With reference to two seismic events that you have studied from contrasting areas of the world, compare the ways in which earthquakes and their impacts have been managed. (10)

With reference to two seismic events that you have studied from contrasting areas of the world, compare the ways in which earthquakes and their impacts have been managed. (10)

In 2010, an earthquake of 7.0 magnitude on the Richter Scale caused massive destruction on the Caribbean island of Haiti. This was caused by the North American plate sliding past the Caribbean plate, but travelling at different speeds, albeit going in the same direction.

A similar scaled earthquake occurred in 2003 in California, with a magnitude of 6.5 on the Richter Scale. This was along along the conservative plate margins that run parallel to the San Andreas Fault. 

Both events were similarly scaled, however, it was their impacts which had varied at a very large scale, and how they were managed which made a difference. 

In Haiti, more than 300,000 people were killed and a further 1 million were made homeless, as several buildings, including the President's Palace and 60% of the government buildings were either destroyed or badly damaged. With no strong government, nor a running police force, crime had gone up immensely, on top of the underlying problems such as diseases spreading, as more than 50 hospitals were destroyed and education neglected with more than 1500 schools collapsed. 

The effects in California, contrastingly, were far less destructive, as there was relevant planning beforehand, as they are an area prone to earthquakes. Buildings were rebuilt with reinforced concrete in order to withstand earthquake energy. So, in 2003, the death toll was one person- due to the pre-planning by scientists and government officials passing a law that buildings have to have certain features (reinforced steel and concrete, only be at a certain height, have support of ball bearings, and an earthquake panic room in schools and hospitals).

Haiti,, ultimately received millions of pounds in foreign aid, and due to its level of development (LIC), and how the media had portrayed the situation, had heightened the amount of aid it had received. Most of the recognition of Haiti came from celebrities raising awareness to the impacts, even recording a chart topping song to raise awareness for the people of Haiti,

California, however did not receive any aid due to its planning beforehand, and its level of development, being an HIC, and shows that due to its level of preparedness, as they are prone to seismic activity and so there was much better management about the consequences of earthquakes.

With reference to 2 volcanic events you have studied, from contrasting areas of the world. Compare the ways in which their impacts have been managed (10)

With reference to 2 volcanic events you have studied, from contrasting areas of the world. Compare the ways in which their impacts have been managed (10)

In the past few decades, there have been several volcanic events that have occurred and the way their impacts have been managed have differed around the globe.

The eruption of Mt. Nyiragongo, Congo, January 2002 had killed 147 people and over 350,000 people had fled the area. The local authorities initial response was to initiate a 'red alert'. This enabled Goma and the surrounding area to be evacuated and the prompt response was one of the key factors in keeping the death toll relatively low. 

The eruption of Mt. Etna in Sicily also took place in the same year as the eruption of Mt. Nyiragongo but the death toll was less than half of Congo- at 77 confirmed deaths. Although government intervention is rare, a significant early intervention did occur by the authorities. Initial attempts at halting lava flows via hastily constructed earth barriers on the approach to the town, proved to be unsuccessful. 

Two days after the eruption in Goma, humanitarian aid was provided by the United Nations. Emergency rations were initially provided, this included high energy foods like chocolates and biscuits and it was only later that more substantial food were given to local people (maize, beans, cooking oil) as communication and transport accessibility to affected areas had improved. 

However, unlike Nyiragongo, Etna has had a long history of people living nearby the mountains and consequently have gained much experience of managing the impacts. As a result, no humanitarian aid was provided by overseas agencies. 

To disrupt and redirect the lava flow, explosives were detonated near the source of the lava to break up the very efficient 'lava tube system' which was guiding the lava for some 7km down slope. None of Etna's slopes were damaged however there was some damage to the agriculture and tourism in nearby area. The Italian government had pledged immediate financial assistance of £5.6 million and tax-breaks for three months for all of the villagers. 

In Congo, however, the financial situation was not quite the same, The UN had estimated the cost of providing food, clean water, shelter, medical attention and blankets to be about $15 million.

