ೋ෨ࢥ‫ݪࡄڠ‬༭࣬ల 32 ࣢Ȫ2015ȫȟ Research Report of Tsunami Engineering Vol.32Ȫ2015ȫ33 ȡ 45

33ŐŧŧŴũŰųŦġŦŷŢŤŶŢŵŪŰůġŰŧġŧŪŴũŪůŨġţŰŢŵŴ
ĮġōŦŴŴŰůŴġŧųŰŮġŵũŦġĳıĲĲġňųŦŢŵġņŢŴŵġŋŢűŢůġŵŴŶůŢŮŪġŢůťġŪŵŴġŧŶŵŶųŦġŤũŢŭŭŦůŨŦĮ

Anawat Suppasri1, David Nguyen, Yoshi Abe, Mari Yasuda,
Yo Fukutani, Fumihiko Imamura and Nobuo ShutołţŴŵųŢŤŵ

arrival. Correctly understanding topographic
conditions of each fishing ports and revising

Offshore evacuation, a behavior by thefishermen to save their boats from incoming

guidelines with explicit procedures are therefore
indispensible.

tsunami, has gained more attention in the wakeof the 2011 Great East Japan Earthquake (GEJE).
This tradition had been practiced in tsunamiĲįġ ŐŧŧŴũŰųŦġ ŦŷŢŤŶŢŵŪŰůġ Ţůťġ ųŦŴŦŢųŤũġ
ŰţūŦŤŵŪŷŦŴġ

prone fishermen communities, including thosealong Sanriku Coast in Northern Tohoku. By

1.1 Offshore evacuation by the ¿shermenboats heading offshore prior to the tsunami’s

Fishing boats are the single most importantarrival, the boats are considered to be saved withasset for fishermen as their livelihoods depend

smaller tsunami size in the deeper ocean. With

entirely on their ability to operate from a boat

many ¿shermen practicing this evacuation during(Suppasri et al., 2013). Previous study foundthe GEJE, this effort has been regained attention

that damage probability of fishing boats wasfor protecting ¿shermen’s crucial asset, the boat,

significantly increased when the tsunami heightand various guidelines and maps to evacuate

was more than 2 m or when the Àow velocity was

offshore have developed and revised across Japan

more than 1 m/s (Suppasri, et al., 2014). In times

since then. Relevant evacuation procedure is alsoof tsunami, extreme anxiousness on their boats

considered and practiced in the US, revealing

make many ¿shermen go to the coast to con¿rm

the importance of this procedure beyond

its condition or strengthen mooring before

Japan. Nevertheless, detailed study on offshore

evacuating to higher ground. Some ¿shermen evenevacuation to understand its most appropriate

decide heading to the ocean with their boat. This

procedure for a survival has been limited.

is called “Oki-Dashi” or “Offshore evacuation”, aThis paper summarize the results of indepth

Japanese tradition that has been practiced amonginterviews on fishermen’s evacuation response

fishermen to protect their boats from tsunami.

during the GEJE, and explains its relationship to

Fishermen can save their boats by going offshore

geography con¿rmed on site. The result suggests

rather than leaving them moored at ¿shing ports,that ¿shermen experienced tsunami in rias coast

because tsunami size decreases with sea depth.

had better chance of evacuating boats offshore

However, this action could be life threatening

while those in coastal plains or inner bay had not.

and needs a well experience for a right decisionThis was due the decision of ¿shermen on theirwhether to evacuate into the ocean or toproximity to the coast against time of tsunami’s

higher ground. Even if decided for an offshore
evacuation, the boats need to be wellcontrolled,

1

International Research Institute of Disaster Scienceand encounters many additional dif¿culties while(IRIDeS), Tohoku University.

evacuating in the ocean. This type of evacuation,ೋ෨ࢥ‫ݪࡄڠ‬༭࣬ల 32 ࣢Ȫ2015ȫ

34

Fig. 1 Evacuation Àow chart of ¿shermen during an earthquake and tsunami
therefore, was not of¿cially recommended by theinÀuencing the amount of time needed. If seawalls

national government prior to the GEJE and theare too high, they will affect the landscape of theguideline has since been revised.

ports and residences will have more difficultyin observing the initial tsunami wave condition

Theoretically, four types of fishermen’s
behavior can be observed after an earthquake:

before it’s arrival. Moving residential areas tohigh ground will help to save lives and reduce
housing damage in the long term but it will cause

A: Fishermen feel an earthquake inland andevacuate to a higher ground
B: Fishermen feel an earthquake inland anddifficulty for fishermen especially in terms ofaccess to aquacultural work, requiring more timereaching their boats to go offshore.

evacuate offshore with their boats
C: Fishermen feel an earthquake offshore and

1.2 Research Objectives

return inland to evacuate higher ground

This study explores the decisions of ¿shermen

D: Fishermen feel an earthquake offshore and go

regarding the offshore evacuation and its

to the deeper sea with their boats

corresponse results in the wake of the 2011

For type A, ¿shermen “inland” includes those

GEJE. Questions are addressed along the offshore

who feel an earthquake at home and leave toevacuation procedure, including: i) how decisions

strenthen boat’s mooring prior to evacuating

on evacuation, to higher grounds or offshore, arehigher ground.

