TSUNAMI THREAT TO' PORT ALBERNI

Prepared for

Allan M. McCraeConsulting Civil Engineer

Victoria, B.C.

and

Reid,.. Crowther- & Partners LimitedConsulting Engineers and Planners

Vancouver, B.C.

by

Sydney o. Wigen, P.Eng.4053 Nelthorpe Street

Victoria, B.C.

February 1977

IIii

-~

Contents

Abstact

Alternative Approaches

Numerical For~casting

Historical Forecasting

Source Data

Data Extraction

Port Alberni - Tofino Relationship

Tsunami Hazard, by Zone of Or~gin

Tsunami Frequency at Tofino and Port Alberni

Characteristics of the 1964 Tsunami at Port A1berni

Contribution of Tide to Tsunamis at Port A1berni

Tsunami Threat to Lugrin- Creek Site

Mitigation of Tsunami Damage

Acknowledgement

Ref.er.enc.es

Appendix: A

Page

5

6

6

7

7

8

10

12

15

19

21

21

22

22

23

25

Illustrations and Tables

Page

Figure 1 Tsunami wave heights 10

Figure 2 Alaska - Aleutian Islands. Earthquake

epicenters and magnitudes; and maximum

tsunami wave 'produced at Tofino.

Figure 3 Kamchatka Peninsula, Kuril Islands, and Japan.

Earthquake epicenters and magnitudes, and

max.lmumctsunamj, ',wave produced at Tofino.·

Figure 4 Number of tsunamis recorded at Tofino, ,with

maximum. wave equal or larger than value'give

in ordinate.

Figl.-rre'- 5 Tsunami of March 27, 1964 as recorded' at

-To fino and Port Alberni.

16

17

18

20

Table 1

Table·-2

.Summary of earthquakes studied, and tsunamis

identified at Tofino and Port Alberni.

Maximum tsunami waves at Tofino and Port

Alberni.

\ ..

9

II

/

5

Abstract

A historical approach has been undertaken in this report to

evaluate the threat of tsunamis to Port Alberni. From catalogues

of tsunamis, a list was compiled by area of more than 100 major

tsunamigenic events occurring throughout the Pacific since 1900.

Availab~eTofino and Port Alberni analogue tide records were

studied to find evidence of the waves reaching the Coast. Twenty-one

of 70 events examined showed a tsunami at 'I'ofLno, and 5 of 19 at

Port Alberni.

The size of maximum tsunami waves at Port Alberni was found

to b~approximately double that at Tofino, where both stations had'

recoTded the same tsunami. It was concluded that Tofino records.

could..be used to estimate the. frequency of tsunamis at Port Alberni,

and the probable maximum waves that would have been recorded •

.;., '~..- .

Of' the 21 tsunamis known·to have reached the coast, 15 came

from:::the region ,between Gulf of Alaska and northern Japan. In the

half century of records studied, the 1964'tsunami was.highly

destructive in Alberni Inlet; the 1960 event was moderately damaging;.

and 3~more...tsunamis may have been close to the point of doing

damage.

In designing for a one-in-200 year event in Port Alberni,

at least one tsunami of the 1964 size must be anticipated.

TSUNAMI THREAT TO PORT ALBEmTI

Alternative Approaches'to Forecasting. Tsunami Hazard

~vo alternative procedures·canbe·applied to forecast the

runup of tsunamis in Alberni Inlet, one numerical, and the other

his t.o'r.Lca.L,

Numerical Forecasting

A hydrodynamic numerical modelof'Albernilnlet and approaches

would be developed. The accuracy of the model would be calibrated

by· applying normal· tides at the entrance to.the model, and

COIDp-ar±n.g simulated tides .produced·at check points in the model. .

agains-t. those occur-r.tng dn the prototype., Simulated ·.tsunamis from

various· sources in the Pacific Ocean could ·then ·beapplied to the

mode'l-centrranee., and ·the response at the head" of the Inlet, or at

any-other location within the model could.be calculated.

Numerical forecasting has the advantage that as many different·

source conditions as required may be tested, and the probable most

criticaL events may vbe determined. However, scientists engaged in

this type of·study·advise that the·investigation of a waterway as

complex as Alberni Inlet and Barkley Sound would probably require

at least six months ·of research time. The cost of such a study,

including computer support, appears to be prohibitive for Lugrin

Creek planning, but might be feasible as a research project

correlated with overall planning for the head of Alberni Inlet.

A limitation of the numerical modelling technique must be

recognized, that the precise nature of the delta area becomes

critical in the Tunup interpretation. Simu~ated response of the

model might be changed significantly by slight changes in the

assumptions regarding the delta.

7

Historical Forecasting .

The historical approach requires a review of tsunamis known to

have occurred thr~ughout the Pacific Ocean. Records and publications

are examined to find which of these tsunamis reached' the" British Columbia

coast. For a study of Albemi Inlet and approaches~ the principal rec­

ords are the analogue diagrams from tide gauge s~ations at Port Alberni

and Tofino. From such a study it becomes possible to identify which

zones of the Pacific represent a potential tsunami source~ and to make

some estimate of the frequency with which tsunamis may reach the Coast.

Such a study has been undertaken for .this report, and from the data col­

lected and summarized we can draw some conclusions on the tsunami threat

to Port Alberni.

Source.. Data

For this study, available catalogues of tsunamis at the Inter­

nationaL'Tsunami Information Center in Honolulu were reviewed. More

than.lOO earthqu~kes with Richter magnitudes between·7.5 and 8.6, oCcur­

ring since 2900 were tabulated by" area. Some known exceptionally large

earthquakes of earlier years were also listed. Approximate travel times

for:waves from each epicenter to reach Tofino or Port Alberni were ex­

tracted.from tsunami travel time· charts.