An even higher cost was incurred to Goma's infrastructure, rebuilding homes and livelihoods. The lava flows had destroyed many businesses resulting in massive increases in unemployment in the area. So, though they had received aid from overseas, they consequently had a much harder time getting back on their feet than Sicily- and this, to a great extent, is largely due to their lack of management and awareness during the time of the eruption. 

Describe and explain the characteristics of earthquakes (8)

Describe and explain the characteristics of earthquakes (8)

Earthquakes occur when a build-up of pressure within the Earth's crust is suddenly released and the ground starts shaking violently. The point within the crust, at the lithosphere, where pressure is released is called the focus. The focus in an earthquake, can be found at a range of depths, at a shallow focus, which is 0-70km deep, at an intermediate focus which is 70-300km deep and at a deep focus, at 300-700km deep. The focus is not necessarily at a single point- it could be along a fault line. It is near the focus, where waves are stronger and cause more damage, as that is where there is the highest level of energy. 

The place at the Earth's surface immediately above the focus is called the epicentre, it is where the earthquake is felt first. It receives the highest amount of energy and so is the most potentially hazardous location.

From the focus, there are seismic waves which travel out. There are three main types: Primary (P) waves, which are the fastest, are those that can travel through solids and liquids, they can travel through the mantle and the core. The waves push and pull the earth in the same direction as the wave is travelling. Secondary (S) waves can also travel through solids, but not through liquids- so they can travel through the mantle but not the core, so they cannot be measured at a point opposite the focus or epicentre. They move the earth at 90 degrees (at a right angle) to the direction of travel. They do a lot more damage than P waves due to their shearing effect. Surface waves travel the slowest, but cause the most damage. They are further split into surface love (L) waves- which are the slowest waves and cause most damage or Rayleigh waves, which radiate from the epicentre in low-frequency rolling motions.

Comments: 8/8 well done. Some sort of conclusion would help, if time permits. 

Describe and explain the characteristic features of various types of volcanoes (8)

Describe and explain the characteristic features of various types of volcanoes (8) 

There are a variety of diverse volcano types which vary in characteristics. 

Composite volcanoes, sometimes called Strato cones, occur on destructive margins and are the classic pyramid-shaped volcanoes consisting of layers of ash from initial explosive phases of eruptions and subsequent layers of lava from the main eruption phases. The eruptions from these volcanoes may be from pyroclastic flows rather than a flow of lava. A pyroclastic flow is a super heated mixture of hot steam, ash, rock and dust. It can travel down the side of a volcano at very high speeds with temperatures over 400 degrees Celsius. The eruptions are fairly explosive due to the thick, highly viscous lava. An example of this is Mt. Pinatubo in the Philippines.

Secondly, there are shield volcanoes, which often occur at constructive plate boundaries, formed mostly from basaltic rock, which thus produce fast flowing (less viscous) lava that can flow for many miles, They are low lying, with gently sloping sides, with eruptions that are typically non-explosive, frequent, but relatively gentle. These eruptions can destroy property, however, due to how predictable they are, injury and death to humans is rare. They can sometimes be found at volcanic hot spots, including Mt, Kilauea in Hawaii.

A third type of volcano is a dome volcano (acid volcano), which are steep-sided, convex cones, consisting of viscous lava- which is mostly rhyolitc- very thick and sticky, which does not usually flow far, before t cools and hardens. An example of this is Puy de Done in the Auvergne region of France, which last erupted over a million years ago.

Another type of volcano is caldera, which forms when the build-up of gases beneath a blocked volcano vent becomes extreme and a huge explosion removes the summit of the cone, leaving an opening several kilometres in diameter. Calderas volcanoes, such as Krakatoa in Indonesia have large, deep openings, filled with water. Calderas have steep slopes due to rhyolitic lava- which is erupted from them. They frequently emit smoke and ash, but erupt irregularly and violently, due to how viscous they are.

Comments from sir: If you can revise all of this within the time allocated, then you have nailed it. Well done. 8/8
Characteristic features are common to all and must be mentioned: shape, ferocity, viscosity etc.