The Hazards of Sumatran and Tsunami Waves - Essay Example

Earth Science Written Assignment Name: Institution: Abstract It is very common to hear that Sumatran and Tsunami waves have occurred in several regions nearing the oceans. These geo-hazards have made the economy of the affected countries to dwindle significantly. This has prompted the Geoscience Australia to compile documentation about them. This document researches and has attempts to answer several questions on how these geo-hazards happened, what were the hazards associated with them and if there could have been a prediction or prevention against the occurrence of the catastrophe. Introduction On 26th December 2004, the famous Indian Ocean earthquake happened. There was an undersea mega thrust earth-quake which happened at exactly 00:58:53 UTC. This geohazard is known by many scientists as the Sumatra-Andaman earthquake. Since it happened on 26th December, some call it the Boxing Day tsunami. (Math & Hamza, 2006). This earthquake inundated the neighboring coastal habitats with waves which had amplitudes as high as 30 meters (98 ft). This catastrophe remains one of the most deadly natural disasters that are recorded in the planet’s history. The Indonesian citizens were the hardest-affected citizens, after that Sri Lanka follows, then India, and Thailand countries. These waves had magnitudes which had an alarming range of Mw 9.1–9.3. This magnitude places this geo hazard the third largest earthquake has ever been practically recorded on the seismographs. This earthquake happened for the greatest period of faulting intervals ever experienced, of 8.2-10 minutes. This earthquake resulted into the whole planet vibrating at even 1 cm and triggering extra earthquakes to happen in areas which were distant like Alaska. Its epicenter was within Simeulue and the Indonesian land. This predicament of the affected individuals and nations provoked global charitable responses. A total of more than $14 billion was raised by the global population. (Kelly, 2004). These catastrophes were disastrous There are several hazards which are linked to this earthquake. Most of the damages resulting from the Sumatra-Andaman earthquakes were from the Tsunami it had provoked as opposed to the earthquake itself. The Tsunami earthquakes claimed over 230,000 lives in 14 countries. There are also some other hazards which were posed by the earthquakes. For example, in Port Blair (Andaman Headquarters) & Nicobar island (in India). These earthquakes and ensuing Tsunami resulted to significant damages on construction which comprised of building structures, harbors, overhead water containers, control towers in the seaports, and so on. Any vital structure, like, dam, bridge, hangar, and so on, was also subjected to minor damages and also their functionality were disrupted. The reinforced concrete constructions on the islands had the worst performance, although the traditional structures like the timbers and masonry structures were not very much adversely affected by this ground shaking. (ASCE, 2007) Banda Aceh, which is one of the Indonesian cities had 300,000 residents prior to this catastrophe had damages resulting from both the tsunami and the subsequent earthquake. Most of the casualties were from that city. Coastal regions were completely swept away by tsunami waves, which consequentially left piles of timber from the building infrastructure. Many non-engineering reinforced concrete constructions were structurally damaged, particularly in the first floor columns. Origin of the catastrophe The main generation system of that tsunami is as a result of displacement of significant volumes of water or marine perturbations. When the water was displaced, usually attributed to any earthquake, landslide, volcanic eruption, glacier calving or more infrequently by a meteorite and nuclear testing. These waves which were generated in this manner were then sustained by gravitation forces. Scientifically, tides aren’t involved in the formation of any tsunami. (Haugen & Harbitz, 2005) Sumatra is the largest island located in the western part of Indonesia. The Sumatra earthquake is believed to be an undersea mega up thrust earthquake. This earthquake was as a result of the subduction. This is a process that happens whenever the tectonic plates move under other tectonic plates. Instead of sinking vertically downwards, the oceanic plate in the Sumatra region takes a superficial dive beneath the continental plate. Thus, the continental plate is ever pressed sideways at approximately1.2 cm annually (1/2 inch annually), also gets dragged downwards at almost the same pace. The region on which these two plates overlie is referred to as the Sumatran Subduction Zone. (Margaritondo, 2005). The oceanic plate sub ducts below the continental plate. Then these two plates get stuck, or locked. While the lower plate gradually descends, it also drags the upper plate downwards, and thus deforms the earth surface beyond and builds up stress. The island which is nearing the trench will the start to subside gradually, as the distant inland slowly becomes uplifted. When the stress which is building up exceeds the locking friction, these plates unexpectedly break away from each other then the upper plate slips back. The resulting abrupt slip causes an earthquake. The island then would pop back upwards, and the land which is further from the ocean unexpectedly subsides. Such swift displacements of the oceanic floors eventually generate the tsunami. (Margaritondo, 2005). A tsunami can’t be accurately predicted; even when the intensity and locality of the earthquake are is identified. Oceanographers, Geologists and seismologists analyze every earthquake on the basis of several factors which might or might not notify a tsunami alarm. Although, there are several alarming signs of an imminent tsunami, and thus an automated system could issue warnings straight away following an earthquake in time and this could have saved the lives of many. One of the most remarkable systems applies the use of the bottom pressure sensors. These sensors are connected to some buoys, which are usually used in monitoring the pressure of the over-lying water columns in these regions. (Haugen & Harbitz, 2005) Places which have high Tsunami risks are usually using the tsunami warning systems in warning their residents before these waves reach the land. Also if there were warning signs which were indicating the evacuation routes, the situation could not have been that worse. In Japan, the citizens are constantly well-educated concerning the occurrence of any earthquake and tsunami. Also alongside the shorelines in Japan, there are tsunami caution symbols which always act as reminders of these catastrophe and networks of several caution sirens, normally at the peak of some cliffs of the surrounding mountains. Tsunami warning systems monitor ocean seismic activities. An adequately large earthquake degree and additional information trigger a tsunami alarm (Math & Hamza, 2006). If such methods could have been used, the catastrophe could have been detected and several lives could have been saved. Conclusion The occurrence of the Sumatran earthquake and associated tsunami happened in 26th December 2004. These earthquake Sumatran shakings and ensuing tsunami damaged several building structures, harbors, overhead water containers, control towers in the seaports, and so on. This has made the people involved to incur huge losses and many lives have been lost. These geo-hazards could not have been precisely predicted but if these could have had public awareness on the geo hazards, then the destruction could have been reduced. Also if they had Tsunami warning systems, they could have been able to suspect any eminent Tsunami and many lives could have been saved. Reference List ASCE. 2007. Impact of great December 26, 2004 Sumatra Earthquake and Tsunami on structures in Port Blair. Retrieved from http://ascelibrary.org/action/showAbstract?page=128&volume=21&issue=2&journalCode=jpcfev& Haugen & Harbitz. (2005). Fundamental mechanisms for tsunami generation by submarine mass flows in idealized geometries. Marine and Petroleum Geology 22 (1–2): 209–217. doi:10.1016/j.marpetgeo.2004.10.016 Margaritondo. (2005). Explaining the physics of tsunamis to undergraduate and non-physics students. European Journal of Physics 26 (3): 401. Bibcode:2005EJPh...26..401M. doi:10.1088/0143-0807/26/3/007 Kelly. (2004). Ammianus and the Great Tsunami. The Journal of Roman Studies 94 (141): 141–167. doi:10.2307/4135013 Math & Hamza . (2006). Tsunami: Psychosocial aspects of Andaman and Nicobar islands. Assessments and intervention in the early phase. International Review of Psychiatry 18 (3): 233–239. doi:10.1080/09540260600656001 Read More