Through the co-operation of the Tidal and Current Section, Canadian

Hydrographic Service t in Victoria, and Marine Environment Data Service~

Ottawa~ analogue tide gauge records from Tofino and Port Alberni were

made available. The records were scanned at the estimated arrival times~

and any evidence of a tsunami was listed. Port Alberni original gauge

records were available from 1963 to 1976~ but with interruptions. The

Tofino tide gauge has been operated fairly continuously by the Government

of Canada since 1906, and for most of. these years~ the original records

were also available. However, there are some years of Tofino tide

8

records that now exist only on microfilm, and only a few prints from

these records have been available in time for use in the preparation of

this report.

Detail on the original records is sufficiently clear that generally

a tsunami registering a wave of 2 em or more at Tofino can be identified.

On the m~crofilm, whether similar tsunami oscillations can be recognized

is dependent on the quality of the' original record.

Data Extraction

Appendix A contains a listi;ng of the' tsunamigenic events of the

past' century that was prepared for this s tudy, grouped: by areas, the

Richter magnitude of the earthquake, and its depth of focus in kilometers s

where-available. The arrival time of the initial wave at Tofino and its

height in centimeters is listed, followed by R or Fto indicate whether

the wave was rising or EaLl.Lng ; The time of commencement and height of

th~~umwave for each tsunami, as recorded at Tofino, is also listed.

AlL_t±mes are gi~en in Universal Time (U.T.). A similar extraction of

tsunamis was made for Port Alberni. Table 1 summarizes the number of

events' by area and by magnitude, the number of these for which tide

r ecozds were available for scannfng , and the number of tsunamis identi­

fied on 'Tofino and Port Alberni tide diagrams~ Twenty-one of 70 events

showed a tsunami at Tofino, and 5 of 19 at Port Alberni.

In past tsunami data extraction it has been cornman practice to

measure the height of a wave f;rom trough to crest, with the inf~uence

of the tide included. For this study, intercomparison of the 'waves at

Tofino and Port Alberni was required, so the contribution of the tide

has been deleted. This has been done by measuring each trough or crest

as the maximum displacement from an assumed tide that would have occurred

had there been no tsunami.

Tidal Records Scanned andNumber of Events by Magnitude Visible Tsunami Identified

Area >7.9 7.5-7.9 <7.5 UnknoWn Total Tofino Port Alberni

1. Chile - Peru 4 10 2 16 8/2 5/0

2. Ecuador - Mexico 2- 8 1 11 7/0 I/O

3. Baja California -Alaska Peninsula 2 .1 3 6· 3/0 1/0

4. Gulf of Alaska - Aleutians 1 3 10 6/5. 3/1

5. Kamch~tka - Kurils 7 3 ·1 11 9/7 4/2

6. Mariana - Japan Trench 4 9 13 10/3 2/1

7. .Ryukyu - Philippine Trench 5 8 13 9/0 2/0

8. S. China - Sulu - Celebes Sea 3 3 6 3/0 0/0

9. Java Trench - Banda Sea 1 3 1 5 3/0 a/a

10. N. Guinea - Bismarck Archipelago 2 2· 1/0 .0/0

II. Solomon Sea - New Hebrides 4 9 13 6/1 0/0

12. Tasman Sea 2 2 2/0 0/0

13. Kermadec - Tonga Trench '4 1 5 2/2 a/a

14. Hawaii i 1 1/1 1/1

.43 59 9 3 114 70/21 19/5

Table 1. Summary' of earthquakes studied,. and

tsunamis identified at tofino and Port Albern!

'.

In a typical case,

as shown in Figure 1, the

height of the initial wave

is taken as X-B, and not

X-A. Similarly the maximum

wave is not Y-Z, but (Y-~)

+ (D-Z).

(Right) Figure 1.

Tsunami Wave Heights

Port Alberni - Tofino Relationship

10

y

II

I

r :ei

z

To establish the frequency and hazard of tsunamis at Port Alberni

from...the very limited data would require an extrapolation that would have

little validity. However, Tofi~o, only "lOO kilometers ~way, offers a much

longer-history. The question comes up of whether. the response of the two

ports-·-is sufficiently similar that one can make any assumptions about tsu­

namfs.cat; Port .AJ.berni from those recorded at Tofino. Although the char­

acteristics of the waves are markedly different, we can attempt a correla­

tion of the maximum waves of tsunamis observed at both locations. The

first comparison ~s for the 1960 tsunami from Chile which produced the

Lar-gestrwave ~ecorded to that time at Tofino. No gauge wa? operat.Lng at

Port Alberni, but the waves were reported to be large enough. to damage

log booms; one rise of about 2 meters was described at the paper loading

dock; and offices at MacMillan Bloedel Limited were sufficiently con­

cerned that the Company agreed to co-operate with the Canadian Hydro­

graphic Service in the installation and.operation of a pennanent tidal

station, principally to have its records available in the possible event

of a future tsunami.I

This fortuitous decision has made possible the data for this study,

and even though the disastrous 1964 tsunami did exceed the gauge range

11

and put it out of action briefly, the record none-the-less has been

invaluable.

Subsequent to 1960, five tsunamis were registered on both the

Tofino and Port Alberni tide gauges. Table 2 gives a comparison of the

maximum waves for which recorded or estimated h~ights can b~ given.