made; ii) how far did boats evacuated offshore;and iii) what are the problems encontered in the

According to the Kahoku Shinpo (2013a), at

ocean during the evacuation. Newly developed

least 1,100 boats evacuated offshore and at least

activities after the 2011 tsunami in other regions

26 had failed. The primary reason for the failure

weree also introduced to demonstrate present

was said to be the shortage of time, compared toattempts to mitigate problems related to offshore

the needed time for the access to port from inland,evacuation. By doing so, futher recommendation

evacuate to the deepest part of the bay, and tofor research practice in the area, such as ¿shingfurther sail into the open ocean. In some cases,

port management, can be developed. The resultsboats can catch a ¿re from Àoating debris.

of this study can be an input for the ¿shermen’s
evacution procedure for the future tusnamis as

The tsunami generated from the 2011 Great

well as general problems occuring during theEast Japan Earthquake destroyed multiple ports inreconstruction of fishing ports. This is because

the Tohoku Region. The reconstruction of ¿shing

it is important not only to save lives during aports depend on a variety of factors such as thetsunami event, but also to prepare for a period ofheight of new seawalls and residential areas,

hardship that may follow after the disaster.

Offshore evacuation of ¿shing boats
 Lessons from the 2011 Great East Japan tsunami and its future challengeĳįġŐŧŧŴũŰųŦġŦŷŢŤŶŢŵŪŰů

35

on specific earthquake magnitude and tsunami
arrival time. However, this suggestion is not

Offshore evacuation has never been officially

officially recommended by the government asrecommended as an emergency response

driving a boat towards a tsunami is considered

procedure for the fishing ports by the national

too dangerous and complicated. Boat operating

government. Although such practice has aexperiences and even a bit of luck can inÀuence

great potential to save the boats, but risk losing

the outcome of a deep sea evacuation process.

¿shermen’s lives without a technique and a rightThose who fail to do this will not only lose theirtiming decision. Nevertheless, this evacuationboats but risk losing their lives.

has been commonly performed by the ¿shermen

Scientific researches related to safe offshore

in areas experiencing frequent tsunami, and moreevacuation are limited, but minimally available.

attention are being paid after the 2011 GEJE. This

Ohashi et al. (2007) used a tsunami numericaltype of evacuation is also regulated in the coastal

simulation to create an offshore hazard map as

areas of the US, which explains the importance

supporting tool for offshore evacuation of ¿shingof further attention. Coastal states affected by theboat in Kesennuma city. The hazard map wastsunami from the GEJE has also begun to revise

created by basing the questionnaire survey results

their rules based on their experience. However,asking the time for preparation and evacuation for

scientific research on this topic is minimallyall possible scenarios, similar to the Fig. 1.

available.

Torii et al. (2010), inspired by the great loss ofthe 2004 Indian Ocean tsunami, has been working

2.1 Japanese experience and its transformation

on a development of a tsunami early alert and2.1.1 Response against major earthquake events

evacuation support system for fishing boats.

before the 2011 tsunami

They examined a possibility of using the Area

Developed from generations of experience,

Mail service as an application to the smart phone

retreating offshore is a common practice foras support system for the offshore evacuation.

Japanese ¿shermen to reduce the risk of damage

During the drill in Iwate prefecture, they asked

from tsunamis. As the height of tsunamis are

small boat using the Area Mail service to return

generally smaller in the deep sea (50 meters orback to the port and medium boat to evacuate todeeper), boats will be safer than simply mooring

100 m deep sea. Both boat types spent 67 min to

their boat at port. Thus, instead of evacuating toreach their target points.

higher ground, fishermen will attempt to move

Prior to this study, Katada et al (2012)

their boat to the deep sea as soon as possible afterinvestigated the offshore evacuation using ¿shing

the event of a large earthquake. An example canboat against the 2011 tsunami. They examined

be seen from a legend originating in Enoshima

offshore evacuation behavior of fishermen in

Island’s Onagawa Town. The legend states that

Nemuro city, Hokkaido using a questionnaire toboats will be safe if they are located in a sea

approximately 200 fishermen as reconsideration

where its depth is three times the expected heightof future evacuation plan. They found that amongof an incoming tsunami (Hodaka, 2012).

half of fishermen evacuated offshore before theJapan’s Fisheries Agency (2006) mentioned

estimated tsunami arrival time, only onethird ofin their guideline that boats should be at 50

them could reach the safe zone (50 m sea depth)

meters or deeper in the case of a major tsunami.

and onefourth of them returned back to the port

The guideline provides information on which

after the major tsunami warning were cancelled.

minimum sea depth boats should go to are based

36ೋ෨ࢥ‫ݪࡄڠ‬༭࣬ల 32 ࣢Ȫ2015ȫ

2.1.2 Responses against major earthquake events

2011 tsunami. Consequently, most of fishermen

after the 2011 tsunami

decided not to evacuate offshore due to lessons

Since the 2011 tsunami there were three

from the 2011 tsunami, however those who didearthquakes that generated tsunami advisoryevacuate offshore might have thought that they

warning in Miyagi Prefecture:would be fine because of the different tsunami
size.

