Earthquakes Abstract

Earthquakes

Abstract

Thispaper addresses current efforts that governments, geologists, localleaders and the international community have made towards earthquakerisk reduction on the earthquake-prone regions along the pacific.There is a distinction between those jurisdictions that putsufficient efforts to reduce earthquake risks and those that arelagging with respect to present and future efforts to reduce risksthat occur as a result of strong seismic waves. The differences inearthquake preparedness among different regions are caused by thedifferent risk profiles of the vulnerable areas, and also thediffering economic and political circumstances of the said regions.Through a comprehensive literature review, the paper explainsdifferent perceptions that have possibly affected the extent ofpreparedness to earthquakes hinter lands that border the pacific. Thefindings entail the information obtained from different secondary andprimary sources about the prevalence of earthquake-prone areas alongthe pacific and the level of preparedness.

Tableof Contents

Abstract 2

List of Figures and Tables 3

Introduction 4

Background to the Study 5

Objectives of the Study 5

Literature Review 6

Damaging perceptions of elected officials 6

Damage perceptions of engineering and building officials 7

Findings 7

Discussions 8

Conclusion 8

References 9

Listof Figures and Tables

Figure1:Pacific Ring of Fire

Table1:Earthquake on Earth by percentage for each Highly Seismic Region

Introduction

Beforeanalyzing the prevalence of earthquakes in the pacific, assessing thehazards and discussing some of the methods that have been applied toreduce risk, it is vital to explain how an earth quake occurs. Anearthquake’s focus is the location where rapture within the earth’slithosphere occurs and energy is released. The epicenter is the pointon the earth’s surface directly above the focus. Seismologistsclassify earthquakes in three categories based on the focal depthfrom the epicenter: shallow-focus earthquakes with depths of lessthan 70km, intermediate earthquakes with depths of less than 70km and300km, and deep-focus earthquakes with depths of greater than 300kilometers (Burke and Whilte, 2008). Earthquakes are recorded onseismographs, and the record of an earthquake is a seismograph. About80% of all earthquakes takes place in the circum-pacific belt, 15%within the Mediterranean-Asiatic belt, and the remaining 5% mostly inthe interiors of plates and long the oceanic spreading ridges. Morethan 900,000 earthquakes occur per year, with more than 31,000 ofthese strong enough to be felt (Burke and Whilte, 2008). The figurebelow indicates the pacific ring of fire.

Figure1: PacificRing of Fire

(Sridharan,2012)

Whenan earth quakes releases energy, the energy triggers seismic waves. Seismic waves move outwards in all directions from the focus of anearthquake. The energy released takes the form of body waves, whichtravel through the solid earth, the surface waves traveling along theearth’s surface

Table1: Earthquakeon Earth by percentage for each Highly Seismic Region

The Pacific-Belt

The Mediterranean-Asiatic belt

The rest of the world

Prevalence of earthquakes (%)

80%

15%

5%

(Burkeand Whilte, 2008)

Backgroundto the Study

Themotivation behind this research paper is the need to assessearthquake prone areas on the pacific, and then suggest the neededchanges that would reduce risks through change of policies andpractices. Thus, this paper investigates the seismic hazards on thepacific and the risk perceptions that characterize these earthquakeprone areas.

Objectivesof the Study

  1. Provide a basic explanation of how earthquakes occur, describe different types of earthquakes, and describe different types of seismic waves that cause earthquakes

  2. Identify areas along the pacific that have a highly prone to earthquakes

  3. Identify those areas that have comprehensive and working earthquake risk reduction strategies for the present and the future

  4. Identify areas that lack a working earthquake preparedness plan that works for the present and the future.

  5. Review literature that addresses the perceptions of earthquake risk by local leaders, building and construction engineers.

LiteratureReviewDamagingperceptions of elected officials

Accordingto Rogers, A. M (1996),there are different risk perceptions that characterize differentearthquake-prone areas along the pacific. The authors considerelected officials and engineering directors to be the most importantpeople in shaping perceptions about the extent to which theoccurrence of earthquakes poses risks to life and property (p.33). The authors address these concerns in form questions about theperceptions of the technical and political leadership about thepotentialities of risks within their jurisdictions. The majorfindings that lead authors found in their research is thatinformation about risk perceptions of elected leaders helps to depictthe broad political context of earthquake risk reduction. They alsofound that most areas along the pacific had a general awareness ofseismic risks in the region, with a somewhat greater level ofawareness in areas in western countries and the Far East than therest of the regions (p.38). Based on this research by Rodgers, mostrespondents reported reading about it in the newspapers and orthrough other electronic media. Thus, they had a rough idea of theseismic risks in their respective areas. However, some respondentsseemed to discount the risk. Whatever the risk perception, the threeresearchers found that elected officials had little concern about theearthquake hazards in their jurisdictions due to other pressingconcerns such as legislation on healthcare, immigration, housing, andwages.

Theresearch findings of Rodgers are consistent with similarinvestigations by Berke and Whilte (2008) in other areas of high tomoderate risk in other areas on the Californian coast in the UnitedStates. Berke and Whilte found that earthquake risk falls at the lessdreaded end and more accepted ends of the spectrum of attention tovarious by politicians and the general public. They concluded thatthe profile of responses by elected officials suggests a generalawareness of the potential for a moderate earthquake and a lessersense of potential for a high Richter scale earthquake. Somerespondents would rate all the risks associated with a potentialearthquake very highly while other gave them a low risk rating.Interestingly, they also found that elected officials in developedcountries along the pacific considered chemical risks the greatestrisk to the populace more than moderate earthquakes. Berkeand Whilte give two examples: the Washington City Officials, whoconsidered moderate earthquakes the third greatest risk, and theOregon officials who considered earthquakes the second greatest risk.

