Ka Pili Kai

Ka Pili Kai

Addressing Coastal Hazards

University of Hawaiÿi Sea Grant College Program University of Hawaiÿi Sea Grant College Program University of Hawaiÿi Sea Grant College Program University of Hawaiÿi Sea Grant College Program University of Hawaiÿi Sea Grant College Program VVVVVol. 26,ol. 26,ol. 26,ol. 26,ol. 26, No. 4 No. 4 No. 4 No. 4 No. 4 Winter 2004/2005Winter 2004/2005Winter 2004/2005Winter 2004/2005Winter 2004/2005

Ka Pili Kai

Ka Pili Kai Ka Pili Kai Ka Pili Kai Ka Pili Kai Ka Pili Kai VVVVVol. 26 No. 4ol. 26 No. 4ol. 26 No. 4ol. 26 No. 4ol. 26 No. 4Contents

Ka Pili Kai – “things connected with the sea” highlights connectionsbetween people and our ocean environment. Lately when we think ofcoastal hazards, our minds turn to the December 2004 tsunami in theIndian Ocean. This disaster reminds us in Hawaiÿi of our intimateconnection with the sea; we are uniquely blessed by our environmentbut also vulnerable to a myriad of coastal hazards.

This issue of Ka Pili Kai focuses on understanding and addressingcoastal hazards in Hawaiÿi. Edison Gica describes the science behind atsunami and details facts every resident of Hawaiÿi should be familiarwith; while Yong Wei shares his research to improve tsunami warningsystems and update Hawaiÿi’s tsunami evacuation maps. Focusing oncoastal erosion, Zoe Norcross-Nuÿu and Dolan Eversole highlightsome of their current and timely research, and we introduce the HawaiiCoastal Mitigation Guidebook, an indispensable reference for coastalhomeowners and developers alike. This issue is rounded out with afeature on research into behavioral responses to natural disasters byChris Gregg.

Kerry Irish, Assistant Communications Leader

In this issue of Ka Pili Kai...

Tsunami Sense: Understanding Tsunamis andPreparing for the Next Event

ExtensionView: Zoe Norcross-Nuÿu andDolan Eversole

Book Review: Hawaii Coastal HazardMitigation Guidebook

Waiting for the Sirens? Nature is AlreadyGiving You the Signals

Forecast: Improving Warning Systems andEvacuation Maps

Photo Gallery - Beach Erosion in Action

Nä mea like ÿole (Miscellany)

University of Hawaiÿi Sea Grant College Program

On the cover...The eastern shores of Oÿahu likethat of Lanikai Beach aresusceptible to coastal hazardsfrom beach erosion to tsunamis.

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Ka Pili Kai is published quarterly by theUniversity of Hawaiÿi (UH) Sea GrantCollege Program, School of Ocean andEarth Science and Technology (SOEST).UH Sea Grant is a unique partnership ofuniversity, government and industry,focusing on marine research, educationand advisory/extension services.

Director:E. Gordon Grau, Ph.D.

Associate Director:Mary J. Donohue, Ph.D.

Periodicals postage paid at Honolulu, HIPostmaster: Send address changes to:Ka Pili Kai, 2525 Correa Road, HIG 208,Honolulu, HI 96822

(808) 956-7410; fax: (808) 956-3014uhsgcomm@hawaii.eduwww.soest.hawaii.edu/SEAGRANT

Acting Communications Leader:Mary J. Donohue, Ph.D.Assistant Communications Leader:Kerry IrishInformation Technology Specialist:N. Harold Richman, III, Ph.D.

Web and Multimedia: Ed Tamura

Staff Writer: Craig Okumura

The University of Hawaiÿi was designateda Sea Grant College in 1972, following theNational Sea Grant College and ProgramAct of 1966.

Ka Pili Kai is funded by a grant from theNational Oceanic and AtmosphericAdministration, project M/C-1, sponsoredby the University of Hawai‘i Sea GrantCollege Program/SOEST, under Institu-tional Grant No. NA16RG2254 from theNOAA Office of Sea Grant, Departmentof Commerce. The views expressedherein are those of the authors only.