7/12/2012 MiyagiOki (M7.3): A tsunami
warning was issued in Miyagi Prefecture

2.1.3 Rules for offshore tsunami evacuation andand a tsunami advisory was issued in mostthe drill after the 2011 tsunami

prefectures along the east coast of Japan. A

Tohoku Region

maximum tsunami of 1.0 meter (JMA, 2012) was

Aomori Prefecture proposed rules for offshore

observed in Ayukawa but no major damage was

evacuation: 1) In the case of a 5 meter tsunami

reported (Kahoku Newspaper, 2012). However,warning, the required sea depth and evacuationa fisherman in the north of Iwate Prefecture

time is 50 meters and 40 min respectively and(observed tsunami height was only 0.20 m)

2) The required sea depth in case of a 10 meter

who was evacuating offshore 10 min after thetsunami warning is 150 meters in sea depth.

earthquake, went missing. Japanese Coast Guard

However as at least 60 minutes is required toreported that his boat was found on the sameevacuate, leading the prefecture to consider deepnight and his body six days later (Mainichisea evacuations as too risky (NHK News, 2014).

Newspaper, 2012).

In addition, at night, offshore evacuation is not

26/10/2013 FukushimaOki (M7.1): At tsunami

allowed for boats that have no lights as they

advisory was issued in Iwate, Miyagi andcannot see the tsunami height. In local fishery

Fukushima prefectures resulting the maximum

cooperation in Aomori Prefecture, they decided

tsunami height of 0.200.30 meter (JMA, 2013).

two rules for no evacuations offshore” 1) in case

There was no damage or report about offshore

tsunami arrive earlier than 100 minutes and 2)

evacuations but movement towards the sea

in the case of a tsunami warning (ABA News,

could be observed during a live broadcast by the2014).

authors.

In 2013, Sekinehama village, in Mutsu city

1/4/2014 Chile (M8.2): Tsunami advisory wasof Aomori Prefecture, organized an offshore

issued along the east coast of Japan 18 hours

evacuation drill for fishing boats. The tsunami

after the great earthquake in the north of Chile.

scenario was 5 meters which arrived within 30

Maximum tsunami height of 0.60 m and 0.20

min. Fishermen were advised to reach their target

0.30 m in average were observed (JMA, 2014)

distance for evacuation, which was about 4 km

but no damage was reported in Japan (Kahoku

offshore. In fact, the drill was conducted a few

Shinpo Newspaper, 2014). In Aomori prefecture,

hours after the magnitude 7.1 Fukushimaken

there were some fishermen that evacuated

Oki earthquake mentioned previously. Althoughoffshore (47 News, 2014) but some decided notthey could leave the port within 12 minutes, due

to do because of strong wave current during theto the 10 m/s strong winds, they spent 2235 mintsunami advisory period (ABA News, 2014).

to reach the target evacuation area which was
longer than the expected of 1520 min (Kahoku

In brief, observed tsunami heights from thesethree nearfield and farfield tsunami eventswere miniscule (1 m or less) compared to the

Shimpo News, 2013b).

Offshore evacuation of ¿shing boats
 Lessons from the 2011 Great East Japan tsunami and its future challenge
Hokkaido Region

37

that caused significant damages four years after

In preparation of the evacuation of fishing

the event in 2011. Most fishermen prefer not toboats, drills are performed every year since 2012

evacuate offshore because of the last experiencein Toyokoro Town in the Nakagawa district andbut some of them still prefer to evacuate after

Urahoro town in the Tokachi district of Hokkaido

understanding that other tsunamis were not as(Tokachi Mainichi Newspaper, 2012 and 2013).

large or comparable to the 2011 tsunami. For

Every year, about 2030 boats attended the drill

those ¿shermen who are still willing to evacuate

which had an objective to evacuate the boats tooffshore, they should keep in mind that tsunami

a sea that was 20 meters in sea depth rand about

sizes can still be large even if the earthquake

3 km from the port. They found that the boats

magnitude is small, likewise a tsunami might

took about 1520 min to the specified point. In

can also be larger than the 2011 event if anaddition, it took 1020 min from the port to a safe

earthquake of a similar magnitude were to again

high ground by walking. Even ¿shermen in theseoccur. Hence, local governments in many regions

two areas know the required time for evacuating

all around the country have placed considerable

offshore but if the great earthquake had occurred,effort in improving countermeasures that support

they still have difficulty in deciding whether tooffshore evacuation. such as criteria if the

spend 1520 min to save their boats offshore or

offshore evacuation can be allowed, revising the1020 to run to high ground.

required sea depth for each expected tsunami
height, offshore evacuation drill and revising

Shikoku Region

or creating new offshore evacuation map using

Tokushima Prefecture is an example of a region

numerical simulation and advanced informationthat affected by the 2011 tsunami that was 1

technology. Using the actual ¿shing boat damage

meter or larger in height. During that time, aboutdata in case of the 2011 tsunami might be able to25 ¿shing boats evacuated offshore to an area 25

help considering the suitable sea depth rather thanmeters of sea depth. All 25 boats were reported

only using theoretical analysis of the damage.

