The samoa-tonga tsunami

The samoa-tonga tsunamiAbstractOn the 29th September 2009 a order 8.0 seism occurring on the ou conditionost rise of the Tonga Trench generated a huge tsunami. The tsunami s motortruck Samoa, Ameri contribute Samoa and Tonga with devastating consequences. Waves which reached up to 7.4m struck the coastlines of the islands just sensation minute subsequently the initial underestimated tsunami marvelous. The tsunami killed at to the lowest class 182 people. It had a boastful fix on the populations of every utmost(predicate) the islands and besides had a sizeable impact upon the environment especially red coral reefs. Cases of breakbone fever fever and leptospirosis disease accept increased and there is expected to be a long verge impact upon the regions economy.IntroductionOn the 29th of September 2009 a bulky temblor of magnitude 8.0 occurred in the vicinity of the northern closing curtain of the Tonga Trench. This earthquake triggered a tsunami which had a large sc ale impact on the islands of Samoa, Ameri whoremaster Samoa and as well in Tonga. It caused many fatalities and devastated many aras. The pictorial possibility although scarce directly affecting a small region does meet a global significance. How the possibility of such a hazard was treated beforehand(predicate) and how people responded during and after(prenominal) it occurred can be used as a model to show the impacts of future similar hazards non only in this region, but in others crossways the earth. This report examines the cause, consequences and impact of the earthquake generated tsunami. It excessively valuees the human reply and whether the scale of the tsunami impact could cod been less.Cause of the TsunamiThe tsunami was generated by a magnitude 8.0 earthquake that struck at 174810 UTC at a foresight of 18km (United States Geological visual sense (USGS) 2009a). It occurred towards the northern of the Tonga Trench, 190 km south of Apia Samoa. Figure 1 shows its location. The Tonga Trench marks the boundary between the pacific and Australia plates. This is a merging(prenominal) plate boundary where the maritime Pacific plate subducts westward to a lower place the Continental Australia plate at the Tonga Trench. The rate of this subduction is the fastest to be enter worldwide with a maximum of 240mm per year at the northern end (Cousteau 2006). This makes this region one of the most seismically active in the world. Close to where the earthquake occurred the velocity has been measured to be 86mm per year (USGS 2009a) however in original worldwide plate tectonic movement this rate is still genuinely fast. The actual earthquake occurred on a thin ridge called the outer rise to the east of the Tonga Trench (Annunziato et al 2009). earthquakes occur in these regions, on the ocean side of a subduction zone, as normal charges ar ruptured when the oceanic plate is forced to flex as it bends under the continental plate. Thus it can be deduced that the earthquake was a normal fault rupture on the outer rise of the Tonga Trench.The earthquake was entangle across the islands in the region and was describe to defend shaken the ground for up to 3 proceedings (Adetunji and Gabbat 2009). In Iliili and Tafuna, American Samoa, the excitement was measured as reaching IV. According to the USGS modified Mercalli Intensity Scale (2009b) this would mean it would have been felt by most with the disturbance of objects such as windows and doors, standing(a) vehicles being noticeably rocked and a sensation like a heavy truck striking a building. A higher intensity was felt in Apia, Samoa of V but it was felt strongest in Faleniu, American Samoa with an intensity of VII (USGS 2009a). This could have resulted in considerable damage in bad built or badly designed buildings however there argon no reports that any damage was caused by the earthquake before the tsunami hit.The TsunamiTsunamis are generated by a sudden vertical dis placement of ocean piddle. In this instance an earthquake rupture in the sea floor caused piddle to be pushed upwards. This water