MaximUm Wave Maximum WaveDate Tsunami Source Magnitude Tofino " Port Alberni

May 22, 1960 Chile 8.5 126 200 (estimate)

Oct 13, 1963 S. Kuril Is. 8.2 16 27

Mar 28, 1964 Alaska 8.4 240 800 (estimate)

May l6, 1968 N. Japan 8.2 12 24

AugIl., 1969 S. Kuril Is. 7.8 6 4

Nov 29, 1975 Hawaii 7.2 9 10

--Tab.le 2.. Maximum Tsunami Waves at Tofino and Port Alberni

For the larger tsunamis there is a reasonable correlation between

the-,::two ports, with the maximum at Port Alberni averaging ab-out twice

the~"height" of the maximum at Tofino. In addition there were several

examples of both ports having no response to "a tsunami~ and no occasion

onrecord:when one responsed and the other did not.

On the strength of this evidence we conclude that the frequency of

tsunamis occurring at Tofino from various sources establishes the fre­

quency for Port Alberni, but "that larger size waves must be expected

at Port Alberni than Tofino for major events.

12

Tsunami Hazard, by Zone of Origin

Less than one hundred years of systematic seismic and tidal

records are available for tsunami studies. Regi~nswith tsunamQgenic

potential may exist in the Pacific that have produced no major earth­

quakes in the past century. Understanding of the plate tectonic move­

ments producing most of these earthquakes is very recent. It is not

known whether seismic zones are alternately active and quiescent 'over

decades or centuries, or whether the frequency of earthquakes and

tsunamis is fairly constant. Of necessity then the history of activ­

ity during the past century becomes the' criterion we must use to

estimate future threat.

Peru-Chile Trench

Tofino.tide'records were available for 8 major earthquakes of

the past 60 years. Only 2 showed evidence of a. t.sunami., but one' of

these~ in 1960, was the second largest wave registered at'Tofino.

The tsunami from this earthquake was one of the most severe on

record in the Pacific, and caused severe damage and casualties in

South.America, Hawaii, and Japan.

Ecuador-Nexico

The subduction zone of the Middle America Trench has produced

a number of tsunamis, but these appeal:" to be directed away from the

Canadian west coast. Tofino tide records showed no 'evidence 'of

tsunamis resulting from any of seven earthquakes in this areae

Baja California - Alaska Panhandle

Earthquake movements tend to be strike slip, having hori­

zontal rather than vertical displacement, and therefore, are

generally non~tsunamigenic. Two records examined showed no tsunami.

13

The most recent of these, with~a magnitude of 6.7, occurred on

Dec. 20, 1976, 200 kilometers west of Tofino. A subduction zone

lies off Vancouver Island and Wash~ngton, associated with local sea

floor spre~dingo The Earth Physics Branch of Energy, }lines' and Re­

sources Canada does not rule out the possibility of a tsunami from

this source, but indicates that if any occur here they are suffi­

ciently rare that the last wa~ generated before the time of recorded

history on the Coast.

Gulf of Alaska~Aleutian'Islands

Five of six large earthquakes'produced'tsunamis at Tofino; two

additional earthquakes in the western Aleutians, for which Port

Alberni but not Tofino records were available,' did not. The 1964

earthquake, near Anchor.age,'produced the'l~rgest' tsunami on record

at Tofino and Port Alberni.

Kamchatka Peninsu1a~Kuti1 'Islands

Of nine events examined seven earthquakes produced tsunamis at

Tofino. Of these, the magnitude 8.2 earthquake off Kamchatka regis­

tered the largest maximum wave at ,Tofino from this area, 58 em.

Mariana-Japan Trench

Tofino tide records were available for the time of 10 major

earthquakes, and of these 3 showed tsunamis. Epicenters of these

were all ,off Hokkaido and northern Ronshu~ The largest maximum

wave at Tofino from this area, of 23 em, was produced by the Great

Showa Sanriku Tsunami of 1933, that killed thousands of people in

Japan.

14

Ryukyu Trench-New Guinea

In areas 7 - lO.on Table 1, from southern Honshu to the

Philippines, Indonesia and New Guinea, Tofino records were examined

for 16 earthquakes, and none of these showed evidence ofa tsunami.

Solomon Sea-New Hebrides .

One earthquake on the northeast shore of the Solomon.Islands

produced a 6 em maximum Wave at Tofino. No other tsunamis from

this area showed on the records examined.

Tasman Sea

Two records examined showed no evidence of a tsunami at

Tofino •.

Kermadec-Tonga Trench

-~¥o earthquakes studied, of magnitudes 8.0 and 8.3, generated

tsunamis at Tofino with maximum waves of 12 and 9 em respectively.

Generally, the southwest Pacific would appear from the foregoing

results, and from the location of tsunami generating areas relative

to Tofino and to intervening island arcs, to offer no significant

tsunami threat to the British Columbia coast.

Hawaii

The magnitude 7.2 earthquake of November 1975 is the only

tsunamigenic event from this area on record at Tofino. It registered

a maximum wave of 9 em. The previous significant earthquake in

Hawaii occurred in 1868. Whether a major Pacific-wide tsunami could

originate from this area is unknown.

15

Tsunami Frequency at Tofino and Port Alberni

The region from Gulf of Alaska.to Japan, areas 4,5, and 6 in

Table 1, clearly provides the most significant tsunami threat to

Port Alberni. At least 34 tsunamigenic earthquakes occ.urred in 80

years, and of' 25 of these for which' Tofino tide records wexe avail­

able at :the time of the study, 15 sho'i1 clear evidence of a tsunami.

·Locations of epicenters for this region are shown on Figures 2 and

3. With 'each-is shown the magnitude of the earthquake, and the

height of the maximum wave generated at Tofino from the event.

Eighteen of the earthquakes from the region registered a magnitude. -

of 8.0 or larger, a size for whichaPaeific-wide tsunami warning is

autqmatically issued from the Honolulu Observatory.