to be safe (NHK, 2014). However, a tsunami

Fishermen seem having higher awarenessgreater than 10 meters which could arrive withinand cooperating to disasterrelated activities

10 minutes is expected in this region (Cabinet

organized by the local governments. Nevertheless,of¿ce, 2012). Several ¿shery cooperatives in thisthe challenge is how to remain this high level ofprefecture decided that for such a large tsunami,

awareness so that offshore evacuation drill andthe target sea depth is not 25 meters but at least

other activities will keep continuing until the next

50 meters. They prepared offshore evacuation

great event. Lessons and activities in Tohoku

maps showing evacuation needed areas against

region should be more actively applied to the west

specific estimated tsunami height. For example,of Japan against the Nankai trough tsunami which

at least 70 meters for tsunami with the height oflarge tsunami might reach coastal communities

4 meters and 110 meters for a 6 meter tsunami

within 510 min after the earthquake.

(NHK, 2014).
2.2 Beyond Japan
2.1.4 Adaptation after the 2011 tsunami

2.2.1 Experience in the US

Evacuation responses to other tsunami

While Japan experienced the brunt of thewarnings and disaster countermeasures related totsunami, damages caused by waves were recorded

activities after the 2011 tsunami are introduced

as far west as Hawaii and California in the United

in the previous sections. There were no tsunamis

States. In Oregon, tsunami surges hit Brookings38ೋ෨ࢥ‫ݪࡄڠ‬༭࣬ల 32 ࣢Ȫ2015ȫ

Harbor and entered both the basin for sporting

had urged vessels to leave their harbors and notvessels and the basin for commercial vessels.

to return until an all clear sign was given (CBS

Ships that were tied to the ports were damaged2012).

and sea walls collapsed. The damage was

The State of Hawaii’s Department of Land

ampli¿ed by blockage of the Chetco River which

and Natural Resource’s Division of Boating andshares a common drainage with the harbor. As

Ocean Recreation (DOBOR), advises owners

river water was running high with winter runoff,

to take their boat on a trailer and leave thethe surge had nowhere to go but into the two

evacuation zone. In the event that it cannot bebasins. According to Curry County, ten to twelve

trailered, the manual suggests operators to moveboats were missing or destroyed and 60 percent

the vessel offshore to waters 300+ feet in depthof the docks were damaged (Manning, 2011)

as soon as a tsunami warning is declared, andThe State of Oregon provides a tsunami

to maintain adequate supplies of food, water,awareness manual for boaters and fishermen

fuel as well as ensuring the ability to receive

developed by NOAA, Sea Grant Oregon, andcommunication on harbor conditions. Boats

Oregon State University. The procedures for boat

should not return to harbor unless an of¿cial “Allowners vary depending whether the tsunami wasClear” announcement has been made for a given

generated from a distant earthquake or a local

harbor. In the case of a local earthquake, likeone. In the case of a distant earthquake such as

Oregon, DOBOR suggests immediate evacuation

the 2011 Great East Japan Earthquake, the manual

to higher ground or vertically beyond the fourthsuggests boat operators to judge how much time

floor in the nearest reinforced concrete building

has passed from the tsunami and for those out inwith four or more Àoors.

sea to head to an area where the water is 90 m
or deeper and to follow the radio. Those whose

2.2.2 Differences between the Japanese and US

boats are still in port are advised to either movescenarios

their boat and anchor upriver, cross the bar andA s t h e G r e a t E a s t J a p a n Ts u n a m i w a s

go out to sea, or to moor the boat and evacuate

generated from an earthquake with an epicenter

the inundation zone (Oregon Sea Grant, 2007).

near Sendai, the cities in the Pacific and NorthIn Hawaii, the tsunami surges contributed toAmerica had suf¿cient timing to issue a tsunami$30 USD in damages. 15 boats were sunk whilealert and prepare for incoming waves. Whilehundreds were damaged while moored at port.

coastal cities in the Tohoku Region of JapanThe damages affected multiple harbors across the

had approximately thirty minutes (60 minutes

islands including Keehi Boat Harbor in Honolulu

in the coastal plains) from the ¿rst tremor to thewhich lost over 140 ships, and Maalaea Harborarrival of the ¿rst surge, the tsunami waves wouldin Maui which lost two boats. The US Naval basenot arrive to Hawaii until eight hours after theat Pearl Harbor, located near Keehi Boat Harbor,

earthquake whereas California and Oregon waited

did not evacuate their ships as the small andeleven hours. The Pacific Tsunami Warning

narrow inlet reduces the risk of surges. In 2013,

Center issued a tsunami warning at 07:30 UTC,

based upon the experiences of the 2011 Greator roughly two hours after the earthquake, giving

East Japan Tsunami, the US Coast Guard createdHawaii and the western coast of the US Mainland,safety zones within the commercial harbors

at least six hours to prepare.

of the main Hawaiian Islands that will require

In comparison to Japan, cities in the Unitedevacuation if a tsunami warning is issued. In theStates, including some of those in earthquake

tsunami warnings post2011, the Coast Guard

risk areas such as Hawaii and US West Coast,Offshore evacuation of ¿shing boats
 Lessons from the 2011 Great East Japan tsunami and its future challenge
do not experience the same frequency of39ĴįġœŦŴŦŢųŤũġŎŦŵũŰťŴ

powerful earthquake and tsunami occurrences.
For example, prior to the 2011 Great East JapanThe methodology used by this study includes

