Geography

!6 reasons as to why to live in tectonic areas/close to volcanoes

1. Some settlements have grown into enormous cities and would be hard to move anywhere else 2. Some places are well prepared for hazards so people feel safe 3. A good job and way of life may keep you in a danger zone 4. Sulphur can be mined, Ljen volcano has a crater lake, which is the site of a sulphur mining operation, because of the high sulphur levels on the lake floor 5. Volcanic soils are fertile as the weathering of volcanic rock releases potassium into the soil, which is essential for plant growth e.g. Naples, Italy has olives, vines, nuts and fruit (mainly oranges and lemons) growing area to Mount Vesuvius. 6. Tourism is a popular activity in these areas. Mount Etna, attracts thousands of tourists, who travel in cable cars and 4 wheel drives to the crater, providing a range of jobs for local people. The Blue Lagoon in Iceland is heated by geothermal heat and 1.2 million people visited the Lagoon in 2010 7. Magma contains a large amount of minerals, such as, copper, gold, silver, lead and zinc. After an eruption this magma cools and these minerals can be mined. E.g. Yanacocha gold mine in Peru 8. Large settlements in seismic zones offer job opportunities, such as San Francisco in the USA. San Francisco is in the Bay area, which has a GDP of $535 billion, & ranks 19th in the world when compared to national economies. 9. People in Mount Merapi, Indonesia, worship ancient spirits believing they will warn them of an eruption, on a full moon they throw items into the volcano crater to calm the volcano's spirits. 10. The World's best coffee is grown on volcanic soil in Columbia. 11. People believe the chances of the volcano erupting are very slim 12. In Iceland volcanoes provide cheap geothermal power, 28 % of all its energy. This is even used to heat pavements in winter in Reykjavik. 13. Poor people, especially in LICs cannot afford to live away from volcanoes as they provide jobs and their families and friends live there. 14. Basalt is found in volcanic areas and can be used in construction and to build roads. 15. Engineering can make people feel safe in these areas in richer parts of the world. Buildings can be made to be earthquake proof like the Bird's Nest stadium in Beijing. 16. Many volcanic and earthquake events are infrequent- so people don't think they will get caught up in a disaster.

A hazard

A natural event (for example an earthquake, a volcanic eruption, etc) that threatens people or has the potential to cause damage, destruction and death.

Tectonic hazard

A natural hazard caused by movement of tectonic plates (including volcanoes and earthquakes).

Tectonic plate

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

Protection

Actions taken before a hazard strikes to reduce its impact, such as educating people or improving building design.

Planning

Actions taken to enable communities to respond to, and recover from, natural disasters, through measures such as emergency evacuation plans, information management, communications and warning systems.

Tropical storms

An area of low pressure with winds moving in a spiral around the calm central point called the eye of the storm. Winds are powerful and rainfall is heavy. They can last for days to weeks within the Tropical regions of our planet. Hurricanes occur when these tropical storms develop wind speeds of over 74 mph (miles per hour). They are known by many names, including hurricanes (North America), cyclones (India) and typhoons (Japan and East Asia).

Animal Behaviour (Earthquakes)

Animal behavior has been suggested as a method, as many observations have shown that animals react to an earthquake before the event and well before human beings. Tilt meters can show ground deformation, leading to an earthquake. These have been replaced in many cases by more modern and wider ranging satellite imagery.

Biological Hazards

Any biological substance that poses a threat to the health of people

Monitoring gas emissions (volcanoes)

As Magma rises into magma chambers gases escape. One of the main gases is Sulphur Dioxide, and if its quantity in escaping volcanic gas increases this can signal the start of a major eruptive sequence. In the Mount Pinatubo Volcanic event the amount of Sulphur Dioxide increased by 10 times in 2 weeks.

Conservative margins

At conservative margins mountains are not made, volcanic eruptions do not happen and crust is not destroyed. Instead, 2 plates either slide past each other in opposite directions, or 2 plates slide past each other at different speeds. As they move past each other stress energy builds as the plates snag and grind on one another. When this stress energy is eventually released it sends shock waves through the earth's crust. We know these shock waves as earthquakes.

