Paper 1 - Tectonic Hazards

Question 1

What is a natural hazard?

Answer 1

Extreme weather events that pose potential risk to damage of property or loss of life.

Question 2

What are tectonic hazards?

Answer 2

Tectonic hazards ( earthquakes, tsunamis, volcanoes)
involve movement of the Earth’s tectonic plates in the Earth’s crust

Question 3

An example of a atmospheric hazard.

Answer 3

Hurricanes

Question 4

What are geomorphological hazards?

Answer 4

(Flooding)

Happens on the Earth’s surface

Question 5

What are biological hazards?

Answer 5

(Forest fires)

This involves living organisms.

Question 6

What are some factors that affect hazard risks?

Answer 6

• live in an at risk area e.g. on a plate boundary
• high population density
• wealth e.g. rich countries like Japan can prepare, protect and plan for tsunamis
• deforestation: removal of trees from slopes can cause soil erosion and in heavy rain, landslides can happen

Question 7

What is a tectonic plate?

Answer 7

A rigid segment of the Earth’s crust which can float across the heavier, semi-molten rock below.
Continental plates are heavier and less dense than oceanic plates.

Question 8

Plate margin

Answer 8

This is when two tectonic plates meet.

Question 9

The world distribution of volcanoes (3 marks)

Answer 9

Volcanoes occur in lines along plate margins for example the west coast of South America. There is anomaly to the trend as there’s a volcano in Hawaii which is 3200 km away from a plate boundary.

Question 10

The world distribution of earthquakes (3m)

Answer 10

Earthquakes tend to occur along plate margins for example the west coast of North America. However the anomaly to this trend is that there’s a few earthquakes that occur in Western China which is away from a plate margin.

Question 11

Give 2 differences between continental and oceanic crusts:

Answer 11

Continental crust is only 20-200 km whereas Oceanic plates are only 5-10 km. another difference is that oceanic plates are formed of basaltic rock whereas continental plates are mainly formed of granite rock.

Question 12

A constructive plate margin occurs when…..

Answer 12

Two plates (oceanic or continental) move apart.

1. Plates move apart
2. Hot magma rises as plates separate
3. Magma cools and hardens, forming new crust and a ridge
4. There is relatively gentle volcanic activity

Question 13

Destructive margin.

Answer 13

Example : Mt Chaiten 2008
Plates: Nazca/ South America
Landforms: Ocean trench, Fold mountain, volcano
Hazards: earthquakes and volcanoes
A destructive margin occurs where an oceanic plate and a continental plate converge (meet.)
At destructive margins, plates move together e.g Nazca Plate ( oceanic plate) and South American (continental plate.)The Denver,heavier oceanic plate subducts under the less dense continental plate by slab pull as gravity pulls the plate down at a 45’ angle.

Question 14

Explain why earthquakes occur at destructive margins.

Answer 14

Destructive margins are where the fence oceanic plate subducts under the less dense continental plate. This is called slab pul. As the Oceanic plate ( Nazca) subducts it causes friction with the continental plate ( South America) which triggers earthquakes as the plates jerk forward and exert pressure e.g. 9.5 richter Chile earthquake in 1960.

Question 15

Why do people live next to volcanoes / earthquake areas: geothermal energy

Answer 15

In volcanically active areas, geothermal energy is a major source of electrical power: steam is heated by hot magma in permeable rock, then boreholes are drilled into the rock to harness the super - heated steam to turn turbines at power stations.
~ It’s renewable energy.
It won’t run out and reduce greenhouse gases and the likely effects of climate change
~Hellsheidi power plant is the largest geothermal power station in Iceland and the second largest in the world.

Question 16

Why do people live next to volcanoes / earthquake areas: Farming

Answer 16

Lava and ash erupting from volcanoes kill livestock and crops and vegetation. After thousands of years weathering of this lava releases minerals and leaves behind EXTREMELY fertile soil. This land can be farmed in productively in these areas to provide a source of food and income e.g. MT Etna’s volcanic souls support 10% of the worlds population.