Ka Pili Kai Editors: Mary J. Donohue,Ph.D. and Kerry IrishLayout and design: Craig Okumura

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~Photo courtesy of the University ofHawaiÿi Coastal Geology Group

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A tsunami scattered fishing boats throughout Kodiak, Alaska, April 1963.~Photo courtesy of the National Oceanic and Atmospheric Administration

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Tsunami SenseTsunami SenseTsunami SenseTsunami SenseTsunami SenseUNDERSTANDING TSUNAMIS ANDPREPARING FOR THE NEXT EVENT

By Edison Gica and Craig OkumuraBy Edison Gica and Craig OkumuraBy Edison Gica and Craig OkumuraBy Edison Gica and Craig OkumuraBy Edison Gica and Craig Okumura

On May 22, 1960 the largest earthquake everrecorded occurred on the Chilean coast ofSouth America. The earthquake and

resulting tsunami took more than 2000 lives inChile then traveled across the Pacific Ocean, taking61 lives in Hawai‘i and 122 more in Japan.Tsunamis can create great destruction and loss oflife within minutes on shores near to their sourceand within hours across an entire ocean basin. Howcan such a wave cause so much damage?

Tsunamis, meaning harbor waves in Japanese, arefrequently misunderstood events of nature. Oftenincorrectly referred to as ‘tidal waves’, tsunamishave no connection to the rise and fall of earth’stides – in fact, they are caused by large-scale oceandisturbances. Most tsunamis are caused fromearthquakes, though are occasionally caused byother forces such as landslides or submarinevolcanic eruptions. After the initial disturbance ofthe water surface, tsunami waves radiate away in

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A common misconception about a tsunami isthat it is a single wave, when in fact it is aseries of waves that can last for several hours.

all directions, washing over nearby shores andpropagating across large ocean basins (seeexamples in Figures 1 and 2).

A common misconception about a tsunami is that itis a single wave, when in fact it is a series of wavesthat can last for several hours. Usually, the firstwave to reach shore is not the largest and this iswhere unsuspecting curiosity can quickly turn intotragedy when onlookers and survivors of the firstwave begin to inspect the damage too soon.

Wave lengths (the measurement between crests)and wave periods (time between successive wavecrests) of tsunamis are astoundingly different fromcommon wind-generated waves. In comparison,waves produced from the wind have wave lengthsgenerally from60 meters (m)to 150 m andabout a 10-second waveperiod. On theother hand,tsunami waves can have wave lengths of 160kilometers (km) or more with wave periods rangingfrom five minutes to one hour.

Tsunami waves are generally unnoticeable as theymove across the deep ocean until they reach the

shore in their destructive state. As it enters shallowareas, the wave speed slows down, wave lengthshortens and height increases making it veryvisible. A common tell-tale sign that a tsunami willarrive is when near shore waters recedesignificantly, exposing the ocean floor.

Tsunamis can travel quite fast, over 800 km/hourin the deep open ocean and will slow considerablyas they travel over shallower areas. Although speeddecreases as it nears shore, tsunamis still movefaster than a human can run and are strong enoughto pick up boats and debris and carry themhundreds of feet inland, often destroyingeverything on the land in its path (see photo onpage 3).

However, aspowerful anddevastating asa tsunami canbe, not alltsunamis aredestructive.

For example if an earthquake is relatively smalland the nearest coastline far away, a very weaktsunami wave can arrive onshore at only a fewcentimeters high – not big enough to bedistinguished from normal wind generated waves.Also, as the world has seen with Indonesia in

Figure 1. Numerical simulation of the 1946Aleutian tsunami waves propagating through theHawaiian Islands (five hours after theearthquake). ~Courtesy Edison Gica

Figure 2. Numerical simulation of the 1960 Chiletsunami waves propagating through the HawaiianIslands (15 hours after the earthquake).~Courtesy Edison Gica

Hawaiian Islands

Hawaiian IslandsAlaska

Chile

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recent months, destructive tsunamis are not alwaysthe inevitable conclusion to a major earthquake.The earthquake on March 28, 2005 measuring 8.7on the Richter scale, did not produce a destructiveocean wide tsunami compared to the similarlyregistered 8.5 earthquake on December 26, 2004 inthe same region generating a tsunami reachingnearly all countries bordering the Indian Ocean.

Hawaiÿi has had its share of tsunamiencounters. On November 29, 1975 anearthquake was generated in Kalapana onthe southern coast of the island of Hawaiÿi.Neighboring Keauhou Landingexperienced a local tsunami (1,000 km orless from the source); waves were reportedas high as 14.3 m. Fortunately, the otherHawaiian islands were unaffected withreported wave heights were less than 0.5 m.

Besides being susceptible to local tsunamis,the geographic location of the HawaiianIslands should make residents vigilant tothe potential of distant tsunamis(earthquake 1,000 km or more fromHawaiÿi). The Pacific Rim, an area withfrequent and often significant earthquakes,could produce a tsunami that would affectHawai‘i (see Figures 1 and 2).

