Evaluate the strategies used to reduce the impact of tectonic hazards. Tectonic hazards are comprised of earthquakes and volcanoes; they are named ‘tectonic hazards’ as it is ultimately the movement of tectonic plates that cause these events. These hazards have the potential to kill thousands and devastate the region it strikes. Although the main hazard causes destruction, events that follow can be equally, if not more, devastating, for example an earthquake can often trigger a tsunami.
Many strategies have been put forward to try and minimise the impacts and save lives, some have proved successful however, fighting the forces of nature has proved to be a difficult task. It’s not possible to prevent volcanic eruptions and earthquakes, however, careful management of these hazards can minimise the damage that they cause.
Prediction is the key aspect, as this gives people the time to evacuate and make preparations for the event. As a volcano becomes active, it gives off numerous warning signs that are picked up by volcanologists; hundreds of small earthquakes are caused as magma rises through cracks in the earth’s crust, temperatures rise as activity increases and the volcano will start to release gases.
The techniques available for predicting and monitoring volcanic activity are becoming increasingly accurate, and many volcanoes are constantly being monitored, such as Mount Etna. Anyone sharing a region with a volcano should have a detailed plan in preparation for an eruption, which could include having an emergency supply of basic provisions, being able and ready to evacuate residents and emergency funds available as the inactivity of a volcano can provide a false sense of security thus residents should always be prepared for an eruption. Unlike earthquakes, positive effects can occur as a result of a volcanic eruption as well as negative. However, the devastating effects of a volcanic eruption usually outweigh the positive impacts.
Mount St Helens is a volcano that is located on the plate boundary between the Juan de Fuca plate and North American plate, and after the eruption in 1980, the area has become a regularly visited tourist destination. However, 63 people were killed, mainly due to poisonous gases, lahars destroyed over 200 homes, 12% of the total crops in the area were destroyed and out of 32 known species in the area, only 14 are known to have survived.
Management strategies were quick to be put in place and firstly an exclusion zone was set up consisting of red zones; where no activity was allowed and a blue zone where certain activities were allowed, such as farming. In total, 2000 people were evacuated to prevent any further casualties. There were several immediate responses that were carried out in order to manage the impacts of Mount St. Helens, these included; the government providing 2 million gas masks to avert any more fatalities related to poisonous gases and ash fall and the national guard flew helicopter rescue missions into the blast zone for two weeks and rescued 130 people.
These immediate management strategies prevented any further deaths and focused mainly on getting people out of immediate danger. Long term management strategies for the Mount St. Helens eruption of 1980 include; the replanting of over 10 million trees in the area, the Toutle, Cowlitz and Columbia river were dredged and the volcano is now monitored constantly by the USGS and clear plans have been made to prepare and warn people beyond the immediate blast zone to make them aware of the risks of ash clouds.
The replanting of millions of trees will eventually bring back more species of mammals and re built destroyed habitats, and the constant monitoring of the volcano will save lives in the future if an eruption was to occur again. Mount St. Helens is located in an MEDC, thus it was expected that the effects would be resolved fairly quickly, as they have the finances and government support to do so, however, in an LEDC it is much more difficult to manage the impacts of a large volcanic eruption.
The Montserrat volcanic eruption of 1995 resulted in 2/3 of the island being covered in ash, 50% of the island had to be evacuated to the north of the island and forest fires and tsunamis were caused due to pyroclastic flows. Long term effects include; 2/3 of the island has been declared a danger zone and many people who left the island never returned meaning the population dropped from 11000 to 4000.
As the island is located in an LEDC, it was much harder to manage the effects. £41 million was given by the British government to aid the island, they also gave money to help rebuild the north side of the Island and build new houses for the remaining population. A Volcanic observatory was also built to monitor the volcano. However, scientists have argued that further development would be a waste of time as they are still not sure whether another eruption will occur and if it would wipe out the whole island.
Therefore, the effects of a volcanic eruption can be managed through immediate responses, that prevent any further casualties and through long term responses that help to rebuilt the area and eliminate the consequences of the impacts. Although, managing impacts is much easier if the volcano is located in an MEDC, as there is more financial support. Similarly, an earthquake can cause severe damage just like a volcano, however the effects depend on; the depth of the focus, the nature of the material above, the relief of the land and the number of people occupying that region.
Earthquakes are not as easy to predict as eruptions, however there are still multiple ways of monitoring the chances of an earthquake. Laser beams are used to detect plate movement, a seismometer is used to pick up the vibrations in the earth’s crust and radon gas is monitored as it escapes from the Earth’s crust, all of which may suggest an earthquake. Although, many of these prediction techniques are not completely reliable, thus planning and preparing for an earthquake is very important. People living in earthquake prone zones need to know what to do in the event of an earthquake, therefore training people is strongly advised, and holding earthquake drills and educating via radio and TV.
People may put together earthquake emergency kits and store them in their homes; they may include first-aid kits and tinned food. Earthquake buildings, such as the Transamerica building in San Francisco, have been constructed and are designed to absorb the energy of an earthquake and to withstand the movement of the earth through construction methods such as cross-bracing.
The Kobe earthquake of 1995 caused devastation in Japan, yet before this earthquake, the country was considered to be well prepared for a major earthquake. Japan has an earthquake preparedness system where school children were put through emergency fire and earthquake drills four times a year, earthquake kits can be bought at supermarkets and the earthquake preparation programme resulted in a Disaster prevention day (September 1st) every year, however there were limitations to their management strategies. There were flaws in the preparedness system as seen from the people’s reaction during the earthquake, as many were seen running outside buildings in panic and were hit by falling debris.
The earthquake also revealed that the communication and coordination between politicians were inadequate. The official response was slow and there was a five hour delay before the army were mobilised and even then there were unsubstantial numbers of troops. Government also spent too long debating what would be the disaster zone before issuing emergency relief, they also spent too long accepting international aid. In conclusion, volcanic eruptions are much easier to predict and prepare for as the methods used are much more reliable, therefore the management strategies in theory should be successful.
However this tends to depend on how financially stable the country is, as managing an eruption is usually more successful in an MEDC, such as Mount St. Helens. On the other hand, earthquake prediction is much more unreliable than that of volcanic eruptions, making it much more difficult to be certain whether to alert the area and put their strategies into use. As witnessed in the Kobe earthquake, management strategies are not always successful, and better communication between government officials could have saved many lives.