In the. p~riod of record '. six tsunamis reached Tofino from the

rest of the Pacific, the one in 1960 being-large enough to cause

damage. Figure 4 shows the number of tsunamis recorded at Tofino ,

with maximum wave height larger than any given value. Plotted

logarithmically, the result is approximately ·linear. The signifi­

cance of this relationship is not clear, _since the sample is an in­

complete record of the number of tsunamigenic events_that occurred,

and_furthermore, .it groups all tsunamis regardless of the area of

origin•.

Seismologists who have studied. earthquake frequencies, and who

were queried during the preparation of this report·, warned _against. .

attempting to extrapolate .tsunami frequencies from the presently

known history. In particular they cautioned .against identifying the

frequency with which the rlisastrous tsunami of 1964 would be equalled

or .exceeded. It was felt that mathematical expressions of probability

and frequency_ had little relevance to the data, since the mechanisms

producing tsunamis, or focusing their direction of travel from sourc.e

are not well understood.

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Figure 3. Kamchatka Peninsula, Kuril Islands and Japan

Earthquake Epicenters and Magnitudes, andHaximum Tsunami Wave Produced at Tofino

18

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Figure 4. Number of tsunamis recorded at Tofino, withmaximum wave equal or larger than value given in ordinate.

19

Notwithstanding the validity of this point of view, some con-

,- elusion on tsunami hazard is a specified requirement of the Lugrin

Creek Study, and the material here compiled is the most comprehen­

sive set of data on tsunami impact on Tofino and Alberni Inlet yet

assembled. From these data it is apparent that tsunamis reaching

the British Columbia coast, and specifically Alberni Inlet, are a

much mor.e common phenomenon than had generally been recognized. In

the past half century, one tsunami has been highiy destructive, and

another moderately damaging. Assuming an amplification on waves

recorded at, Tofino,as evidenced by the data in Table 2, 'three more

tsunamis in this same period may have been close to the' point of

being moderately damaging. Earlier tide records back to 1906, may

give some further indication on tsunami freque~cies when the micro­

films are studied. Newspapers prior to .-1906 may also provide in­

fo rmatri.on if events comparable, to the 1964 tsunami occurred subse­

quent to the development of Alberni as a port~

On ~resent knowledge, for a design criterion based 'on a one in

200 year event, at'least one tsunami of the 1964 size must be expected.

Characteristics of the 1964 Tsunami at Port A1berni

Figure 5 (taken from Marine Sciences Directorate ~illnuscript Re­

port Series, No. 36)" shows the analogue trace of 'the 1964 tsunami at

Tofino and Port Al.be'rnd., For the first 8 hours the 'Port Alberni gauge

was for the most part out of service, and waves exceeded the range of

the gauge. However, parts of the first and second rise were recorned,

and the maximum crest was identified with accuracy by the water level

mark on the gauge house wall, at 20.9 feet (6.4 m). The first three

crests were recorded also on the Soroass River gauge, and helped in

recreating some of the missing record. The second or maximum crest

reached an elevation of 19.6 feet (5.6 m) on the Somass River gauge,

showing a drop in tsunami height beyond the end of the harbour.

TSUNA~I WEST COAST OF CANADA MARCH 27 -29 1964

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31Figure 5. Tsunami of March 27, 1964

as recorded at Tofino and Port Alberni

21

Of the 5 tsunamis at Port Alberni for which analogue records. .

are available only the 1964 event shows dominant waves with a period

of about 90 minutes. This is also the apparent period of a natural

seiche in the Inlet, and corresponds closely with one of the natural

frequencies of Alberni Inlet calculated. by Murty and Henry (1972).

Contribut:Lon of Tide to Tsunamis at Port Alberni

In the 1964 tsunami the first waves came in vThen the tide was

cresting at about 10 feet (3.0. in), very close to the 10.4 feet (3.2 m)

level of higher high water mean tide.;

Since the elevation of higher high water, large tide is 12.2 feet

(3.7m) and the all time extreme tide (non tsunamis) is 14.3 feet

(4.4m), in a once in 200 years tsunami the prospect of a higher tide

contributing substantially to a tsunami flood crest is small. It is

more likely that a minor variation in the s t rengfh of inlet response

to a.particular tsunami would have more impact than tide on the flood

crest ·reached.

Tsunami Threat to the Lugrin Creek Site

Unless exceptionally high dikes can be provided. in any Lugrin

Creek development, the possibility that a tsunami' will flood the area

has to be accepted.

With the present capabilities of the Tsunami Warning System in

the Pacific, and of Civil Defense authorities in Canada, it is probable

that at least 2 hours warning of an impending tsunami can be given, and

that evacuation of people ~ivin~, working, or enjoying recreational

facilities in the area can be effected. This potential need for evac­

uation needs to be recognized in designing roads leading from the low

lying ·area.

The remote .threat of a severe tsunami generated near the coast

probably does not warrant undue concern for the proposed Lugrin Creek

development, but could be a significant factor in siting an atomic

power plant, or major oil terminal in Port Alberni.

As an additional but hidden cost of development, periodic evac­

uation for tsunamis, that could, but do not actually flood the area

must be anticipated. Such false alarm evacuations may be anticipated

once per decade, or oftener, based on the history of tsunamis in the

Pacific.

Mitigation of Tsunami Damage

Damage from tsunamis may result from flooding.when the water is

raised to abnormal levels, and from the very strong currents asso­

ciated wi.th the rapid changes in water level. Dikes will be scoured,

log booms destroyed, and vessels driven ashore.o!, overturned. Damage

or destruction may occur from the dynamic pressures and pressure dif­

ferentials on the faces of structures, and by excessive'erosion of

the foundations. Logs and floating debris become damaging or destruc­

tive missi.les.