Two of the most destructive tsunamisoriginating in the Pacific Rim that have hitthe Hawaiian Islands were caused by the1946 Aleutian Island and 1960 Chileanearthquakes. A combined death toll of morethan 200 people was recorded in Hilo Bayon the Island of Hawai‘i alone as a result ofboth events. The maximum recorded waveheights at Hilo Bay of each tsunami were8.1 m in 1946 and 10.7 m in 1960.

While impossible to predict where and whenearthquakes that could cause a tsunami will occur,we do understand that Hawai‘i is vulnerable. ThePacific Tsunami Warning Center in Ewa Beach,O‘ahu attempts to mitigate potential harm of atsunami by closely monitoring earthquakes in thePacific region. This is done in part by using aspecial buoy called DART – or Deep-oceanAssessment and Reporting of Tsunamis (Figure 3)developed by the National Oceanic andAtmospheric Administration’s Pacific MarineEnvironmental Laboratory (NOAA/PMEL). There

are six DART buoys deployed in the Pacific Oceanwhich help to provide real time information for thewarning center. Once a determination has beenmade if an earthquake is of concern and there is areal possibility of a tsunami, Civil Defenseagencies will implement evacuation procedures.

This warning system is just as useful to determineif there is no threat of a tsunami. In November2003 a tsunami was generated off the AleutianIslands, Alaska, but was considered a “no threat”event for Hawai‘i preventing unnecessary concernand unneeded evacuations on the islands.

The accuracy of these warnings are critical to theState of Hawaiÿi as any underestimation may causeserious consequences in future events, such asinjuries and fatalities, loss of credibility of the civildefense agencies and the loss of tourism revenue.The University of Hawaiÿi Sea Grant CollegeProgram and the Joint Institute for Marine and

Figure 3. Deep-ocean Assessment and Reporting of Tsunamis(DART) Buoy setup. ~Illustration courtesy NOAA/PMEL

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Check your local telephonedirectory to learn abouttsunami evacuation maps.

How do I prepare for a tsunami?Know your facts:

1. Local tsunamis occur within minutes of a nearby earthquake, landslide orother near shore disturbance. Emergency and civil defense authoritiesmay not have enough time to warn the public. If you feel the groundshake and you are near the shore, move to higher ground immediately.

2. Distant tsunamis are detectable and local emergency and civil defenseauthorities will warn the public through sirens and radio and televisionbroadcasts. A civil defense siren means you should turn on the radio ortelevision as it may be a tsunami warning. Refer to your local telephonedirectory white pages for tsunami evacuation maps.

3. An approaching tsunami often causes near shore waters to quickly retreatsignificantly exposing reefs and the ocean floor. Upon landfall, tsunamismove faster than humans can run, so get to higher ground or move tohigher floors in a concrete building. If you already see a tsunami waveapproaching, you have very little time to act.

4. Tsunami waves arrive in a series and can last for hours. One tsunamiwave does not mean it is all clear. Once you get to higher ground and awave passes, remain there or move higher as more waves are likely tofollow. Keep in mind: the first wave is not usually the strongest.

Atmospheric Research (JIMAR) recognized this in1999 and responded by co-funding tsunamiresearch of investigators Dr. Michelle Teng of theDepartment of Civil and EnvironmentalEngineering and Dr. Kwok Fai Cheung of theDepartment of Ocean and Resources Engineering.Their research improves prediction models fortsunami run-up (sea-surface height increase) andcoastal inundation (horizontal distance inland) bydeveloping a two-dimensional run-up modelfactoring in Hawaiÿi’s unique terrain, bathymetryand topography. This model improvescomputational efficiency and its accuracy wasverified with actual field data collected in Hawaiÿiand across the Pacific Ocean. With accurateprediction models, the Pacific Tsunami WarningCenter improves its forecasting abilities and theHawaiÿi State Civil Defense agencies can updatetheir tsunami evacuation maps provided tothe public in local telephone directories.

The Joint Institute for Marine and AtmosphericResearch (JIMAR) is a federally-fundedprogram through the National Oceanic andAtmospheric Administration (NOAA) and islocated at the University of Hawaiÿi at Mänoa.Director of JIMAR, Professor ThomasSchroeder, has been a strong supporter oftsunami research in Hawaiÿi.

Edison Gica holds a Ph.D. in Civil Engineering from the University of Hawai‘i at Mänoaand is a former graduate student of Michelle Teng, Ph.D. of the Department of Civil andEnvironmental Engineering. He is currently a post-doctoral research associate at NOAA/PMEL.Craig Okumura is a staff writer with the University of Hawaiÿi Sea Grant College Program.