Destructive or Convergent Margins

At these margins 2 plates move or converge together and the destruction of some of the Earth's crust results. An oceanic plate (denser) is pushed towards a continental plate (less dense) by convection currents deep within the Earth's interior. The oceanic plate is subducted (pushed under) the continental plate at what is called a subduction zone, creating a deep ocean trench. It is the Oceanic crust which sinks down into the mantle because it is denser (heavier). As it descends friction, increasing pressure and heat from the mantle melt the plate. Some of this molten material can work its way up through the continental crust through fissures and cracks in the crust to collect in magma chambers. This is often some distance from the margin where magma can eventually re-emerge at the surface to create a range of mountains. The movement of the plates grinding past one another can create earthquakes, when one plate eventually slips past the other releasing seismic energy.

Constructive or Divergent Margins

At this type of plate margin two plates are moving apart (diverge) from each other in opposite directions. Convection currents moving in opposite directions (caused by the intense heat of the Earth's interior) in the mantle move two plates apart. As these plates move apart this leaves cracks and fissures (lines of weakness), that allows magma from the mantle to escape from the highly pressurised interior of the planet. This magma fills the gap and eventually erupts onto the surface and cools as new land. This can create huge ridges of undersea mountains and volcanoes, and where these mountains poke above the level of the sea, islands are created. Both earthquakes and volcanoes can result at these margins, the earthquakes caused by the movement of magma through the crust.

Prediction

Attempts to forecast when and where a natural hazard will strike, based on current knowledge. This can be done, to some extent for volcanic eruptions and tropical storms, but less reliably for earthquakes.

The UK is becoming more extreme. Give one example as to how.

Beast from the East. In February 2018 the UK experienced a massive snowstorm called Beast from the East.

Water based hazards

Created by rivers, sea or oceans

Terrestrial/Geological hazards

Created by the movement of the Earth's tectonic plates or surface rock and soils

Atmospheric hazards

Created in the atmosphere, by the movement of air and water.

Seismometers (Earthquakes)

For earthquakes the equipment above is used plus other equipment and measures, these include; Using foreshocks by monitoring seismic waves- we often get small earthquakes before "the big one" that can give warnings. The Japan Tsunami (mag 9.0) was preceded by a massive magnitude 7.2 earthquake.

Technology

HICs can afford the technology to help them predict events, the USA has the United States Geological Survey to collect earthquake data from seismometers for example. They also have the technology to help buildings survive various natural hazards

Haiti Earthquake, Caribbean (LIC)

Haiti is the poorest country in the Western Hemisphere, its GDP is only $1,200 per person, 207th in the world, and its HDI is incredibly low at 0.404, 145th in the world and 80 % of its 9.7 Million people live below the poverty line. Port Au Prince, the capital, is on a fault line running off the Puerto Rico Trench, where the North American Plate is sliding under the Caribbean plate. There were many aftershocks after the main event. The earthquake occurred on January 12th 2010, the epicentre was centred just 10 miles southwest of the capital city, Port au Prince and the quake was shallow—only about 10-15 kilometres below the land's surface. The event measured 7.0 on the Richter Magnitude scale.

Preparations

If a place is well prepared regardless of its level of development this can limit the impact of a hazardous event. In India, despite its low level of economic development, rounded wooden houses have been designed to be earthquake proof, thus limiting the impact of these hazards.

The Kobe Earthquake - an earthquake in an HIC (High Income Country)

Kobe is located in the south east of Japan, near a destructive plate margin. It is a mega city and has one of the largest container ports in the World. Although further from a plate margin than most of the cities in Japan, Kobe is still found on a fault line. The earthquake that hit Kobe during the winter of 1995 measured 6.9 on the Richter scale. At this plate margin, the Pacific plate is being pushed under the Eurasian plate, stresses build up and when they are released the Earth shakes. This is known as an earthquake happening along a subduction zone. The focus was only 16 km below the crust and this happened on the 17th Jan 1995 at 5.46 am. 10 million people live in this area.

Laser beams (earthquakes)

Laser beams can be used to detect plate movement by directing the beam across the fault line.

Agencies

Many HICs have agencies that can act quickly to help people after a disaster, such as a well-equipped army or fire service and experts to coordinate a response in both the short and long term.

Planning laws

Many HICs have laws that prevent building in hazardous locations, along a low coastline at risk from storm surges in a hurricane.