Damageperceptions of engineering and building officials

RobertoVillaverde (2006), in the book, FundamentalConcepts of Earthquake Engineering,considers the perceptions of building officials and constructionsengineers, in conjunction with seismologists the most importantbarometers for reducing the risk of earthquakes in future. Villaverdeconsiders these professionals a great source of invaluableinformation in assessing the potential risks of an earthquake onvulnerable areas along the pacific and adopting mitigating policiesto that effect. Unlike, the other authors discussed above, Villaverdeconsiders elected officials as secondary because such legislation mayenacted through direct means to address the sensitivities of thematter. Villaverde reached these conclusions after carrying out astudy in which building officials and construction engineers wereasked about the potential earthquake vulnerable classes of buildingin each jurisdiction. The findings were quite disappointing sincenone of the jurisdictions maintained building inventories. Theresponses that these officials provided only reflected theirprofessional impressions of potential vulnerabilities. Villaverdealso asked building officials and construction engineers to assessthe impacts of various earthquakes upon the different buildings intheir jurisdictions. The professionals collectively said that threeclasses of buildings are potentially vulnerable: (1) unreinforcedmasonry buildings (2) tilt-up concrete buildings built before 1975,typically used as warehouses, as light-industrial facilities of forother similar purposes and (3) reinforced concrete frame buildingsbuilt before the early 1960s, typically 3-10 storied buildings usedas offices, schools, or apartments. Villaverde finally reiterated thefact the officials linked up with seismologists to articulatedifferent seismic potentialities in their jurisdictions.

Findings

Thefindings of in this paper are a simply a report of the generalpreparedness of different jurisdictions along the pacific to thepotential risks of seismic destruction. These findings reflect thegeneral agreement of several authors whose views have been discussedin the literature review. Most areas along the pacific face a highseismic risk. However, the non-committal attitude of elected leadersto initiate mitigation measures to reduce the risk of earthquakescreates more danger to the populace. Like their leaders, peopleliving in most jurisdictions where there is a general awareness ofseismic potential do not consider it the biggest risk to life andproperty. However, professionals in building and constructionengineering in collaboration with seismologists are articulate aboutthe seismic potentialities and the types of structures at a greaterrisk of destruction.

Nowthat elected leaders have more influence on resource allocation, theyprioritize other concerns that seem more immediate than earthquakes.Thus, more regions along the pacific remain at risk of seismicdestruction and loss of lives. The international community throughthe United Nations depends on local commitment. With the currentstate of affairs, the international community ends only playing theinterventionist role rather than being part of risk reduction beforean earthquake occurs.

Discussions

Theopinions by expert authors on the potential of earthquakes to destroylives and property trigger significant concerns on the role of thelocal leadership in setting the pace for professionals and theinternational community (Olshansky, 1994). Unless local jurisdictionsalong the pacific classify earthquakes as one of the localpriorities, more seismic destruction is likely to be experienced infuture. Governments depend on the expert opinion of seismologists andconstruction engineers to develop a policy framework that guidespreparedness, risk reduction, and international rescue andhumanitarian interventions. The need for more direct legislation andmandatory budgetary allocations to reduce risk reduction initiativescannot be overstated. It is only through expert legislation that therisks posed by seismic potentials can be reduced. Politicians haveother concerns that they feel are immediate hence, they would ratheraddress them first at the expense of a more vulnerable populace toearthquakes. Furthermore, the international community responds basedon an existing framework as set out by the local leadership. In theevent that such policies are unsatisfactory, the United Nations islikely to invoke international statutes, which may not adequatelymeet the needs of locals. Co-ordination challenges are likely toarise during evacuation processes.

Conclusion

Communitiesresiding in earthquake-prone areas along the pacific should be awareof the risks associated with destructive seismic activity.Over-reliance on the local leaders has maintained an interventionistattitude rather than a proactive attitude that could save lives.Thus, direct participation of professionals such as seismologists,buildings experts, and construction engineers will provide the neededrisk reduction solutions commensurate with the potential risks. Infact the politicians only need to adopt laws that have a heavytechnical and professional input without unnecessary politicalposturing. Such a step will guarantee the allocation of resources torisk reduction measures without diverting them to other issues thatof more political concern.

References

Burke,K., and Whilte C (2008). Caribbean tectonics and relative platemotions. GeologicalSociety of America Memoirs,162,31-64.

Olshansky,R. B. (1994, July). Earthquake Hazard Mitigation in the CentralUnited States: A Progress Report. In Proceedings,Fifth US National Conference on Earthquake Engineering(Vol. 3, pp. 985-994).

Rogers,A. M. (Ed.). (1996). Assessingearthquake hazards and reducing risk in the Pacific Northwest(Vol. 1). USGPO.

Sridharan,V. (2012). IndonesiaEarthquake 8.7 Magnitude: What is Pacific `Ring of Fire`?.Available athttp://www.ibtimes.co.uk/indonesia-earthquake-tsunami-pacific-ring-fire-richter-326643

Villaverde,R. (2009). Fundamentalconcepts of earthquake engineering.CRC Press.