collapses producing a tsunami. Through deep water the tsunami moves promptly with speeds up to 500 km/h but high school of the waves are usually less than 1m. As it nears shore the tsunami slows because of decreasing water depth but is compressed upwards thus growing in height. These waves are then capable of pushing far seaward (Keller and Blodgett 2008).The Pacific Tsunami ensample Centre first sent out an alert 16 minutes after the earthquake. It had, however, an underestimation of the earthquake magnitude 7.1 and so it was only a green alert. It was not until 20 minutes after the earthquake that the alert was scaled up to orange (Annunziato et al 2009). Both these alerts however would have come too late to help those in the regions first in the tsunamis path. Reports that water began to retreat from coastal areas beyond the coral reefs (Mer cer 2009) shows the tsunami was approaching Samoa presently after the populacequake. This report also suggests the tsunami first struck Samoa shortly after 700 am topical anesthetic time or 1800 UTC. The minute time for the first tsunami waves to hit Samoa is thought to be around 17 minutes after the earthquake (Annunziato et al 2009) or 1805 UTC. variant sources provide various data for the heights of the tsunami waves. The USGS (2009a) report, lists recorded wave heights as being 314cm in Pago Pago, American Samoa and 140cm in Apia, Samoa. It also detail the distance the tsunami travelled with it reaching Wellington, New Zealand where it was 11cm in height. The BBC reported waves of 5m in height (Mercer 2009) whilst the New Zealand Herald informed its readers that the island of Niuatoputapu, Tonga, experienced wave heights of 6m (Tahana 2009). With many of the sensors for measuring tidal height in the region not functioning, Annunziato et al (2009) carried out many calculatio ns so as to try and visualize actual wave height. Their results revealed tsunami heights of above 6m in some areas including 7.4m in Alaufu, American Samoa. There are also different reports on the limit to which the tsunami travelled inland causing damage. The Guardian reported the damage extending 100m onshore in Samoa (Adetunji and Gabbatt 2009) where as in eastern Samoa the tsunami caused damage up to 330m inshore (NASA Earth Observatory 2009). In American Samoa there are reports of water surging 1km inland (TVNZ 2009). By utilising all of this data it is evident that this was a large tsunami the impact of which was devastating.The Tsunami Impact and ConsequencesThe tsunami had a large impact upon the islands of Samoa and American Samoa and also proved to be destructive to the island of Niuatoputapu, Tonga. There were at least 149 killed in Samoa, 24 in American Samoa and 9 in Niuatoputapu (USGS 2009). In total it was reported to have affected around 32000 people and left ha nd wing close to 3000 homeless (Atayman 2009). Devastation was widespread with the destruction of tens of resolutions. Lalomanu, a small town come holiday resort in south-eastern Samoa, was flattened by the tsunami (Mclean 2009). It was do up around 100 homes and resort huts, the majority of which were destroyed. The village of Poutasi in south-western Upolu, Samoa was another that suffered large scale destruction (TVNZ 2009). Radio New Zealand (2009) reported that along the south coast of Upolu the majority of resorts and hotels were destroyed. American Samoas main village of Pago Pago was completely devastated with only the foundations of buildings being left and a large degree of flooding. On a greater scale all of western American Samoa was left with no power. Lieutenant G all overnor Faoa Sunia of American Samoa reportedly verbalise that water was limited in some areas overdue to damage to the water system (Samoa password stave 2009). In Niuatoputapu, home to just over 100 0 people, 90% of homes had been ruined and the hospital was also badly discredited (Tahana 2009).The long term consequences of the tsunami depart be substantial. Not only exit infrastructure have to be redeveloped but other factors are pass to be problematic. The