Short term responses (Haiti Earthquake)

Many countries responded to appeals for aid, pledging funds and dispatching rescue and medical teams, engineers and support personnel. Communication systems, air, land, and sea transport facilities, hospitals, and electrical networks had been damaged by the earthquake, which slowed rescue and aid efforts. There was much confusion over who was in charge, air traffic congestion, and problems with prioritisation of flights further complicated early relief work. Port-au-Prince's morgues were quickly overwhelmed with many tens of thousands of bodies having to be buried in mass graves. As rescues tailed off, supplies, medical care and sanitation became priorities. Delays in aid distribution led to angry appeals from aid workers and survivors, and looting and sporadic violence were observed. Medicines San Frontiers, a charity, tried to help casualties whilst the USA took charge of trying to coordinate Aid distribution

Solutions (Kobe Earthquake)

Preparation - A lot of the buildings in Kobe and Japan made after the 1960s are earthquake proof (necessary by law) with counterweights on the roofs and cross steel frames. Many of the damaged buildings in Kobe were built before this period and were made of wood, which caught fire. People are educated on earthquake preparation in Japan. Prediction - Japan has the world's most comprehensive prediction programme with thousands of seismometers and monitoring stations in Japan designed to give warning. Kobe hadn't had an earthquake in 400years and had less prediction equipment than other areas of Japan. Aid - The Japanese rejected international offers of aid and dealt with the earthquake itself. All of the homeless people were dealt with reasonably quickly and the city recovered thanks to government money.

Monitoring

Recording physical changes, such as earthquake tremors around a volcano or tracking a tropical storm by satellite, to help forecast when and where a natural hazard might strike.

Education

Regardless of level of development people can be educated to survive natural hazards. Education about the risks of contaminated flood water or Earthquake drills (like the ones Japan has on the 1st September to commemorate the 1923 Tokyo Earthquake) can save many lives.

Satellite Images and Remote Sensing (volcanoes)

Remote sensing is the use of satellites to detect things about the Earth's surface. This is useful for monitoring any changes in volcanoes at the surface. Using satellites we can monitor the heat or thermal activity of the volcano to check for up welling magma, we can check for escaping Sulphur dioxide using gas sensing and we can look to see if the ground is deforming by checking before and after images of the ground.

Seismic waves (volcanoes)

Scientists can use seismic or earthquake waves to show if a volcano is getting ready to erupt. Many volcanoes experience an increasing intensity in frequency and size of earthquakes as they prepare to erupt. We can monitor these using seismometers which produce seismographs. This technique was used in Nevado Del Ruiz in 1985 and for Mount Pinatubo in 1991.

Predict

Some natural hazards are easier to predict than others, hurricanes can be identified by satellites and then tracked. This allows governments to evacuate if needed.

Factors affecting hazard risk

Some places are more vulnerable to natural hazards and some places have a lower capacity to cope as they have weaker infrastructure, poor government organisations and agencies (such as the army, or police) or low quality equipment.

how tropical storms form

Step 1- the sun sends incoming solar radiation to Earth which warms our oceans. Step 2- this warms the ocean to a critical 27°C. Step 3- this causes warm moist air to rise through the air in terminals. This gives low pressure at the centre of the storm. Step 4- This air cools as it rises, at 1°C per 100m, this causes condensation to occur, clouds to form and rain to occur. Step 5- Some cooled air sinks back down helping to create the eye. Step 6- Air rushes in from higher pressure areas outside of the storm to lower pressure areas at the centre of the storm creating winds. Step 7- The whole storm rotates because of the Earth's spin.

Management strategies

Techniques of controlling, responding to, or dealing with an event.

Management

The 3Ps (Predict, Prepare and Prevent)

Natural Hazards - Global Atmospheric Circulation

The Earth's atmosphere is in constant motion and is driven by the energy we receive from the sun. The air moving around the globe does so because we get more energy in tropical areas and less at the poles. Air movements or winds help to balance this out. Most insolation arrives between the 2 Tropics. This causes air to rise from the surface UP through the atmosphere in thermals at the Inter Tropical Convergence Zone (ITCZ). This creates huge cumulonimbus clouds as the air cools, Tropical storms with low pressure occur here. As the air heads North and South it cools and then sinks back down to the surface at approximately 30°N & S giving HIGH pressure. This goes back to the Equator as the TRADE winds or tropical easterlies. Two further cells exist further North and South. These cells are called the Hadley, Ferrel and Polar cells, giving 6 in total (3 in either hemisphere).