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ExtensionViewAt the University of Hawaiÿi Sea Grant College Program (UH Sea Grant),

research and outreach are interconnected. Our scientists study pressing localissues and produce real world answers – then our extension agents translatethat research into useful information for a myriad of audiences. This column

highlights the important work done by our extension agents in your backyard.

When Maui residentsthink of coastalissues, one of theirprimary concerns ischronic shorelineretreat. With anisland-wide sandyshoreline erosion rateaverage of one footper year, erosion hot-spots are widespread,with each requiring unique consideration. UH SeaGrant Coastal Processes Extension Agent ZoeNorcross-Nu‘u provides guidance to Maui Countyin addressing these challenging issues.

Norcross-Nu‘u brings a wealth of experiencestudying shoreline change to her position. She hasboth bachelor’s and master’s degrees from theUniversity of Hawai‘i at Mänoa where shespecialized in coastal geology. For her master’sdegree research, Norcross-Nu‘u studied shorelinechange patterns in Kailua Bay, O‘ahu on both along-term scale (decadal for over 70 years) and ashort-term scale (semi-annually for four years;monthly for one year).

One means of combating shoreline erosion isthrough beach replenishment projects. Sand forreplenishment on Maui is mined from inlanddunes. When the sand is replenished, turbidityplumes are created in the ocean. With concern forpotential impacts of the turbidity on water qualityand marine life brought to her attention, Norcross-Nu‘u put together one of Hawai‘i’s firstcomprehensive studies to examine the impacts of

Zoe Norcross-Nuÿu Dolan Eversole

When theDepartment ofLand and NaturalResources (DLNR)has a questionabout coastaldevelopment orerosion mitigation,they only need towalk down the hallto find a Sea Grant

expert. Dolan Eversole is a coastal geologist andUH Sea Grant Coastal Lands Extension Agent inO‘ahu who serves as a technical advisor to theDLNR on a range of coastal issues.

Eversole is graduate of the University ofHawai‘i at Mänoa (UH Mänoa) where he earnedboth his bachelor’s and master’s degrees ingeology. For his graduate degree, Eversolespecialized in coastal geology working onhistorical shoreline mapping and sedimenttransport numerical modeling in KäÿanapaliBeach, Maui with Dr. Charles Fletcher, a UHMänoa professor. Working directly out of theDLNR Coastal Lands Program office, Eversolebrings a technical background to his work inaddition to many years of practical experienceas an ocean enthusiast and ocean lifeguard.

The mandate of the Coastal Lands Program is tomaintain the delicate balance betweenpreservation and responsible development ofmarine and coastal areas. One major focus ofthe program is initiating and developinginnovative and proactive shoreline management

(Continued on page 8)

How Two Extension Agents Address Coastal Hazards in Hawaiÿi

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beach replenishment. For ninemonths leading up to a beachreplenishment project at Ma‘alaeaon Maui’s south shore, monitoringoccurred on a monthly basis. Duringthe week of sand replacement andfor five days thereafter, monitoringoccurred on a daily basis, followedby two months of intensive followup studies. Monitoring consisted ofwater quality measurements, beachprofile measurements, ghost crabhole and fish counts, benthic habitatvideo transect surveys and sedimenttrap analysis. The study wasdesigned and conducted with theassistance of students from the MauiCommunity College Marine OptionProgram, and was used as a seniorthesis project for one student.

Results from the study indicate thatwithin days after replenishmentturbidity levels declined to belowpre-nourishment levels, suggesting

that perhaps the replenished sandacts as a turbidity suppressant bycovering fine bottom sediments.Additionally, beach profiles showedthat the replenished sand did notmove onto the shallow fringing reefat both ends of the study area;instead, it was mainly dispersedalongshore by currents andtransported offshore into a sand-filled channel at the center of thestudy area. Fish and ghost crabcounts increased following beachreplenishment, and no negativeimpacts other than a temporaryincrease in turbidity were observed.While impacts from beachreplenishment will still be carefullymonitored on a case-by-case basis,the results from this studyhelped to obtain supportfor sand nourishmentprojects from localgovernment agencies.

Norcross-Nuÿu (left) and twoother scientists monitoringwater quality for the Kanai ANalu beach replenishmentproject on Maui. ~Photocourtesy Zoe Norcross-Nuÿu

Eversole videotaping thedrifting patterns of afluorescent-green dye hereleased in the waters ofKühiö Beach, Waikïkï for abeach nourishment project.~Photo courtesy George F.Lee, Honolulu Star Bulletin

techniques compatible with the long-term goal of beach and coastalpreservation.