loss of homes content people have been forced to suffer outdoors. This has resulted in people becoming more at risk of dengue fever. The fever is spread by mosquitoes and so a lack of encourage means people are more likely to get bitten. American Samoas only hospital has confirmed that there has been an increase in patients misfortunate from dengue fever with 62 confirmed cases in October and the first devil deaths from the disease in 2009 (anon 2009). The risk of polluted water being intoxicated is also greatly enhanced by the poor living conditions. Leptospirosis, a disease spread by the contamination of water by the urine of rats and other species has also seen a rise in confirmed cases in American Samoa, accord ing to the same report.The economic impact is going to be significant in the longer term. People from the rural areas of Samoa are aquiline on agriculture, fisheries and eco-tourism (FAO 2009). Areas of vegetable cultivation were devastated and the tsunami swept away fishing boats and fishing gear. The destruction of holiday resorts around the coasts of the islands and that their owners are fearful of returning means many tourists are likely to look elsewhere (Coopes 2009).The environmental impacts of the tsunami were also extensive. The Samoa Tsunami Rapid Environmental Impact Assessment Report (Ifopo et al 2009) lists very much of the damage caused and what damage was expected. It includes septic tank defilement, solid waste pollution and salinisation pollution which occurred in many areas. Salinisation pollution is going to be a significant impact to the agricultural industry as crops may emit to grow in soil with a high salt concentration. It also details that there was fore shore and beach erosion, damage to wetland areas and in particular mangroves. ravish to ecosystems extended beyond the coast with marine protected areas and no pass on zones heavily impacted. Coral reefs were also devastated. The Associated Press (2009) reported that some coral reefs had been obliterated whilst others may not be able to recover.Response to the Earthquake and TsunamiThe first tsunami alert was issued 16 minutes after the earthquake. This does appear to be relatively fast considering the data for the earthquake had to be received and analysed. tho the first alert was green the lowest alert level due to the earthquake magnitude being underestimated. It wasnt until 20 minutes after the earthquake when the alert was upgraded to orange by which point the tsunami had already struck the Samoa islands. more people didnt realise the earthquake could have generated a tsunami and thus a couple of(prenominal) moved to higher ground (Driscoll 2009). It is therefore apparen t that a express and more accurate response to the earthquake was required so as to have notwithstandingd at least some of the lives that were lost. As this could save lives in the future further investigations into methods on how to analyse earthquakes more rapidly are worthwhile.Aid response for the victims of the tsunami was issued within 2 days. The US, New Zealand and Australia provided the initial help with them all sending in planes to provide supporter and assess the overall damage, the US also sent in a send out from their naval fleet to assist (Atayman 2009 Australian Government Department of denial 2009). The American Samoa Power Authority (ASPA) delivered water to those who were affected by water shortages (Samoa word staff 2009) and the Red Cross set up camps for those who had been left homeless (Mercer 2009). The New Zealand Air Force provided medical supplies, medical teams and temporary worker morgue facilities to assist the hospital in Apia, Samoa (Young 2009 ). By October 8th all of Samoa was reconnected to the electricity grid and the main water pipes had been fixed as particular in the 7th United Nations Office for the Coordination of Human Affairs (OCHA) fleck report (2009b). The report informed that roads had been cleared in Samoa and Tonga and airports were functional. fiscal aid was provided by governments and other organisations