Posted: June 27th, 2015

Natural disasters

Introduction

Natural disasters are rapid and instantaneous occurrences that cause extreme devastation to the environment and to the socio-economic systems. The world is prone to many natural disasters though the the socioeconomic impacts have been mitigated. It is estimated that a third of the world economic cost is channeled towards prediction and mitigating disasters. Death tolls vary from one catastrophe to another as some countries vulnerable to these disasters recording a large number of deaths. An example is japan as it is well known to have experienced frequent and different types of disasters in the past. We shall discuss earthquakes,floods and volcanic eruption in this paper (Kisslinger 1974)..

Earthquakes

Earthquakes have rocked the earth for a long period of time. Scientists do not have exact reasons why earthquakes occur but they know that it occurs when plates shift positions or collide. It is clear that some areas of the earth experience frequent and deadly earthquake more than others, an example is japan.scientists study earthquakes using seismographs to locate the epicenter and for future predictions. Scientists have observed that different regions may have different earthquake precursors therefore to avoid faulty warnings the tools used should monitor a wide range of parameters for vulnerable areas of the world.predictions are made using data and observations and dense networks of epicentral areas, in the future monitory of small earthquakes of six magnitudes and below is important since the techniques would help in predicting large future earthquakes for earthquake control. Today experiments a are done for future earthquake control in Colorado rangelands though further studies are still necessary for reality in terms of the understanding of the physical processes involved, magnitudes, rock characteristics. This knowledge will play a significant role in earthquake control modification models and the earthquake feasibility. The success of future predictions depends on the manpower commitment to seismological programs (Kisslinger 1974).

California, San Fransico, 1906

San Fransico was occupied mainly by Spanish from Mexico. By 1906 the population was about half a million. The city experienced small yearly earthquakes and everyone knew about earthquakes.the city is built on the pacific and north America tectonic plates over the San Andreas fault stretching for about eight hundred miles and sixteen kilometers deep (Prokos 2009) .There are many other fault lines in the region. Each year scientists record about 2o,ooo strong tremors. On 18^th April 1906, a great earthquake of 7.8 magnitude hit the city at 5.00 am while people were still sleeping killing three thousand people. The underling plates slide horizontally past each other.chimneys crumbled into pieces, buildings collapsed and crushed people while some were trapped and street split into two. Even several days after the quake the city was still in flames as the fire fighters could not extinguish the flames. Many people died instantly while others drowned in the flooded buildings as they could not escape.the aftershock flattened the already damaged buildings disrupting the recovery process (Weil 2013).

The calamity caused death of thousands of people and almost al material wealth was destroyed by the fire. It caused both administrative and economic mess, the inhabitants described the disaster as a fire storm because the most destruction was done by the fire. The American and British insurance company settled the cost of losses at 65.3% and 34.3% (Roder 2011) respectively. After this disaster the chiefs of major insurance companies pushed for major changes to improve the building codes and the infrastructure (Roder 2011).The population of San Francisco city in January first 2010 was about 809, 249 as extrapolated from us censes carried out in 2000.

Volcanoes

The earth was formed over four hundred years ago from a hot mess that split from the solar system. The force of gravity separated the earth into layers as heavier materials settled in the center and light on the outer surface.volcanoes are known to release the pressure of the molten magma once the overlying rocks can no longer contain the pressure through eruption. There are two kinds of volcanic mountain , one is active and is expected to erupt in the future while the other is dormant are less likely to erupt in the future. Some erupt for months and years while others erupts quickly and stop. A volcanic eruption is one of the most fear natural disasters because of their extreme destructive nature of people, land, vegetation, landscape, buildings, roads and infrastructure. Major volcanic eruptions occur eve4ry killing and injuring inhabitants of the volcanic active regions.apart from the visible dangers of volcanoes, they can be a poisonous killing living organism in case of contact. The dark ashes form the volcanoes may have several mixtures of gases resulting in air pollution (Thompson, Graham , and Jonathan Turk 2007).

Prediction and risk assessment

Many volcanoes are active therefore the geologists must predict an eruption to reduce potential disasters. It is necessary that one understand the tectonic environment of of a given region as a first step for prediction, this is due to the relationship between an eruption and the geology of that particular area. The frequency of eruption in the past and magnitude is important in future risk assessment. Regional predictions can estimate he time of a future earthquake but cannot predict the intensity.short term predictions are more accurate than regional predictions, this is because short term focuses on detecting signs for a specific time for a specific active volcano. Some of the signs are changed on the surrounding land i.e. smoke or gas emissions, temperature of the nearby hot springs and earthquake(Thompson, Graham , and Jonathan Turk 2007)..