As a result of both natural andanthropogenic impacts to beaches,many sandy coastlines areexperiencing coastal erosion andbeach loss. To address this, Eversoleand others in the Coastal LandsProgram are working to develop acomprehensive coastal policy for thestate including promoting moreconservative coastal developmentwith greater emphasis on identifyingcoastal hazards and exploringinnovative erosion controltechniques. One project slated forfall 2005 is the restoration ofWaikïkï Beach through a uniqueoffshore sand recycling project. Theplan involves dredging up to 10,000cubic yards of offshore sand toreplenish the Kühiö Beach areawhich has not seen majorrenourishment efforts since 1975.

Norcross-Nuÿu (cont’d)

Eversole (cont’d) One of the innovative aspects tothis project is that it will be usingsand that was once on the beachand has now moved offshore. Thisensures the sand is compatible withexisting sand and is a cost effectivealternative to bringing in new sand.

With the assistance of UH SeaGrant, the DLNR’s Office ofConservation and Coastal Lands hasalso been developing publiceducation programs and distributinginformation and guidelines on thebest management, erosion controldevelopment and constructionpractices for Hawaiÿi’s coastalareas. The goal is to provide thepublic with a broader localunderstanding of coastal processesand erosion alternativeswhich will ideally leadto more informedplanning anddecision-making inthe future.

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A New University of Hawaiÿi Sea Grant PublicationHawaii Coastal Hazard Mitigation Guidebook

About the Author:

based standards for hazardmitigation and then givesrecommendations forimplementation that minimizeburden to the regulatedcommunity. The thrust of theguidebook is on implementing themeasures through guidance,industry standards, policy and theuse of existing regulations.

Topics covered in the guidebookinclude coastal and bluff erosion,flooding, wave inundation,hurricanes and tsunamis. Since thedangers for each of these hazardsoverlap, four hazard zones areidentified that take into accounthow these hazards might act inparticular regions.

The guidebook is a useful tool foranyone interested in reducing riskfrom natural hazards. It was madepossible with grants from theHawai‘i Department of Land andNatural Resources, Office ofPlanning - Coastal ZoneManagement Program, Universityof Hawai‘i Sea Grant CollegeProgram, and the National Oceanicand Atmospheric Administration’sPacific Services Center and CoastalServices Center.

As a coastal homeowner, have youever wondered where to gettechnical, yet easy to understandinformation about minimizingerosion concerns on yourproperty? Or as a contractor, haveyou thought about how vulnerableyour building is to a hurricane? Ifyou have, then the new book byDennis J. Hwang, Hawaii CoastalHazard Mitigation Guidebook, is amust read. At 242 pages with 13summary tables and 80 colorfigures displaying thegeographical variability of hazardrisk in Hawai‘i, the guidebook isan informative, technical resource.

Designed for a wide and variedaudience from planners andarchitects to homeowners andgovernment agencies, theguidebook complements theFederal Emergency ManagementAgency’s Coastal ConstructionManual with a special emphasis onland use planning and siting. Theguidebook is a resource to reducethe risk to coastal development byplanning for natural hazards suchas erosion, flooding, tsunamis andhurricanes.

Hwang says the guidebookprovides scientific and technically

Copies of the HawaiiCoastal Hazard MitigationGuidebook are nowavailable for $25.00 at:

www.soest.hawaii.edu/SEAGRANTorUniversity of HawaiÿiSea Grant College Program2525 Correa Road, HIG 208Honolulu, HI 96822

NowAvailable

Dennis J. Hwang BS, MS, JD

“We hope that theguidebook can makecoastal developmentstronger and safer,while protecting ournatural resources.”-Dennis J. Hwang

Dennis Hwang has been working in the area of coastal zone management forover twenty years. He has a bachelor of science in geology from the Universityof Rochester, a master of science in geology and geophysics from theUniversity of Hawai‘i and a juris doctorate from the University of Houston.Mr. Hwang is currently with the law office of Reinwald O’Connor & Playdon,LLP and advises government agencies, companies, business and communitygroups in the areas of environmental, land use, and property law.

Book Review

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Waiting for the Sirens?Nature is Already Giving You the Signals

AUniversity of Hawaiÿi (UH) SeaGrant College Program-fundedproject investigating community

resilience to natural hazards in Hawaiÿi hasspawned a multidisciplinary researchproject in Thailand’s disaster zone. TheNational Science Foundation has providedfunding to study factors affectingbehavioral response to tsunami naturalwarning signs using the 2004 IndianOcean earthquake as a case study.

