ANATOMY OF TSUNAMIS:A COMPILATION OF

HISTORICAL TSUNAMI MAREOGRAMS

Yohko Igarashi 1, Laura Kong 2, Masahiro Yamamoto 3

1. ITIC; now with Japan Meteorological Agency, 2. ITIC, UNESCO/IOC-NOAA, USA, 3. IOC/UNESCO, France

Enhancing understanding towards the development of Tsunami Warning Systems

• Various tsunami wave forms from local/regional and small/large tsunami

• UNESCO/IOC/ITIC have compiled tsunami records.

• TWC staff must interpret quickly• Lack of educational materialsTsunami interpretationTimelines of actions taken by TWCSummary of the lessons learned

• 1946 Aleutian Islands, 1960 Chile, 1975 Hawaii, 1998 Papua New Guinea, 2004 Sumatra, 2006 Kuril Islands, 2007 Solomon Islands and Peru events are compiled.

2006 November 15, Kuril Tsunami• Mw 8.3: east of Kuril Islands. • NW Pacific Tsunami Advisory Center

(JMA) issued. • PTWC issued the regional warnings. • One person: injured in Waikiki, Hawaii, by

34 cm tsunami at Honolulu. • Damages at Crescent City, California (176

cm)• Large & shorter period tsunami in Japan

about 4-5 hours after the first wave.

Malokurilsk & Petropavlovsk Ayukawa, Mera, Omaezaki Hanasaki, Hachinohe, Ofunato Miyake, Muroto, Tosashimizu

Numerical simulation(after Met. Res. Inst. JMA)

Central &SW Pacific S-America Peru & Chile

Peru (August 15, 2007)

• Mw 8.0: near the coast of central Peru.

• 514 killed by EQ.

• 3 killed: a sparsely populated desert area

• Largest tsunami runup heights (10 m) and massive inundation distances up to 2 km.

• PTWC issued Warnings.

Start the regional cooperation in SE Pacific countries

DART32401 Chilean stationsonly 5 cm

Hilo,Kawaihae, Kahului,

Honolulu, Nawiliwili (Hawaii) Japanese stations and Midway

Solomon (April 1, 2007)

• Mw 8.1 (USGS) occurred on April 1

• This earthquake generated tsunami

• More than 50 people killed.

• 10 m high tsunami at near the source.

• The nearest sea level station (Honiara) record 21cm tsunami (345 km away).

Need dense sea level network

South Pacific North Pacific

Maximum wave height distribution(after NOAA/PMEL)

Historical Tsunami Records

• Many observed tsunami waveform data on the web sites, ITIC Newsletters and ERI-JMA CD-ROMs: all Japanese

tsunami data from 1899 to 1996 (by ERI and JMA).

• Some web sites have raw data & figures• Some station data are kept in two or more

organizations.

Eastern Aleutian Islands (April 1, 1946)

• The earthquake with Mw 8.1 occurred on April 1, 1946.

• The abnormally large tsunami was observed compared with the earthquake magnitude; “tsunami earthquake”.

• The tsunami hit Unimak Island; the run-up reached 35m.

• Tsunami hit the Hawaiian Islands where 159 people were killed. Some places;higher than 16m.

West coast of North America

California, US

Hanasaki, Miyako and Ayukawa, Japan

• 10 m tsunami; Juan Fernandez off Chile and Marquesas Is in French Polynesia.

• Tsunami heights observed along California were nearly 1 m. However, certain locations recorded larger tsunamis, such as 4 m at Princeton& Half Moon Bay, 3 m at Muir Beach.

• Tsunamis observed along the Pacific coast of Japan, west from the source, were 0.5 m at most.

• USA NTWC was established in 1948

Hawaii (November 29, 1975)• Mw 7.2: early morning off the Hawaiian Is.• Sea began slowly rising within 10-30

seconds after ground shaking and then rapidly developed into a rushing wave.

• The first wave:1.5m. Second wave: 8 m, and the highest wave reached 15 m.

• Killed 2 campers, 19 campers were injured.

• Hilo: 20 min. Honolulu: 49 min. • Small tsunami: Alaska, California, Japan.

Sea level stations, Hawaii

Hilo, Kahului, Honolulu and Nawiliwili, Hawaii

Miyako, Ayukawa, Miyakejima, Owasw, Murotomisaki, Japan

Papua New Guinea (Jul.17, 1998)

• Mw7.0 EQ: near the north coast of PNG.

• Trigger: large underwater landslide

• Destructive tsunami was generated.

• More than 2000 people were killed

• Maximum height: 15 meters.

• Destructive tsunami: only local areas.

• Along Japanese coasts: 10 ~ 20cm

• No tsunami records at the other sea level gauges such as Yap or Malakal.

Ayukawa, Mera, Miyakejima, Chichijima, Uragami, Murotomisaki, Tanegashima, Ishigakijima, Japan