Experience in parts of the Pacific has shown that trees, closely

spaced, reduce some of these hazards. Retention or enhancement of

natural vegetation should be encouraged during any development.··

Acknowledgement

Of many people who have advised or assisted with aspects of thisstudy I would like to acknowledge in particular the support and interestof G. Pararas-Carayannis and M. Ching, International Tsunami InformationCenter; G. Miller (deceased) and H. Loomis, Joint Tsunami ResearchEffort; w. Rapatz and J. Manson, Tidal and Current Survey; G. Rogers,Seismology and Geothermal Studies; R. Brazee, National Geophysical andSolar-Terrestrial Data Center; and J. Derr and R. Kangas, NationalEarthquake Information Service.

:1iII

:1II

I,·1

!IIi

.''11

.,

.1;'1.,"

j

:1

23

References

Braddock, R.D. 1975. An analysis of the conventional tide well.

Applied MathematicsPreprint No. 86, University of

Queensland.

Cox, D.C. and George Pararas-Carayannis, with revisions by J.P.

Cal.ebaugh , 1976. Catalog of tsunamis in Alaska•. \lorld

Data Center. A for Solid Earth Geophysics, Boulder.

Henry, R.F. and T.S. Nurty. 1972. Resonance periods of multi­

branched inlets with tsunami amplification. Marine

Sciences Directorate Ottawa. Manuscript Report Series

No. 28.

Iida, K. 1961. Nagnitude, energy, and generation mechanism of

tsunamis, and catalogue of earthquakes associated with

tsunamis. Tenth Pacific Science Congress.

Iida,_ K•., Doak C. Cox, and George Par-aras-Carayannf.s ," 1967. Pre­

.Limfriaz'y catalog of tsUnamis occurring in the PacifiC.

Ocean. Hawaii Institute of Geophysics, University of

Hawaii.

Neyers., H.; R.J. Brazee, J.L. Coffman, and S.R. Lessig. 1976. An

analysis of earthquake intensities and recurrence rates

in and near Alaska. National Geophysical and Solar­

Terrestrial Data Center, Boulder. NOAA Technical

Memorandmn EDS NGSDC-3.

Nurty, T.S. and L. Boilard. 1970. The tsunami in the Alberni

Inlet caused by the Alaska earthquake of March 1964.

Proceedings of the international symposium on tsunamis

and tsunami research. Ed. W.N. Adams. East-West Center

Press. Honolulu. p. 165-187.

1964. Tsunami of March 27-29; 19'64,.

Department of Mines and Technical

24

Nurty, T. S. and R. F. Henry. 1972. Some tsunami studies for the

west coast of Canada. Marine Sciences Directorate,

Ottawa. Manuscript Report Series No. 28.

Murty" T~S., S.O. Wigen, and R. Chawla. 1975. Some featur.es of

tsunamis on the Pacific coast of South and North America.

Narine Sciences Directorate, Ottawa. Manuscript Report

Series No. 36.

National Ocean Survey. 1971. Tsunami travel time charts. Na­

tional Ocean Survey, NOAA. Rockville,'Md.

Pararas-Carayannis, G. 1969., Catalog of tsunamis ,in the Hawaiian

Islands. World Data'Center,-A Tsunami. U.S. 'Coast &

Geodetic 'Survey.

Silgado ~. Enrique. 1974. Historia de los grarides tsunamis'pro­

ducidos en- la'costa occidental de America del Sur. Centro

Regional de Sismologia para America del Sur. Lima.

(in Spanish).

Soloviev,'S.'and Ch, N. Go. 1969. Catalog of tsunamis in the

Pacific Ocean. Sakhalin Complex Scientific Research

Institute. (in Russian)

Wigen, S.O. ,1960. Tsunami of May 22, 1960, west coast of Canada.

Technical report, Marine- Sciences Branch.

Wigen, S.O. and W.R.H. l~ite.

west coast of Canada.

Surveys. Victoria.

.;'"

,:",;~.' .. " ',')"1::',."

''''.";1''.''.,,',"

Appendix A

Tabulation. of earthquake epicenters, by area,

and tsunami waves registered 'at Tofino

".'.':

.\

TRAVEL TIMES OF MAJOR TSUNAMIS

AREA OF ORIGIN: Chile ... Peru GkdGl~ SITE ~,ECORPEn:, Tofinoi • ; ,. : J . '

HOUR HRS FRON EST.AR. INIT.WAVE MAX. WAVEYEAR 1'10. DAY. (D. T.) LAT. LONG. }fAG. DEPTH GAUGE (U. T. ) ARR. HT. ARR. HT. PERIOD' COMMENTS

1868 Aug 13' 1645 l8S 7lW

1877 May 10 0059 21.55 ' 71W

1906 Aug 17 0040 338 72W 8.4 16 '1/2

1922 Nov 11 0433 28.58 70W 8.3 16 2033 2030 3R 12/0333 27F1928 Dec 1 0406 358· 72W 8.0 16 '1/2 2036 No tsunami1943 Apr 6 1607 31.58 71.4W 7.9 10 16 7/0807 No tsunami1959 Feb 7 0937 48 81.5W 7.5 0 12 1/2 No record1960 May 21 1003 37.58 73.5W 7.5 17 22/0303 No tsunami'

1960 May 22 1911 39.58 74.5W 8.. 5 17 23/1211 1221 22R 1730 126F

1966 Oct ,17 2142 10.7S 78.7ii1, 7.5 , 24 ,'13 1/2 ,No record

1966 Dec 28 0818 , 25.58 70. 7iii 7.6 32 ,16 ' No record

1967 Dec 21 0225 21.7S 70.0W 7.5 15 1/2r " , No tsunami- .~ ,

1970 Nay 31 2023 9.28 7S.aW ' 7.8 43 13' 1/2 No tsunami,

1971 July 9 0303 32.58 71.2W 7.5 58 16 1/2 No record,

1974 Oct 3 1421 11.58 nv. 7.7 13 13 1/2 No tsunami

1975 May 10 1428 38.13 73, •• 2W' 7.8 6 16 1/2 No tsunami

'.,

TRAVEL TIMES OF MAJOR. TSUNAMIS

AREA OF ORIGIN: Ecuador - Mexico• ' :' 'j , .' ~. I

GAUGE SITE ~EPO~TJED;' _T_of_i_n_o _

ERS FROM ES~.ARt INIT.WAVE MAX.WAVELONG. MAG~ DEPTH GAUGE .(U.T.) ARR. UT. ARR. HT.