Tsunami, the most devastating tsunamis in Hawaii(1) personal interviews with fishermen in theare limited to the 1946 Tsunami that killed 173

prefecture as lessons from the 2011 tsunami

people, primarily in Hilo on Hawaii Island, andand (2) secondary sources, primarily fromanother that occurred in 18134 that is not widely

Japanese news agencies as newly developed

known among locals. The lack of powerfulactivities after the 2011 tsunami in other regions

tsunamis, distance from major earthquake

such as offshore evacuation drills and offshore

occurring regions, and isolation that allows fortsunami evacuation maps. A background of each

ample preparation time, contributes to a reduced¿shing port is provided to con¿rm ¿eld surveys

sense of urgency in comparison to their Japanese

conducted during the interview. We mainly

counterparts. Indeed, in both Hawaii and in thefocused on the fishermen that experienced the

US West Coast, spectators arrived to areas under2011 tsunami and continues to rely on fishingwarning in order to witness the event.

as done for generations. Our interviews with the

The lack of this sense of urgency in Oahu,

fishermen spanned approximately eight months,

which did not suffer as much as Hilo in the 1946

covering the Sanriku Ria coast, the Sendai Plains

tsunami, and in the US West Coast, may haveand Matsushima Bay coastal regions in Miyagi

perhaps contributed to the lack of reaction among

prefecture. Details of the surveys including

boat owners to evacuate to the deep sea. As alocation, date, and number of interviewed

response, boat owners were more responsive

fishermen are shown in Table 1. Openended

in subsequent tsunami warnings in Hawaii.

semistructured interviews started by asking if

However concerns over spectators continue tothey evacuated offshore or not. If not, we thenpersist as the recent 2014 Chilean Earthquake led

asked (1) the reason why they did not evacuatedto another tsunami warning, but again, swimmers

offshore, (2) if the disaster dissemination systems

and surfers were spotted, ignoring calls tothat led them to highground evacuation worked

evacuate to safer areas.

properly and (3) which evacuations helter they

Physical factors such as topography andchose. On the other hand, if they evacuatedevacuation zones also influenced the damages

offshore, we then asked (1) the situation duringexperienced by boats in both states. The

the earthquake such as their location and mooring

topography of the inlets also played a signi¿cantmethod, (2) the experiences related to time during

factor in damages as the narrow inlet of Pearlthe earthquake to their evacuation offshore, their

Harbor significantly reduces the risk of tsunami

time spent away from their original location,

surges, while in contrast, Brookings Harbor’s

problems encountered during evacuating offshore,

proximity to river drainage, created additionaland reasons that made led them to return back totsunami risks, leading to a buildup of the surging

the port.

water. In addition, the lack of areas to secure
ships upstream in Oregon, led to the inability ofĵįġŊůŵŦųŷŪŦŸġųŦŴŶŭŵŴ

some ships to escape as there was nowhere todock.

4.1 Response of ¿shermen in Sanriku Ria coast
Kesennuma city: There are some fishermen in
Tadakoshi village who succeeded in evacuating
offshore and very likely to continue to do so inೋ෨ࢥ‫ݪࡄڠ‬༭࣬ల 32 ࣢Ȫ2015ȫ

40

Table 1 Details of ¿shermen interview survey in Miyagi prefecture
Location

Date

No. Interviewed

Kesennuma city, Karakuwa town, Tadakoshi area

20 June 20134

Kesennuma city, Hajikami area

5 April 2013

3

Motoyoshi district, Minamisanriku town, Utatsu,
Niranohama area

6 July 20138

Motoyoshi district, Minamisanriku town,
Shizugawa, Sodehama area

14 September 20132

Ishinomaki city, Yagawahama area

29 June 20134

Miyagi district, Matsushima town

3 November 20131

Shiogama city and

18 May 2013

1

Katsura Island

18 May 2013

1

Sendai city

1 June 2013

1

Fig. 2 Map of the east Japan and Miyagi prefecture displaying depth of the sea

the event of another tsunami. During the 2011

evacuations in the event of future tsunamis. The

tsunami, the fishermen brought food provisions¿shermen attributed their con¿dence to the robustwith them to sea but experienced communication

knowledge and experiences inherited from theirdifficulties as they were unable to retrieveancestors after similar powerful tsunamis affected

information on the situations the condition of

the region in 1896, 1993 and 1960.

their ports and towns. They did not evacuate

In Hajikami, some of the fishermen

offshore for the 2012 tsunami event as theinterviewed also served as volunteer ¿re ¿ghters.