Tectonic plates (key info)

The Tectonic Plates vary in size and the Earth's surface can be likened to that of a boiled egg which has been cracked. The major plates include the Pacific, Eurasian, African, Antarctic, North American and South American, and the Indo-Australian. There are other smaller plates however, such as the Philippines and Cocos plates. The tectonic plates join at zones called plate margins, where most of the world's volcanic and earthquake activity occurs. Remember that this is a theory proposed by Alfred Wegener as continental drift in 1912, and is now supported by lots of evidence since.

Time

The amount of time since the last hazardous event can influence the impact, if a long time goes by people can be unprepared. Also, if the hazard occurs when lots of people are asleep they can also be unprepared. The Christchurch Earthquake of 2011 happened during the day when lots of people were at work, this contributed to the death toll as many got trapped in collapsed office buildings.

Protection (earthquakes)

The best way to protect people from tectonic hazards is to look at the way we construct buildings and roads. Buildings can be designed to withstand the shaking of the earth and to limit the loss of life and damage caused. The Transamerica pyramid has a shape that can withstand seismic waves and withstood the 1989 Loma Prieta earthquake which struck San Francisco. Other strategies include rolling weights on the roofs of buildings, shatterproof glass to prevent scattering glass during a quake, emergency shutters for glass, gas shut off valves and identification numbers on buildings.

Plate boundary

The boundary or margin between two tectonic plates.

Effects (Kobe Earthquake)

The effects of this earthquake were catastrophic for a HIC. Despite some buildings having been made earthquake proof during recent years many of the older buildings simply toppled over or collapsed. A lot of the traditional wooden buildings survived the earthquake but burnt down in fires caused by broken gas and electricity lines. Other effects included; • More than 5000 died in the quake • 300,000 were made homeless • More than 102,000 buildings were destroyed in Kobe, especially the older wooden buildings. • Estimated cost to rebuild the basics = £100 billion. • The worst affected area was in the central part of Kobe including the main docks and port area. This area is built on soft and easily moved rocks, especially the port itself which is built on reclaimed ground. Here the ground actually liquefied and acted like thick soup, allowing buildings to topple sideways. • Emergency aid for the city needed to use damaged roads but many of them were destroyed during the earthquake. • Raised motorways collapsed during the shaking. Other roads were affected, limiting rescue attempts. • Many small roads were closed by fallen debris from buildings, or cracks and bumps caused by the ground moving. • The earthquake occurred in the morning when people were cooking breakfast, causing over 300 fires, which took over 2 days to put out.

Ground deformation (volcanoes)

The movement of magma within the crust can deform the ground above. This has been witnessed at Yellowstone beneath Yellowstone Lake. This swelling of the volcano signals that magma has collected near the surface. Scientists monitoring an active volcano will often measure the tilt of the slope and track changes in the rate of swelling. Mount St Helens showed this prior to its eruption in 1980.

The plates and plate margins

The tectonic plates are made up of different materials, and there are 2 broad types: Continental crust is thicker, older and lighter, and is composed mainly of Granite. It is 22 mi (35 km) thick on average and less dense than oceanic crust. Continental crust is more complex than oceanic crust in its structure and origin and is formed primarily at subduction zones at destructive plate margins. Oceanic crust is younger and heavier, and is mainly composed of basalt and Gabbro. It is mainly formed at constructive margins or spreading mid ocean ridges.

Government

Their governments are often stable and democratic and have lots of agencies that can help during an emergency. Being democratic means that the public can put pressure on the government to have life safe buildings that survive natural disasters, or makes then want to respond quickly as it will help get the politicians votes.

A natural hazard

There are many natural events around the globe that do not occur in close proximity to people so do not pose a hazard. When natural events occur close to large or vulnerable populations we have a natural hazard.

Natural factors

Things like rock type (geology) in an earthquake, the shape of a coastline in a tsunami, the height of the land hit by a tsunami can influence the effects. For example, a gently sloping coastline will often suffer more damage than a steep coastline in a hurricane's storm surge. It is known that generally earthquake shaking in soft sediments is larger and longer than when compared with the shaking experienced at a "hard rock" site. Softer sediments are more likely to liquefy too, which can contribute to building collapse.

Prevent

This could be preventing damage to buildings etc. through strict building rules.