HOURYEAR HO. DAY (~)

1906 Jan· 31 1536

1928 June 17 0319

1932 June 3 1037

1932 June 18 1012

1934 July 18 0136

1941 Dec 5 2047

1950 Oct 5. 1610

1953 Dec 12 1731

1957 July 28 0840

1958 Jan 19 1407

1973 Jan 30 2101

LAT.-IN.16.2N

18.5N

IB.5N

8N

8.5N

10.4N

3.5S

16.5N

1.5N

18.5N

81.5W 8.6

98W 7~8

:.104.2W 8.1

103.5\>1 .7.8.

82.5W. "7.7

83W 7.5

85.7W 7.7I

81\>1 7.8

99.0W 7.9

79.5W 7.4103W . 7.5 .

95

60. 43 .

12 1/2.

'9

7 1/2

7 1/2

12'

12

11 1/2

12

8. 1/.2

12 1/2.

a.,',

PERIOD COMMENTS

No tsunami

No tsunami

No tsunami

No tsunanii

No record

No record

No record

No tsunami

No tsunami

No tsunami

"

---_._._----.._...._... _... _.. .. ····- ...~·:."':?c-:::·.:= .._.;;:t:·"·.'i',,,·::~i!

I:';"",.", '"'""·"";'''''A"7' I., , • _

AREA OF ORIGIN:Baja California ­Alaska Panhandle

. ~;"" '""~'."., ,.".,,~,

TRAVEL TIMES OF MAJOR TSUNAMIS

pAUG~ ST.tE R¥~d~~p;' ~To~f~i~n~o ~ ___I

fIRS VROH EST.AR. INIT.WAVE ' MAX.WAVELONG. }-rAG. DEPTH GAUGE (U. T.) ARR. HT. ARR. HT. PERIOD'

HOURYEAR MO. DAY (U.T.) LAT.

1906 Apr 18 1312 38N

1928 Feb 9 0304 49N '

1946 June 23 1713 49.8N

1949 Aug 22 0401 ,53.7N

1958 July 10 0615 , 58.6N

1976 Dec 20 2033 49.0N

123W 8.25

125W ',5.8'

124.9W 7.3, '

133~2W, 8.1

137.1W 7.9

i28~8W '6.7

3

1 1/2

3

1

COMMENTS

No tsunami

No record

No tsunami

AREA OF ORIGIN: 'Gulf of Alaska - Aleuttans

TRAVEL TIMES OF MAJOR TSUNAMIS

.: .' I I. 1.,:,( • .GAUGE SItE RECq~p~D: T.;..;."o....,:f:..:;·i:..:;n:..:;o _

HOURYEAR MO. DAY (U.T.)-,---1$97 Sept 10 2140

1899 Sept 4 0022

1929. Mar 7 0134

1938 Nov 10 2018

1946 Apr. 1 1229

1957 Mar 9 1422

1964 Mar 28 0336

1965 Feb 4' 0501

19'65 Mar· 30 0227

1975 Feb 2 0843

','

LAT.

60N

60N

51N

55.5N

53.5N

51.3N

61.1N

51.3N

SO.6N

53.5N

In~S FROM ~sT,AR. INrr.WAVE l-fAX.WAVELONG. MAG~ DEPt!! GAUGE /1], T.) ARR. HT. ARR. HT. PERIOD'

140W 8.6 .

·142.3W 8.

l70W· 8.1 5 ... · 0634 06394F ,0800,llF

158W 8.3 4 11/0030 001112R '0125 27F

l63.0W 7.4 4 u: 1700 ·1650 21R '.20,52 58F

17S.8W 8.3 6 2022 1907·14R1Q/013749R

147~7W 8.4 33 4· 0736 . 0700 ~9R' 0850 240F,178.6E 8.2. :40 6

177.9E 7.3 51 6 1/2

173E 7.4. 10 '7'

"

, .

COMMENTS

- No record

No record

No tsunami

, ,

TRAVEL TIMES OF MAJOR TSUNAMIS

AREA OF ORIGIN: . Kamch~tka .... Kuri1 Is~ GAUGE SITE RECO{¢kq: Tofino,,'." ~=::;.::---------

HOURHRS FROM ~sr.AR, rNIT.WAVE MAX.WAVEYEAR 1'10. DAY CU. T•) LAT. LONG. HAG. DEPTH GAUGE (U. T•) ARR. HT. ARR. HT. PERIOD COMMENTS

SIN 157E

43.2N 145.8E

8/0216 014~ 9R. 0306 14F

2400 2354 6R 4/0350 ZiF'

2331 14/0027 9R 0806 15F

5/0100 . 0042 21R 0347 58R

7/0830, 0807 9R 1655 10F

1918 Sept 7 1716

1923 Feb 3 1602

1923 Apr 13 1531

1952 Nov 4 1658

1958 Nov 6 2258

1959 May 4 0716

1963 Oct 13 0518

1969 Aug 11 2127

1971 Dec 15 0830

1973 Feb 28 0638

1973 June 17 0355

45.5N

54N

56N

52.7N

44.5N

52.5N

44.8N

43.5N

56.0N

151. 5E.