¿shermen resided in a village that differed from

Despite concerns over the safety of their boats,

the location of where their ports were moored.

the fishermen prioritized their duties first. One

The ¿shermen stated that they are not worried andinterviewee went to manually close the seawalls

will continue their current practice of offshore

and another operated a patrol car to evacuate

Offshore evacuation of ¿shing boats
 Lessons from the 2011 Great East Japan tsunami and its future challenge

41

residents. As they were unable to find time tosurvived this tsunami, they may not reconsider

evacuate their boats, their boats were destroyed.

the same deep sea evacuation in a future tsunami

However the interviewees were glad they

event.

survived the tsunami.
MinamiSanriku town: Tsunami awareness

4.2 Response of ¿shermen in Sendai plain coast

may be different even in the same affected area.

regionA fisherman in Utazu, Minamisanriku town

Unlike the Sanriku region, fishermen in thistravelled somewhere inland outside of the village

region need more time (at least one hour) toat the time of the earthquake and did not directly

reach the deep sea. A ¿sherman we met in Sendai

experience the 2011 tsunami, drove his boat

immediately evacuated to high ground as she

offshore during the tsunami warning event on the

believed that she might have no time evacuate

7th December 2012. The tsunami was small but

to the deep sea. However, she stated that one ofthe village expressed disappointment towards his

her friend survived by evacuating offshore nearaction. Thus, even though he resided in a village

Sendai port.

that was devastated by the tsunami, the lack of

All of the interviewed fishermen did not

directly experiencing the tsunami led him to his

evacuate offshore but evacuated to high grounddecision to evacuate while most of villagers still

instead. Especially in areas inside a bay such

remember the awful experience of the 2011 event.

as Matsushima and Shiogama, because the city

In Niranohama, most fishermen immediately

located in the deepest side of the Shiogama bay

evacuated to high ground after strengthening

far from the bay’s entrance, about 3060 min

the mooring ropes to their boats. They said thisis required for fishing boats to evacuate to amight because of tsunami evacuation drill thatdeep sea of at least 50 meters. Although fishing

was organized at the end of 2010 or few months

boats are very important to the respondents,

before the tsunami. Therefore, local residences

most of their boats were relatively small andstill had very high awareness of the tsunami

comparatively cheaper, leading towards lessevacuation. In Sodehama, we met a ¿shing family

incentive to prioritize the safety of their boats

that built their house on high ground tens of years

over their lives. These conditions led ourago. They said this is because their ancestors

respondents in deciding to evacuate to highexperienced the great tsunamis in this region, i.e.

ground. A fisherman told our group that while

1896 and 1933 and they decided to move to thea warning announcement was disseminated via

present location since then.

wireless speakers and vehicle navigation radios,

Ishinomaki city: In Yagawahama, we interviewed

he felt that it was not so successful as it failed toboth fishermen who immediately evacuatedconvince people to start evacuations. In general

to high ground and those who succeeded in

Shigama residents were not as knowledgeable

evacuating offshore. The first group stated thaton tsunami evacuations and held less tsunami

while they worried about their boats, their lives

experiences than their counterparts in the Sanriku

are more important. They finally went to theirarea. The respondent felt that education was theboats; strengthened the ropes before evacuating tomost important and that evacuating to higher

high ground. The second group said they were out

ground should be prioritized over a large sea wallat sea during the time of earthquake. They decided

as a sea wall cannot fully guarantee survival but

move to a deeper sea location and survivled whileproper evacuation and knowledge can..

witnessing the destruction of other boats failed to

In Katsura, a small remote island off the coast

evacuate. The ¿shermen stated that although theyof Shiogama city, response and support might42ೋ෨ࢥ‫ݪࡄڠ‬༭࣬ల 32 ࣢Ȫ2015ȫ

not arrive in time which is why they had set up

obstruction, leading to 13 days of travel.

their own emergency team. The fishermen that
we interviewed also served as ¿re ¿ghters for theĶįġńŰůŤŭŶŴŪŰůŴġŢůťġųŦŤŰŮŮŦůťŢŵŪŰůŴ

island. The team comprised of 20 members from a
total population of 200 residents. Just about 510

5.1 Inland or offshore evacuation

min after the earthquake, they met together and

For those fishermen who decided to evacuate

agreed that this event might be greater than theoffshore, most of them could not go as far as they

1960 Chilean tsunami. The respondents launched

expected and felt they were lucky to survive andpatrol cars for disseminating warning using siren

save their boats, despite experiencing various

as the wireless speakers were not working and attroubles encountered during their overnight staythe same time cleared evacuation routes from thein the sea. However, what made different is how

collapsing debris. Also they called ¿shermen who

fast they perform offshore evacuation and how

were in the sea to come back and evacuate to a

the level of knowledge of tsunami behavior due

school or shrine located at higher elevations. All

to the bathymetry of their port as discussed in theresidents of the island survived the tsunami.

following section. Fishermen in Sanriku area felt
very strong shaking as they were near epicenter

4.3 Problems and difficulties after getting outof the earthquake, leading them to take prompt

offshoreaction. Many of them also had experienced

Based on the surveys, we found common

the tsunami from 1960 Chilean Earthquake.

problems ¿shermen experienced after evacuating

Fishermen in other areas may need more thanoffshore which are as follows:

510 min to check warning information before(1) Coldness: Small fishing boat generally lackmaking their decision. This gap can make theroofs that could protect fishermen from strong

difference between life and death. Many of thewind, rain or snow. For example, snow continued

fishermen that decided not to evacuate offshore

to fall into the evening during the 2011 tsunami.