The eruption of Mt St. Helens, 1980

Mt Helens erupted last in 1857. Two u.s. geologist predicted that the mountain would erupt before the end of the century due to the past frequent and violent eruptions. An earthquake of occurred below the volcano causing small eruptions   that lead to a greater eruption two months later. Geologist installed seismographs and surveying tools to record signs of the seismic activities. Sensitive sophisticated equipments wee used to monitor changes on the ground water composition and temperature increase prior to the may eruption it was observed that the mountain swell and increased in health due to the upward force of magma.The results showed that the mountain could erupt again therefore the government was advised to vacate the civilians to avoid loss of lives. These instruments were used in Philippines 1991 lives were saved. David Johnstone is one of the unlucky scientists whom have been caught of guard killed . The eruption flattened a vast area of thirty five by twenty kilometers, some people were engulfed by the dark clouds debris as they tried they tried to escape.the high temperatures melted the mountain ice resulting in strong mud flows that flattened the vegetation, moved vehicles and buildings. The mud reached the Columbia river where it destroyed the river biodiversity. Ash clouds of high temperature smoldered everything in their path. The area still shows the effects of the disaster though the vegetation is slowly regenerating. The forest service has managed to replant trees, especially on the plain ground (Thompson, Graham , and Jonathan Turk 2007).

Floods

Foods are natural occurrences that shape the landscape, ecological habitats and ecosystems. Floods can cause loss of lives and property destruction thus it is advisable for vulnerable regions to take steps necessary to predict and control floods. Poor land use methods both in the rural and urban areas can cause flooding.

Europe

Different regions of Europe have experienced major flood problems between 1998 and 2000 due to climate change, it is predicted that floods will increase in Europe as a result of the recent frequency . At least 25 billions of Euros insured economic losses experienced and about seven hundred fatalities. It was estimated that around 1.5% of the Europeans were affected by floods that covered a total area of 1m. Km while particular places were affected more than once(commission for the protection of the Danube river basin 2006). .

Danube river basin 2002

The flood affected the following countries: Germany, Austria, Czech republic, Hungary, Slovakia, Romania. The flash flood Suceuva that is northern Romania lead to the death of ten citizens, over sixteen thousand houses flooded, hundreds of kilometers of roads destroyed, and close to five hundred bridges destroyed. The destruction on infrastructure also affected communications well as causing damage to gas and electric network. Several municipalities in Hungary were affected by more than twenty thousand people vacated from their homes as 4,370 homes damaged. The presence of prevention structures and well executed emergency interventions minimized the possible overall damage. Emergency operations costed thirty three million Euros as ten point two Euros needed for rehabilitation.central parts of Slovakia were the most affected as 144 settlements and thousands of hectares flooded. Damages costed €36.2 million and emergency costs amounting to €2.2 million.the 2o communities in the Morava river basin, Czech republic were affected especial agriculture and infrastructure resulting in a €11.7 million damage cost. 10 000 homes and infrastructure destroyed in the lower and upper Austria, the total damage amounted to €3.1bilion. In Germany Inn, Traun, Regen, and Salzach tributary areas were slightly affected due to the regulating structures reducing a potential extended damage. The 2006 floods caused swelling of rivers and many abandoned their homes due to high water levels. This was the major flooding experienced in the Danube in the last 100 years. The international commission for the protection of the Danube area revised the hydrology of the area to develop ways to support the national preparedness. The report from this meeting proposed possible solutions and the way forward to minimize damage in the future International (commission for protection of Dandube river basin 2006).

Conclusion

The above discussed are just a few major natural disasters the world is facing. It is evident that disaster preparedness has reduced the magnitude of devastation in the past, therefore the world understand best that the only way to deal with these phenomena is through our commitment to improve the existing mechanisms to develop better mitigation measures with time.

References

International commission for protection of Dandube river basin,floods, 2006. Print.web 27 November, 2012. http://www.icpdr.org/main/issues/floods

Kisslinger, carl Earthquake predictions.physics today,Vol 27, no 3,pp 36-42,1974. Print.

Prokos, Anna. Earthquakes. Pleasantville, NY: Gareth Stevens Pub, 2009. Print.

Röder, Tilmann J. From Industrial to Legal Standardization, 1871-1914: Transnational Insurance Law and the Great San Francisco Earthquake. Leiden [u.a.: Martinus Nijhoff Brill, 2011. Print

Thompson, Graham R, and Jonathan Turk. Earth Science and the Environment. Australia: Thomson Brooks/Cole, 2007. Print.

Weil, Ann. Earthquakes. Costa Mesa, Calif.: Saddleback Educational Pub, 2013. Print