161E'

162.5E

160.3E.

148.5E

159.5E·

149.~E.147.4E

163.3E

8.2

8.3

7.2

8.2 33

8.7 75

8.0 60

8.2' 60

7.8 28

7.8 33

7.6 27

8.0' 48

·9'

8

8'

8

9 i/2

9 1418

9 1/2 12/0700

8 1430

9 1/2' '1325

"':' 3

0630 2

1857 16F

6

No record

No record

No tsunami

No tsunami

TRAVEL TIMES OF MAJOR TSUNAMIS ..- -MEA OF ORIGIN:

r • . ' I:. ~ I, .' ,; ( I_l1ariana __ Japan T~ench__~ GApGE S:l::~E Rf'CO~IDED I .Tofino

HOUR HRS FROM EST,A~~ I~IT.WAVE MAX. WAVEYEAR HO. DAY (U.T.) LAT. LONG. }tAG~ DEPTH. GAUGE (U.!.) ARR. HI. ARR. HT. PERIOD CONMENTS

1896..

June 15 1033 39.6N" 144.2E 7.6

1931 Mar 9 0349 4l.2N 142.5E7.6 . 10 1400 No tsunami

1933 }far 2 1731 39.1N l lf4.7E 8.3 9. 1/2 3/0300 . 0312 .10R 0457 23F

1936 Nov 2 2046 38.2N 142.2E 7.7 80 10 3/0700 No tsunami

1938 .. Nov 5 0843 36.7N ·141. 7E 7.1 33 10·i/2 1900 No tsunami

1938 Nov 5 . 1050 38.2N 141.7E 7.6 100 10 1/2 2130 No tsunami

1938 Nov 6 0854 36.9N 142~ 6E 7.5 - '10 1/2 1930 No tsunami,1952 Mar 4 0123 42.2N . 143. 8E 8.1 45 10 1123 1150 3R 2112 12F

1953 Nov 25 1748 34N . 14l.5E 8.0. 50 10 '1/2 26/0430 . . No records

1960 Mar 20 1707 39.8N ·143.5E 7.5 .60 .10 . 21/0300 No tsunami

1964 . June 16 0402 38.3N 139.2E 7.5 . 57 - . Sea of Japan

1968 May 16 . 0049 40.9N 143.5E 8.2 7 9 1/2 1000 .. 1017 .5R 1625 12F

, 1968 May 16 1039 . 41. 6N 142.9E 7.5 33 9 1/2 2000 Not identifiable overprevious tsunami.

TRAVEL TIMES OF MAJOR TSUNAMIS~ .

AREA OF ORIGIN: Ryukyu - Philippine Trench" GAUGE SITE RECORDED: Tofino" ,

HOUR HRS FROM EST.ARi INIT.WAVE MAX. WAVEMAG. DEPTH

' I

YEAR NO. DAY (U.T.) LAT. LONG. GAUGE (U. T.) ARR. HT. ARR. HT." PERIOD COMMENTS

1911 June ,15 1426 29N 129E 8.7 12 1/2 16/0300

1921 Nov 11 1836 8N- 127E 7.5 14 12/0900 No tsunami

1923 'Sept 1 0259 35.2N 139.5E 8.2 11 1/2 1430 No tsunami

1923 Sept 2 0247 35N 137.5E 7.7 11 1/2 1415 No tsunami

1924 Apr 14 1620 6.5N 126.5E 8.3 15 15/0720 No tsunami

1944 Dec 7 0435 33.7N 136E 8.0 ' 11 1/2 1600 No record

1946 Dec 20 1919 33.0N 135!6E 8.1 11 1/2 21/0700 No tsunami0

1952 Mar 19 1057 9.5N 126.7E 7.7 14 20/0100 No tsunami

1966 Mar 12 1631 24.2N 122.6E' '7.5 48 14 13/0631 No record

1968, Apr 1 0042 32.6N 132.2E 7~7 33 12 1242 No record

1968 Aug 1 2019 16.5N 122.2E 7.7 37 15 2/1100 No tsunami

1972 Jan 25 ' 0206 22.5N 122E 7.7 33 14 1600 No tsunami

1972 Dec 2 0020 6.5N 126.6E 7.7 33 15 1/2 1600, No tsunami

",

~---- ~--~ .• _. "__ w. __ ••• _

TRAVEL TIMES OF MAJOR TSUNAMIS

AREA OF ORIGIN: S, China - Sulu - Celebe~ Seas' GAUGE SITE RECC)RPED: .__T",-,Q"-"f...,.i,,",,,n=o~_~_~ _

HOUR IlRS Fiimx EST .AR. IN1T. WAVE . MAX. WAVEYEAR HO. DAY (U.T•) LAT. tONG. MAG. DEPTH GAUGE (U. T.) ARR. HT. ARR. HT. PERIOD COMMENTS-1897 Sept 20 1906 6N 122E .8.6 17

1918 Aug 15 . 1218 5.5N 123E 8.2 . 16 1/2 16/0500 " No tsunami

1934 Feb 14 0400, 1.7.5N . 119E 7.6 .15 1900 No tsunami

1937 Aug 20 1159 14,5N ' 121.5E 7~5. 15 1/2 21/0300 No tsunami

1948 Jan 24 1747 10.5N 122£- 8,2 15 '1/2 25/0900 No record

1976 Aug 16 1610 7.2N 123,7E 7.8 33 15 1/2 17/0800 No record

."",",.=o_=,!=,,~..•..•••.•..,·1'

h:

!i~

TRAVEL T:hms' OF MAJOR TS1JNAMIS

AREA OF ORIGIN: Java Trench - Banda Sea GAUGE SITE R~CO~)EO; Totino

HOUR ERS FRO~ ~S+~~~. !NIT.WAVE MAX. WAVEYEAR MO. DAY (U.T.) LAT. LONG. MAG. DEPTH GAUGE Jd.T,;) ARlt. HT. MR. HT. PERIOD. COMHENTS

1883 Aug 27 0259 16.7S ·105.4E i7.1/2 Krakatoa Explosion

1938 May 19 1708 IS 120E 7.6. 16 20/0900 No tsunami

1939. Dec 21 '2100 ON 123E 8.0 100'. 16 22/1300 No tsunami

1965 Jan 24 0011 2.4S. 126.0E 7.6 . 6 15 1500 No record

1968 Aug 10 0207 1.4N 126.2E 7.8 33 15 1700 No tsunami

TRAVEL TIMES OF MAJOR TSUNAMIS

AREA OF ORIGIN: N. New Guinea-Bismark ArchipeiagodAUGE SITE: RlI:CO~Dl~D: _T...:;o...:;f;.;;:i;.;;:n,..:..o ------

HOUR HRS FROM EST.AR, INIT,WAVE MAX. WAVEYEAR MO. DAY (U.T.) LAT. LONG. MAG. DEPTH GAUGE (U ~ T.) ARR. HT, ARR. HT. PERIOD

1914 May . 26 1423 28 137E 7.9 15 1/2

1935 Sept 20 0147 3.5S 141.8E 7~9 33 . 15 1700

. ,

""

COJ:.fMENTS

No tsunami

J";1~:c;rio\~~._---------_._--- __. . ~._._.~.. ._ ..._, w._..·_.__ ._._·__··_··_ ..__·_..

TRAVEL TIMES OF MAJOR TSDNA}fIS

AAEA OF ORIGINi Solomon Sea - New Hebrides ' GAUGB S11'~ RECORDED! Tofino

HOUR HRS }~OM Est.AR~ INrT.WAVE MAX.WAVE, YEAR MO. DAY (D.T.) LAT. LONG. MAG. DEPTH GAUGE l.U.T.) ARR. HT. ARR. HT. PERIOD' COMMENTS- e d

1919 May 6 1941 :is 154E 8.1 1l~ 1/2 7/0600 ' No record

1920 Feb 2 1122 6.58 150E ,,' 7.8 15 1/2 3/0300 ,No tsunami

1931 Oct' 3 1913 10.5S 16L8E 7.9 14 1/2 4/1000 0952 ,2R 1313' 6F

1934, July 18 1940 138 '166.5E 8.2 13 1/2 19/0900 No tsunami

1939 Jan 30 0218 6.5S 155.5E 7.8 33 14 1/2 1700 -- No tsunami

1939 Apr 30 0256 9.05 159.5E. 8~0 rso. 14 1/2 '1700 No tsunami

1949 Oct 19 2100 6.58 154E 7.5 ' 60 14 1/2 20/1100 No tsunami.1953 Apr 23 1624 45 154E 7.5 14,1/2 24/0700 No record

1966 Jun~ 15 0132 10.38 160. SE, 7.6 ' 23, 14 1/2 1600, No record

1966 pee 31 1823 11.88 16?5E '7.7 56 14 1/0800 No record

, 19i1 July 14 0611 5.58 153.9E 7.9 4i ' 1,5 2106 No record

1971 July 26 0123 4,98 ,153.2E 8.4 48 15 1600 No record, ,

14 1/2 21/05001975 July 20 1437 6.5S 154.9E 7.7 49 'No tsunami

, I

'\.

• ••.._._-, •.-._._-_...__"'lfI"" ..,,~.,.---.

AREA OF ORIGIN: ~T~a~s~m~a~n~S~e~a~ ~

COMMENTS

No tsunami

No tsunami

19 .2100

16 1/2 17/1500 .

.: TRAVEL TIMES OF MAJOR TSUNAMIS

~AUG~ si~:~ ~~c6¥Pf~; -=-T:.::;o..:::.f=in=,o~ _

HRS FRO}! ~S1'.M, INIT,WAVE MAX.WAVELONG. HAG. im:p±H GAUGE. CO. T.) . ARR. liT. ARR. liT. PERIOD

157E 7.8 .

172.2E 7.6

HOURYEAR MO. DAY CU. T ~ ) LAT.

1924 June 26 0138 568

1929 June 16 2248 41. 8S

--------_._.....-._._-_._-_.....__._- --'-'---'---.-._..

,. <-.~ ,....~'~.,.:::;: ..~:::::-.::.;~_.~'.6,,;;I,'!""'~ ...i:-~,'1

AREA OF ORIGIN: Kermadec - Tonga Trench

'.

TRAVEL TIMES OF MAJOR TSUNAMIS

GAUGE SITE RECORbp:p: _.T....:;.o....:;.f.::,in:.:.o::..-- _

AREA OF ORIGIN: --=H.:::.aw~a::.:i==i=-- _

I

PERIODHOUR

YEAR MO. DAY (U.T.) LAT.

TRAVEL TIMES OF MAJOR TSUNAMIS

GAUGE SIT~ RECORDED: Tofino-=-===;;:.;:....--------nRS FROM Est.AR, INIT.WAvE MAX.WAVE

LONG. MAG. DEPTH GAUGE CU. T. ) AllR. HT. ARR. HT. COMMENTS

1975 Nov 29 1448 19. 4N 155.1W. 7.2 .. 5 1/2 2018. ·2056 3R' 22029F

"..

'M' __·_"_,'._.__• ~_"""_'" " __'~._"'.'''.' ,_, •