Coastal communities at risk are vulnerableto two tsunami threats with drasticallydifferent warning times from distant andlocal tsunami sources. Threat responsetimes, hours for a distant tsunami butminutes for a local tsunami, confirmdanger to communities may be mitigatedonly if people are trained in two scenarios:official pre-disaster warnings (for distanttsunamis) and real-time sensory andperceptual events produced by animpending disaster (for local tsunamis).This dual training increases the public’s

Reporting of Tsunamis (DART) buoys in thePacific Ocean detect and report tsunamis,but their utility is greatest for distanttsunamis and at best limited for localtsunamis. This is primarily due to limitedtime to effectively communicate warningmessages between scientists, officials andthe public. The DART system is slated forexpansion in the Pacific and to the Atlanticand Caribbean, but reducing tsunami risk inthese areas requires more than a high-techdetection system. Perceptional events suchas ground-shaking and sea level changeshave served as effective warning signalshistorically and may provide the first andonly alert of local tsunami in future events.Communities resilient to tsunami effectsmust be aware of natural tsunami signs andpossess a capacity to respond to bothofficial and natural warnings.

Historic tsunamis illustrate that natural signscan serve as effective warning signals butalso demonstrate that many peopleintentionally enter danger zones. Forexample, survival in a 1993 local tsunami inJapan was high because people recognizedground-shaking as a precursor to imminenttsunami and evacuated immediately by footto higher ground. Survivors did not searchfor friends and family or attempt evacuationby automobile, as did many who perished.Hawaiÿi fatalities have occurred becausewaves often recede before arriving onshore.The exposed sea floor arouses curiosity,drawing people into the danger zone whoare later overcome by waves. Reports of the2004 Indian Ocean tsunami included peopleevacuating upon noticing signs of tsunamisas well as thousands of people going to thebeach to watch incoming waves.

In Thailand, we will collect social data frompeople in affected areas, including thetourist area of Phuket, through interview

Community knowledge of naturalwarnings is needed because mechanicalwarning systems can be rendered ineffective byfactors such as human error and earthquake damage.

capacity to respond effectively to alltsunami threats, but also increases thecomplexity of effective outreach.

Community knowledge of naturalwarnings is needed because mechanicalwarning systems can be renderedineffective by factors such as human errorand earthquake damage. Tsunamidetection and reporting systems such asthe US Deep-ocean Assessment and

A Sea Grant Study Spawns Earthquake/Tsunami Disaster Response Researchin Thailand By Chris E. Gregg, UH Sea Grant Supported Graduate Student

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questionnaires administered by local Thaicollege students. The Thailand survey willbe refined and tested in collaboration withformer UH graduate, Dr. SupinWongbusarakum, director of theInternational Sustainable DevelopmentStudies Institute in Thailand.

Our survey will investigate: 1) awarenessand response to natural warning signs ofthe tsunami, warning provided by others orobservations of their actions, 2) factors thatdetermined which responses therespondents chose, 3) factors respondentsretrospectively believe would haveinfluenced them to act differently and 4)pre- and post-impact tsunami preparedness.We also propose to collect data fromEuropean visitors to the disaster area whohave since been repatriated.

Our Thailand study will be the firstsystematic study of human sensory ofevents surrounding tsunamis and thusprovide critical insight into the social,cognitive, cultural, environmental, andpolitical factors that influence sensory andbehavioral response. The study isgrounded in theoretically rigorousbehavioral models drawn from the health-protection literature and from memorytheory. This exploratory research willstrengthen existing models and bridge thegap between what is known aboutbehavioral response to official versusnatural warnings. The findings are criticalgiven an effective overall tsunami warningsystem must reflect social dynamics aroundboth types of warnings.

Another aspect of our research relates tomemory theory. Some memory researchsuggests recall of major life events of thosewith direct disaster experience is extremelyaccurate at six months and remainsaccurate for years. Thailand resident datawill be collected by the end of April andEuropean Visitor data in summer 2005,suggesting high memory accuracy.However, we will validate the accuracy ofsurvey responses through question designtechniques, inter-respondent comparisonsand comparisons with physical data

collected on ground shaking intensity andtsunami behavior. We will also return toThailand in 2006 and resurvey respondentsto test the accuracy of memory recall. Thislongitudinal study component will allow usto gain new knowledge about traumaticevent memory and will provide the firstlongitudinal sensory and response data fortsunamis.

Remember, when you feel the ground shakeand are in a coastal area play it safe and leaveimmediately for higher ground.

With my advisor, UH Professor BruceHoughton, we have assembled amultinational research team includingThailand social scientist Dr.Wongbusarakum, Australian psychologistProfessor Douglas Paton, New Zealandphysical and social scientist Dr. DavidJohnston, and psychologists Professor R.Lachman and Dr. Janet Lachman.

