier more dense oceanic plate sinks underneath the continental plate and forced down into the mantle and melted. This can cause volcanoes and very deep ocean trenches
How is a volcano formed at a constructive plate margin?
The magma rises up through the the gap between the tow plates moving apart
Example of a constructive plate margin
The mid Atlantic ridge
Hazard event
The occurrence of a hazard, the effects of which change demographic, economic and/or environmental conditions
How is a volcano formed at a destructive plate margin?
The oceanic plate goes underneath the continental plate, is goes into the mantle and is melted, creating a pool of magma, which rises through the the cracks in the crust called vents, and erupts on the surface
What happens if two continental plates meet at a destructive plate margin?
The plates smash together, but no crust is destroyed
Hydroelectric power on fold mountains
There are steep sided mountains and high lakes to store water, making it great for HEP
What happens after a supervolcano has erupted?
There is no longer anything in the magma basin, so the rock collapses, causing a caldera
Continental crust
Thicker and less dense
Oceanic crust
Thinner and more dense, older, sometimes up to 200 million years old
INDIAN OCEAN: Secondary effects?
Tourism industry suffered, fishermen couldn't fish, salt from sea water meant that plants can't grow in many areas, mangroves, coral reefs, forests and sand dunes were also destroyed
ALPS: Farming
Used to farm goats high up, which provide milk, cheese and meat, sunnier slopes have been terraced to plant vineyards such as in Lavaux in Switzerland
Example of a cinder volcano
Volcano Du Fuego, Guatemala
How are fold mountains formed?
When plates collide at destructive margins, the sedimentary rocks that have built up between them are folded and forced upwards to form mountains
Constructive plate margin
When two plates are moving away from each other, and magma rises up from the mantle to fill the gap, and cools creating a new crust
Conservative plate margin
When two plates are moving sideways past each other, or are moving in the same direction but at different speeds, crust isn't created or destroyed
Destructive plate margin
When two plates are moving towards each other
INDIAN OCEAN: Short term responses?
Within days hundreds of millions of pounds had been pledged by foreign governments, charities, etc to give water food, shelter and medical attention, ships and planes were sent and teams of specialists to rescue people from other countries
Example of a supervolcano
Yellowstone National Park or Lake Toba in Indonesia