but evacuated to high ground felt remorse over(2) Loss of connectivity: We found that during

the loss of their boats but were satisfied withthe 2011 event mobile phone networks were

their decision to prioritize their life ¿rst. Most ofdown. Some of portable radios inside the ¿shingthese ¿shing boats are insured, thus if insurance

boat worked but only provided information oncompanies can ensure that fishermen will get

big cities and were devoid of local circumstances.

paid and be able to buy new boats soon afterThus, fishermen had no idea what happened toa tsunami, fishermen may not risk evacuating

their village and when they could return.

offshore and without a doubt, evacuate to higher(3) Starvation: Only a few of the respondents

ground. Based on the experiences of fishermen

carried canned food and water with them during

who survived the 2011 Japanese Tsunami, one

the evacuation. Most of the respondents starved

can conclude that although the historical tsunami

until they could return to land.

background is different between Sanriku area and(4) Debris obstruction: The tsunami destroyed

others, there is a strong determination to evacuate

everything in the port whose remains would

offshore in comparison to areas beyond Sanriku

become debris. This floating debris hamperedwith less tsunami experiences.

navigation between offshore and the port. In
the 2011 event, most of fishermen experienced

5.2 Understanding the topography for better

difficulties returning home due to debris

decision making
Knowing about the tsunami characteristics ofOffshore evacuation of ¿shing boats
 Lessons from the 2011 Great East Japan tsunami and its future challenge
a fishing port is also important. For example, a43real time decision support.

tsunami arrived at a peninsula in the Sanriku areas(2) The influence of highground relocation:

as fast as 30 min or less because the areas are

Most of the ¿shing villages will be relocatedlocated in the deep sea and close to earthquake

to higher grounds after the 2011 tsunami.

epicenter. However due to the influence of theThis strategy was implemented after the

deep sea, boats can reach a safety zone of 50

two great tsunamis in 1896 and 1933. In

meters or deeper within a short period of time.

the case of 1933 tsunami, most villages

On the other hand, for a plains area such as thedecided to relocate to a distance no more

Sendai plains, boats would have to traverse 30

than 400 meters from their original location

km or more to reach the 50 meter sea depth. In

and an altitude lower than 15 m (Suppasri

other words, with the maximum speed of ¿shing

et al., 2014). However, it is clear that after

boat at 20 knots (36 km/h), the boats will needthe 2011, many villages have planned toalmost one hour or more in evacuating offshore

move to areas where the altitude difference

to survive. In other words, although the tsunami

is higher than 30 m and a distance further

may arrive later in the Sendai plains (about

than 400 m from their original location; suchone hour after the earthquake) the boats should

relocation to ensure that all villages will

immediately evacuate. This example shows thatbe safe from future tsunamis because their

the required time for evacuating offshore candestination point will be 4050 m higher thandiffer. Relocation to high ground will definitely

the sea level. Relocation to high ground willaffect the evacuation culture of some fishermen

definitely affect the evacuation culture of

who still prefer to save their boats from tsunamis

some ¿shermen who still prefer to save their

because they should perform the evacuationboats from tsunamis because they should

faster. This action will be more difficult andconduct their evacuations more promptly.

risky for future tsunamis. Hence, education forThis action will be more difficult and risky¿shermen based on localized situations is vital infor future tsunamis. Nevertheless, similar

ensuring survival.

to the past experiences, many of villagers
returned to the coastal area. Therefore, long

5.3 Research Implications
Although there is still no clear answer interm study of the influence of highgroundrelocation is needed.

regards to the best offshore evacuation solution,(3) Education activities: As mentioned in thesome important key future research has beenprevious section, activities such as increasing

identi¿ed.

disaster awareness, improving understanding(1) Offshore tsunami evacuation map: Byof topography of the coastal area, andcompiling simulated tsunami height andoffshore evacuation drills are necessary to

velocity from probabilistic tsunami hazard

optimize the response against the futureassessment and damage estimation of ¿shing

events.

boats using fragility curves, offshore tsunami
evacuation maps can be created providingłŤŬůŰŸŭŦťŨŮŦůŵ

information on successful probability ofthe offshore evacuation at each point fromWe greatly appreciate the assistance of Mr.

the shoreline. The map can be developed

Susumu Tsuboi together with other six ¿shermen

for application for smart phones or tablet

in Tadakoshi, Mr. Yasuhiro Sato and together

computers making use of GPS technology aswith other eight fishermen in Niranohama and44ೋ෨ࢥ‫ݪࡄڠ‬༭࣬ల 32 ࣢Ȫ2015ȫ

Mr. Yoshietsu Atsumi together with other three

JMA (2014)

fishermen in Yagawa for their time and kind

http://www.jma.go.jp/jma/cooperation of the interview. Valuable commentspress/1404/03c/201404031810.html (infrom Dr. Kanako Iuchi are highly appreciated.

Japanese) (Accessed: 3 April 2014)

We express our deep appreciation to the special

Kahoku Shinpo Newspaper (2014)

research funding from the Government of Japan

http://www.kahoku.co.jp/

and Tokio Marine & Nichido Fire Insurance

tohokunews/201404/20140405_73019.html (inCo., Ltd. and through the International Research

Japanese) (Accessed: 3 April 2014)

Institute of Disaster Science (IRIDeS) at Tohoku
University.