An effective warning system for reducingdistant and local tsunami risk mustintegrate technical and natural subsystems.Awareness of both subsystems and theconstraints each imposes on availableresponse time is critical. People must alsobe able to recognize when they are in asafe versus a dangerous place. Finally,recognition of warning signs must motivatedesired actions. For local tsunami, this isimmediate evacuation to higher ground.For distant tsunamis, this is listening andresponding as requested by Civil Defensethrough media such as radio or television.Remember, when you feel the groundshake and are in a coastal area play it safeand leave immediately for higher ground.Occasionally there will be “false” alarms;live to tell about them! If you see the oceanrecede or rise at unusual rates or to unusuallevels, evacuate to higher groundimmediately. Also note that the Hawaiÿisiren sounding is an Attention/Alert signalthat means, “Tune to a radio or televisionfor information.”

Chris E. Gregg hasrecently completed hisPh.D. at the Universityof Hawaiÿi in theDepartment of Geologyand Geophysics.

Ka Pili Kai

By Yong Wei, UH Sea GrantSupported Graduate Student

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Tsunami Warning Technology

Established in 1949, the PacificTsunami Warning Center(PTWC) in Hawaiÿi monitorsdata from water-level stationsthroughout the Pacific fordisturbances associated withtsunamis. When an earthquakeoccurs, the PTWC staff comparewater-level data near theearthquake source to data frompast tsunamis – both real andcomputer modeled events. Notall large earthquakes producetsunamis, so these measurementsare studied to determine if atsunami has been generated anda warning should be issued.

Since 2003, the University ofHawai‘i Sea Grant College

Program has been fundingresearch in the Department ofOcean and ResourcesEngineering to develop atsunami forecast model that willincrease the accuracy of thecurrent warning system. Theinverse algorithm model wedeveloped, which uses therecorded tsunami signals at thewater-level stations to infer theseismic source, is extended topredict the tsunami waveformsat strategic locations nearHawaiÿi. We participated in theimplementation of this model atthe National Oceanic andAtmospheric Administration’sPacific Marine EnvironmentalLaboratory (NOAA/PMEL)which will improve the tsunamiforecasting capability for thePTWC and the West Coast andAlaska Tsunami WarningCenter. This model is expectedto provide these centers with auseful tool to predict theseverity of a tsunami in progressand to better advise civil defenseagencies for emergencymanagement.

Updating Hawaiÿi’s EvacuationMaps

After devastating losses from the1946 and 1960 tsunamis,Hawai‘i built a statewidetsunami emergency responsesystem. The system includesunified state and countyemergency plans, evacuationmaps that are published intelephone books, a coordinated

statewide siren system tied intoan emergency alert system, andfrontline emergency personnel.

Hawaiÿi’s current evacuationmaps were developed in 1991based on relatively simple one-dimensional models, meaningthey do not account for theeffects of ocean-floortopography that can alter thebehavior of a wave as itapproaches the shore. Theseearly models need to be updatedto account for additionalvariables that can now bemeasured. When a tsunami hitsthe coast of Hawai‘i, the impactand potential damage will varydepending on where you are.For example, in the 1946 and1960 tsunamis, Hilo Bay wasseverely affected, yet othernearby areas did not fare asbadly. This was due in largemeasure to the shape of theocean floor in Hilo Bay, whichamplified the power of thetsunami.

We have been involved with amulti-agency effort known as theHawaiÿi Tsunami MappingProject. Initiated in 2003, thefocus of this project has been toupdate the current evacuationmaps using the most advancedtwo-dimensional modelsavailable. Thus far we havecompleted the necessary modelsand are now using them toupdate the evacuation maps forHawaiÿi.

Is Hawai‘i prepared for the next tsunami?

Researchers at theUniversity of Hawaiÿiare working to answerthis question in theaffirmative by usinginnovative modelingtechniques to improvetsunami warningsystems and updatestate evacuation maps.

Improving Warning Systems and Evacuation Maps

Forecast

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Yong Wei is a graduate studentat the University of Hawai‘i inthe Department of Ocean andResources Engineering. HisPh.D. research isfocused onpredicting potentialtsunami impacts onHawai‘i.

At a Glance...A computer simulation of theIndian Ocean Tsunami

~Courtesy Yong Wei.

This new model takes intoaccount historical data from theprevious six tsunamis to hitHawai‘i and creates acomprehensive view of areaslikely to be affected in the nextevent. In the mapping projectHawai‘i’s 800-mile coastline isbroken down into 28 individualsegments. For the past year, theeffort has focused on O‘ahu’sNorth Shore. The evacuationmaps are based on the computedinundation limits, recognizedlandmarks, and developmentpatterns. As a result of this newmodel and study, it has beendetermined that the evacuationline for some locations on theNorth Shore must be extendedfurther inland.