Level of development of the place

This determines how much money is available to prepare for the event in advance in terms of predicting the hazard and preparing people to cope with it, and also determines how the country responds after the event, wealthy places tend to respond quicker. High Income Countries (HIC) are generally much better at preparing and responding to natural hazards

Frequency

This is how often the hazard occurs. The more often a hazard occurs generally the more prepared people are, and the more used to coping they are. Large earthquakes and volcanic eruptions are generally very rare events in terms of a human lifespan so when they occur they can surprise. Floods are often regular events, large parts of Bangladesh flood every year for example. In this event people can adjust their buildings and lives to cope with the risk associated.

Population density and distribution

This is the number of people in an area and where they are. Generally, the greater the number of people in an area, the greater the potential for disaster. Therefore, an earthquake in Alaska will have less impact than one which hits a more densely populated area such as San Francisco. The Pacific Ring of fire covers a 40,000km horseshoe shape and has around 90% of the world's earthquakes and 452 volcanoes. Hundreds of millions of people live in this zone, including over 20 million people close to Popocatépetl volcano in Mexico.

Responses (Kobe Earthquake)

Water, electricity, gas, telephone services were fully working by July 1995 and the railways were back in service by August 1995 A year after the earthquake, 80% of the port was working but the Hanshin Expressway was still closed. By January 1999, 134,000 housing units had been constructed but some people still had to live in temporary accommodation. New laws were passed to make buildings and transport structures even more earthquake proof. More instruments were installed in the area to monitor earthquake movements. Most new buildings and roads have, in the last 20 years, been designed to be earthquake proof, schools and factories have regular earthquake drills, etc. Despite this, many older buildings still collapsed or caught fire. This led to many blocked roads and massive problems of homelessness. Electricity and water supplies were badly damaged over large areas. This meant no power for heating, lights, cooking, etc. Clean, fresh water was in short supply until April 1995. The government and city authorities were criticised for being slow to rescue people and for refusing offers of help from other countries.

Earthquake proof building

We can also plan for earthquake and volcanic activity. Prior to events we can plan where we will or will not allow building. Preventing building on softer sediments can protect people from the worst of the shaking and liquefaction during earthquakes for example. Plans should also be in place prior to events so that emergency services know what to do during a volcanic or earthquake event

The UK is NOT becoming more extreme. Give one example as to how.

it's not the weather that is becoming more extreme it's just that we are less able to deal with these events which leaves us vulnerable.

Magnitude

the size of the event massively affects the impact it has. A hurricane of magnitude 5 on the Saffir Simpson scale will have more impact than that which has a magnitude 3, whilst every step up the Earthquake Richter scale represents a 10 fold increase in damage and a 30 fold increase in energy released.

Long term recovery (Haiti Earthquake)

• The EU gave $330 million and the World Bank waived the countries debt repayments for 5 years. • The Senegalese offered land in Senegal to any Haitians who wanted it! • 6 months after the quake, 98% of the rubble remained uncleared, some still blocking vital access roads. • The number of people in relief camps of tents and tarps since the quake was 1.6 million, and almost no transitional housing had been built. Most of the camps had no electricity, running water, or sewage disposal, and the tents were beginning to fall apart. • Between 23 major charities, $1.1 billion had been collected for Haiti for relief efforts, but only two percent of the money had been released • One year after the earthquake 1 million people remained displaced • The Dominican Republic which neighbours Haiti offered support and accepted some refugees.

Impacts (Haiti Earthquake)

•316,000 people died and more than a million people were made homeless, even in 2011 people remained in make shift temporary homes. Large parts of this impoverished nation were damaged, most importantly the capital Port Au Prince, where shanty towns and even the presidential palace crumbled to dust. 3 million people in total were affected. Few of the Buildings in Haiti were built with earthquakes in mind, contributing to their collapse •The government of Haiti also estimated that 250,000 residences and 30,000 commercial buildings had collapsed or were severely damaged. The port, other major roads and communication links were damaged beyond repair and needed replacing. The clothing industry, which accounts for two-thirds of Haiti's exports, reported structural damage at manufacturing facilities. It is estimated the 1 in 5 jobs were lost as a result of the quake •Rubble from collapsed buildings blocked roads and rail links. • The port was destroyed • Sea levels in local areas changed, with some parts of the land sinking below the sea • The roads were littered with cracks and fault lines