Question 17

Why do people live next to volcanoes / earthquake areas: Mining

Answer 17

Settlements developed where valuable minerals are found as jobs are created in the mine industry. Not only dormant and extinct volcanoes but also many active.
Kawah Ljen is an active volcano in East Java, Indonesia. It’s crater is one of the biggest sugar, makes matches, fertiliser and medicines.
~ miners can afford little protective clothing
~ hydrogen sulphide and sulphur dioxide burn their eyes.

Question 18

Why do people live next to volcanoes / earthquake areas: Tourism

Answer 18

They visit volcanoes for the spectacular and unique views and for the sense of danger. More than 100 million people visit volcanic sites every year. The revenue they generate benefits the locals and the countries they’re in. Mt Etna has 1.3 million visitors every year. This generates lots of jobs e.g. hotels, restaurants etc.

Question 19

L’Aquila, Italy background

Answer 19

Location: Abruzzo region of Italy
Plates: Africa’s and Eurasian Plate
Margin : destructive / collision boundary
Size: 6.3 in the Richter scale

Question 20

L’Aquila primary effects:

Answer 20

-308 ppl were killed.
-1,500 were injured
- 10,000 -15,000 buildings collapsed including:
~ many churches, medieval buildings and monuments with considerable cultural value
~ the Basilica of St Bernardino, the National Museum and Porta Napoli
~ San Salvatore Hospital was severely damaged and couldn’t cope with injured victims&raquo_space;> had to be evacuated
~ several buildings in L’Aquila Uni with fatalities in its student accommodation&raquo_space; built with poor cement

Overall the damage was reported US $11,474 million.

Question 21

Secondary effects of L’Aquila

Answer 21

• aftershocks triggered landslides and rockfalls causing damage to housing and transport
• a landslide and mudflow was caused by a burst main water supply pipeline near the town of Paganio
• the number of students at L’Aquila Uni had decreased
• The lack of housing meant housing increased
• City’s CBD has been cordoned off due to unsafe buildings.

Question 22

Short term responses of L’Aquila

Answer 22

~ hotels provided shelter for 10,000 people
~40,000 tents were given out
~ train carriages were used as shelters
~ Silvio Berlosconi offered some of his homes as temporary shapes
~ within an hour, the Italian Red Cross was searching 4 survivors. Helped by 7 dog units, 36 ambulances and a temporary hospital. Water, hot meals, tents and blankets were distributed.
~ British Red Cross raised $127,000 in support
~ mortgages, bills for Sky tv, gas and electric were suspended.
~ Italian post Office offered free mobile calls, raised donations and gave free delivery for products sold by small businesses
~ L’Aquila was declared a state of emergency which sped up international Aid to the area from the EU and the USA.
~ EU granted $552.9 million from its solidarity fund

Question 23

Long term responses of L’Aquila:

Answer 23

~ torch-lit procession took place with a catholic mass on the anniversary of the earthquake
~ Residents didn’t have to pay taxes in 2010.
~ students were given free public transport, discounts on educational equipments and were exempt from uni fees for 3 years.
~ homes took several years to rebuild and historic centres were expected to take 15 years to rebuild.

Question 24

Management of L’Aquila: prediction

Answer 24

They had seismometers recording earthquakes so when it happens they could respond quickly
The scientists had done a geological hazard map of Abruzzo so they knew L’Aquila was at risk.

Question 25

Management of L’Aquila: preparation

Answer 25

Emergency services had practiced drills for L’Aquila so they were within the hour with 7 sniffer dogs and heat seeking equipment to rescue people. They had heavy lifting equipment to rescue people and had done a drill “Drop, Cover,Roll”

Question 26

Management of L’Aquila: Protection

Answer 26

The buildings post 1980 had been built with earthquake proof designing bird cage steel which was a good management so only 308 died. But the uni student accommodation buildings fell due to the use of poor quality cement and Mafia involvement which shouldn’t have happened in a HIC.