Updated evacuation maps forthe North Shore were recentlycompleted and will appear in thenext printing of the public phonebook. Studies for the next area,East Honolulu, will begin in July2005 and are expected to becompleted by early 2006.Current efforts only allow fortwo to three areas of Oÿahu to bestudied each year. The majordifficulties in creating thesemaps lies in the availability andcalibration of the topography forcoastal areas in Hawai‘i, whichplays an important role intsunami modeling. The entireproject is expected to takeseveral years to complete.

Ka Pili Kai14

Hawaiÿi’s developed coastlines can suffer if long-term shoreline erosion is not accommodated. Sandybeaches statewide erode at an average of one foot per year. ~Courtesy Zoe Norcross-Nuÿu

Photo GalleryBeach Erosion in Action

Beaches are fundamentally important toHawaiÿi’s visitor industry, the daily qualityof life of residents, and as a component of

the marine nearshore environment. Over the pastcentury and a half, coastal development trendshave interfered with natural changes in beachposition threatening private property and buildingswith coastal erosion. To improve management ofbeaches and other littoral sand-dependent

environments, it is important to enhanceunderstanding of sand budgets and their dynamicnature.

The University of Hawaiÿi Sea Grant CollegeProgram (UH Sea Grant) continues to fund theresearch of Dr. Charles Fletcher of the Departmentof Geology and Geophysics at the University ofHawaiÿi at Mänoa. Fletcher leads the Coastal

Ka Pili Kai 15

A fully-recovered beach surrounding a pavilion in Käÿanapali, Maui. With seasonal erosion, sand washesaway and returns to the same area during opposite times of the year. ~Courtesy Dolan Eversole

Geology Group, an affiliation of researchers,technicians, and graduate students who exploreshoreline change, carbonate geology, reef geology,sedimentology and coastal morphodynamics inHawaiÿi. Photos are courtesy of Dolan Eversoleand Zoe Norcross-Nuÿu, former graduate studentsof Fletcher’s and current colleagues as UH SeaGrant Extension Agents. (See pages 7 and 8 onEversole and Norcross-Nuÿu).

A current project of the Coastal Geology Group isan analysis of historical shoreline trends on Oÿahuand Maui. This work will help to better planand manage development by providingscientific information on the rate andscope of shoreline movement. Formore details on this and other workby the Coastal Geology Group goto www.soest.hawaii.edu/coasts.

Ka Pili Kai

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University of Hawai‘iSea Grant College Program2525 Correa Road, HIG 210Honolulu, HI 96822

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RecycledPaper

Ka Pili Kai is printed on recycled paperwith soy based inks

16

Hanauma Bay Education ProgramCalendar of Events for May 2005:

June 2: “2004 East Oÿahu Findings” by DaveRaney, Reef Check Hawaiÿi.

June 9: “Special Ocean Day Event” sponsored bythe Northwestern Hawaiian Islands Coral ReefEcosystem Reserve. Program and speaker to beannounced.

June 16: “Coral Seas” a Blue Planet film producedby the British Broadcasting Corporation.Introduced by Cindy Hunter of the Hawaiÿi CoralReef Initiative and the Hawaiÿi Institute of MarineBiology.

All events are held Thursday evenings in theHanauma Bay theater and are approximately onehour. Events are free and open to the public.Parking and entrance to the Bay are free after 4:30pm and park hours will be extended toaccommodate special events listed. No reservationsare required. For more information, or to sign upfor event announcements via e-mail, contact theHanauma Bay Education Program at (808) 397-5840 or hanauma@hawaii.edu.

Coming Spring 2005...A University of Hawaiÿi Sea Grant Publication

“Purchasing Coastal Property in Hawaiÿi:A Practical Guide of Common Questions and

Answers”

This booklet provides answers to practicalquestions such as:

• What to do if your oceanfront property isthreatened by erosion

• What types of building features helpreduce or prevent storm damage

• What are common signs of coastal hazardproblems

• Can you get insurance for floodingdamage

If you are interested in obtaining a copy, please callthe University of Hawaiÿi Sea GrantCommunications Unit at (808) 956-7410 or e-mailuhsgcomm@hawaii.edu

Sponsored by the Hawaiÿi Coastal ZoneManagement and the Hawaiÿi Department of Landand Natural Resources

Read Ka Pili Kai online at: www.soest.hawaii.edu/SEAGRANT/communication/kapilikai/kapilikai.html