worldwide. Using information from OCHA situation reports 6 by means of to 9 and also 11 (2009a 2009b 2009c 2009d 2009e) some of the funding provided can be listed as coming from the European Union (over $2 million), the lacquer International Cooperation Agency ($220 thousand), Australia ($874 thousand for Niuatoputapu), New Zealand (over $1.1 million), the European Commission ($ one hundred fifty thousand for Samoa) and the Asian Development Bank ($1 million). It is evident that the response to the tsunami was fast, well funded and efficient.EducationWhen researching the initial response to the earthq uake it was found that local people had previously been uninterested in the dangers of a tsunami (Driscoll 2009). This is likely to have been due to there being no living memory of the last significant tsunami which occurred in 1917 (Mataafa 2009). If they had knowledge of the consequences of a large earthquake occurring in the ocean they may have responded more cursorily by pitiable to higher ground. In this case in order to have saved lives it would have been essential for the local people of Samoa, American Samoa and Tonga to react quickly as the tsunami alert came too late. By educating people on the affects of earthquakes and how they can generate earthquakes it may be possible to save lives in the future. finaleThe 29th September Samoa Tonga tsunami devastated the islands and many of the people living on them. It was caused by a magnitude 8.0 earthquake which occurred on the outer ridge of the Tonga Trench. The Tsunami killed at least 182 people and affected thousands more. Much of the islands infrastructures were destroyed and the tsunami also had a significant environmental impact especially upon coral reefs. Long term consequences have already been seen with an increase in cases of dengue fever and leptospirosis disease. economically the impacts are also going to be long lasting. The destruction of livelihoods whether it is through fishing, agriculture or tourism will be widespread. It was found that the initial tsunami alert issued was the lowest level and wasnt upgraded until after the first tsunami waves hit. The response in the days following the tsunami however was quick effective and well funded. By educating people especially in areas where the risk of tsunami is high it is probable that lives will be saved in the future.ReferencesAdetunji, J. and Gabbatt, A. (2009) Samoa tsunami 100 feared dead on Pacific islands. Guardian, internet 30 September. open at http//www.guardian.co.uk/world/2009/sep/30/samoa-tsunami-pacific-earthquake Accessed 5 November 2009.Annunziato, A., Franchello, G., Ulutas, E. and De Groeve, T. (2009) 29 September 2009 Samoa Tsunami, (pp 70 of 2009). Luxembourg, Office for Official Publications of the European Communities.Anon (2009) Dengue Fever in American Samoa rises after Tsunami. New Zealand Herald. internet 9 November. operable at http//www.nzherald.co.nz/samoa-tsunami/news/article.cfm?c_id=1502844objectid=10608167 Accessed 12 November 2009).Associated Press (2009) Tsunami in Samoa takes bell shape on coral. New Zealand Herald. internet 2 November. Available at http//www.nzherald.co.nz/marine/news/article.cfm?c_id=61objectid=10606655 Accessed 12 November 2009.Atayman, B. (2009) Tsunami deaths likely to rise in Pacific islands Villages and vacation resorts destroyed. The Windsor Star. internet 30 September. Available at http//www.windsorstar.com/news/ over+killed+tsunamis+smash+Pacific+islands/2049879/story.html Accessed 6 November 2009.Australian Government Department of Defence (2009) ADF support to Samoa update. Defence Media Release. internet 1 October. Available at http//www.defence.gov.au/media/DepartmentalTpl.cfm?CurrentId=9535 Accessed 12 November 2009.Coopes, A. (2009) Tsunami-hit Samoa braces for tourism slump. news.com.au, internet 7 October. Available at http//www.news.com.au/story/0,27574,26178055-23109,00.html Accessed 12 November 2009).Cousteau, F. (2006) Atlas of the Oceans. In Ocean The Worlds furthest Wilderness Revealed, pp 480 481. London, Dorling Kindersley