Kahoku Shinpo Newspaper (2013a)
http://www.kahoku.co.jp/
news/2013/11/20131124t73014.htm (inœŦŧŦųŦůŤŦŴ

Japanese) (Accessed: 24 November 2013)
Kahoku Shinpo Newspaper (2013b)

47 News (2014)

http://www.kahoku.co.jp/

h t t p : / / w w w. 4 7 n e w s . j p / l o c a l n e w s /news/2013/10/20131027t21006.htm (inaomori/2014/04/post_20140404100241.html

Japanese) (Accessed: 27 October 2013)(in Japanese) (Accessed: 3 April 2014)
ABA News (2014)

Katada, T., Murasawa, N. and Kanai, M. (2012)
Inspection of the rule development effect about

http://www.abanet.com/news/news011.html

FishingBoat Evacuation against Tsunami(in Japanese) (Accessed: 3 April 2014)

Ƚ Example of Correspondence of fishermen

Cabinet of¿ce, Government of Japan (2012)

belonging to Ochiishi fishery cooperative in

http://www.bousai.go.jp/jishin/nankai/model/

Nemuro City in 2011 Tohoku earthquake and(in Japanese) (Accessed: 29 August 2012)

tsunami Ƚ , Disaster information, 10, 103112

CBS (2012)
http://www.cbsnews.com/news/tsunami

(In Japanese with English abstract)
Mainichi Newspaper (2012)

warninginhawaiidowngradedtoadvisory/

http://mainichi.jp/select/Fisheries Agency (2006) Guideline for disasternews/20121208k0000e040155000c.html (inresilient ¿shing community development, 165pp.
Hodaka, K. (2012)h t t p : / / w w w. h o d a k a  k e n i c h . c o m / 3 . 11 
coverage/2012/05/12125933.php (in Japanese)(Accessed: 12 May 2012)
JMA (2012)
http://www.jma.go.jp/jma/press/1212/07b/201212072000.html
JMA (2013)

Japanese) (Accessed: 14 December 2012)
Manning, Jeff (2011)
http://www.oregonlive.com/paci¿cnorthwest
news/index.ssf/2011/03/post_18.html
NHK (2014)h t t p : / / w w w 3 . n h k . o r. j p / n e w s / w e b _tokushu/2014_0311.html (in Japanese)(Accessed: 11 March 2014)
Ohashi, T., Koshimura, S. and Imamura, F.
(2007) Design of a tsunami hazard map on

http://www.jma.go.jp/jma/

the sea to reduce fishing boat user’s damage,press/1310/26a/201310260410.html

In proceeding of the coastal engineering

Kahoku Shinpo Newspaper (2012)
http://www.kahoku.co.jp/
news/2012/12/20121208t73037.htm (inJapanese) (Accessed: 8 December 2012)conference (JSCE), 54, 13511355. (InJapanese with English abstract)
Oregon Sea Grant (2007)
http://seagrant.oregonstate.edu/sgpubs/

Offshore evacuation of ¿shing boats
 Lessons from the 2011 Great East Japan tsunami and its future challenge
onlinepubs/g07004.pdf
Tokachi Mainichi Newspaper (2012)45

Suppasri, A., Muhari, A., Futami, T., Imamura,F., and Shuto, N. (2013) Loss functions of

http://www.tokachi.co.jp/

small marine vessels based on surveyed data

news/201205/201205180012597.php (inand numerical simulation of the 2011 Great

Japanese) (Accessed: 18 May 2012)

East Japan tsunami, Journal of waterway,

Tokachi Mainichi Newspaper (2013)h t t p : / / w w w. t o k a c h i m a i l . c o m / u r a h o r o /backnumber2013.php?d=20130523 (inJapanese) (Accessed: 16 May 2013)

Port, Coastal and Ocean Engineering, 140 (5),04014018.
Suppasri, A., Yasuda, M., Abe, Y., Fukutani, Y.,
Imamura, F. and Shuto, N. (2014) Relocation

Torii, H., Sawamoto, J., Segawa, N., Sugino, E.

after tsunamis in the Sanriku area and theand Nomura, Y. (2010) Tsunami early warning

condition of ¿shing villages two years after theand evacuation support system for fishery2011 Great East Japan tsunami, Post tsunami

workers by mobile phones, In proceedings ofhazard reconstruction and restoration, Springer

the 2010 IEEE 24th International Conference

Monograph (in print)

on Advanced Information Networking andUnited States Coast Guard (2013)

Applications Workshops, Perth, WA, 2023

h t t p : / / w w w. u s c g n e w s . c o m / g o /April 2010, page 704709.

doc/4007/1930237/Tsunamievacuation

Suppasri, A., Muhari, A., Futami, T., Imamura,ruleestablishedforHawaiianIslands

F. and Shuto, N. (2013) Loss functions ofcommercialharbors#sthash.zFsT0U2d.dpuf

small marine vessels based on surveyed dataand numerical simulation of the 2011 Great
East Japan tsunami, Journal of Waterway,
Port, Coastal and Ocean EngineeringASCE(published online)