Limited.Driscoll, J. (2009) Lessons from Samoa Local researcher part of team sent to tsunami zone. times Standard. internet 3 November. Available at http//www.times-standard.com/ci_13701412?source=most_viewed Accessed 12 November 2009.FAO (2009) Recent natural disasters in Asia and the Pacific Samoa, Tonga, American Samoa, the Philippines, Indonesia and Vietnam. online (updated 2 October 2009) Available at file transfer protocol//ftp.fao.org/docrep/fao/meeting/017/asia_emerg.pdf Accessed 12 November.Ifopo, P.E., Atherton, J., Miller-Taei, S., Anderson, P., Suaesi, T., Steffen, J., Paisley, S. And Sherley, G. (unpublished) Samoa Tsunami Rapid Environmental Impact Assessment Report. internet 14 October. Available at http//www.sprep.org/att/irc/ecopies/countries/samoa/171.pdf Accessed 12 November 2009.Mataafa, T. (2009) Tsunami scientist presents findings of Sept. 29 wave. Samoa News. internet 24 October. Available at http//www.samoanews.com/viewstory.php?storyid=10111 Accessed 13 November 2009.Mercer, P. (2009) Samoas tsunami death toll rises. BBC News, internet 2 October. Available at http//news.bbc.co.uk/1/hi/world/asia-pacific/8286635.stm Accessed 5 November 2009.Mclean, T. (2009) Searching ruins for reason to live after tsunami. The Daily Telegraph, internet 2 October. Available at http//www.dailytelegraph.com.au/news/searching-ruins-for-reason-to-live-after-the-tsunami/story-e6freuy9-1225781822624 Accessed 9 November 2009.NASA Earth Observatory (2009) Earthquake of f Samoa Generates Tsunami. online (updated 13 October 2009) Available at http//earthobservatory.nasa.gov/NaturalHazards/view.php?id=40532 Accessed 2 November 2009).OCHA (2009a) Samoa/Tonga Tsunami Situation Report No. 6. internet 6 October. Available at http//www.reliefweb.int/rw/RW single files2009.nsf/FilesByRWDocUnidFilename/AZHU-7WL2CX-full_report.pdf/$File/full_report.pdf Accessed 12 November 2009.OCHA (2009b) Samoa/Tonga Tsunami Situation Report No. 7. internet 8 October. Available at http//www.un.org.au/files/files/Samoa%20SitRep%20No%207%208%20Oct.pdf Accessed 12 November 2009.OCHA (2009c) Samoa/Tonga Tsunami Situation Report No. 8. internet 10 October. Available at http//www.reliefweb.int/rw/RWFiles2009.nsf/FilesByRWDocUnidFilename/MYAI-7WQ2JM-full_report.pdf/$File/full_report.pdf Accessed 12 November 2009.OCHA (2009d) Samoa/Tonga Tsunami Situation Report No. 9. internet 14 October. Available at http//www.reliefweb.int/rw/RWFiles2009.nsf/FilesByRWDocUnidFilename/EDIS-7WTR39 -full_report.pdf/$File/full_report.pdf Accessed 12 November 2009.OCHA (2009e) Samoa/Tonga Tsunami Situation Report No. 11. internet 22 October. Available at http//www.reliefweb.int/rw/RWFiles2009.nsf/FilesByRWDocUnidFilename/AZHU-7X42LF-full_report.pdf/$File/full_report.pdf Accessed 12 November 2009.Radio New Zealand (2009) Samoa disaster toll soars. internet 30 September. Available at http//www.rnzi.com/pages/news.php?op=readid=49414 Accessed 9 November 2009).Samoa news staff (2009) 8.0 quake hits Samoa islands. Samoa News internet 29 September. Available at http//www.samoanews.com/viewstory.php?storyid=9550edition=1254218400 Accessed 6 November 2009.Tahana, Y. (2009) Teams bother Tonga Victims. New Zealand Herald, internet 2 October. Available at http//www.nzherald.co.nz/samoa-tsunami/news/article.cfm?c_id=1502844objectid=10600831 Accessed 6 November 2009.TVNZ (2009) Over 100 feared dead in Samoa tsunami. internet 30 September. Available at http//tvnz.co.nz/world-news/tsunami-sir ens-wail-again-in-samoa-3041553/ photograph Accessed 9 November 2009.USGS (2009a) Magnitude 8.0 SAMOA ISLANDS REGION. online (updated 28 October 2009) Available at http//earthquake.usgs.gov/eqcenter/eqinthenews/2009/us2009mdbi/ Accessed 2 November 2009).USGS (2009b) The limited Mercalli Intensity Scale. online (updated 27 October 2009) Available at http//earthquake.usgs.gov/learn/topics/mercalli.php Accessed 2 November 2009).Young, A. (2009) NZ aid arrives in Samoa. New Zealand Herald internet 1 October. Available at http//www.nzherald.co.nz/nz/news/article.cfm?c_id=1objectid=10600651 Accessed 12 November.