Geoscience Reference
In-Depth Information
Table 1.2
Origin of tsunami by region around the Pacific Ocean
(a)
Region
Number of tsunami
generated
Percentage
60°
Japan
329
25.2
40°
South America
278
21.3
20°
New Guinea-Solomon
Islands
129
9.9
0°
Philippines
128
9.8
-20°
Kamchatka-Kuril Islands
95
7.3
New Zealand-Tonga
82
6.3
-40°
North America
78
6.0
-60°
Alaska-Aleutian Islands
77
5.9
90°
150°
-150°
-90°
Central America
72
5.5
Longitude
Hawaii
39
3.0
Total
1,307
100.0
(b)
Source
Based
on
Intergovernmental
Oceanographic
Commission
60°
(
1999a
,
b
)
40°
The most tsunamigenic coastline in the world is that of
the Kamchatka Peninsula, Russia (Gusiakov and Osipova
1993
). Between 1737 and 1990, the region experienced
almost 8,000 earthquakes of which 96 generated localized
tsunami. Volcanic eruptions here have also produced six
tsunami, while four events have an unknown source. During
the same period, the region was subject to 15 tsunami from
distant sources. A significant tsunami floods alluvium plains
along the peninsula every 12.3 years (Pinegina et al.
1996
).
The most destructive tsunami, penetrating up to 10 km
inland, occurred in 1737, 1841, 1923, 1937, 1952, and 1969.
The largest event followed the Great Kamchatka Earth-
quake of October 17, 1737. Tsunami run-up heights reached
60 m above sea level in the North Kurile Islands. The
second largest event occurred on November 4, 1952, with
run-up heights of 20 m in the same area. This latter tsunami
was also a Pacific-wide event.
Local tsunami are also common on the islands of the
South Pacific (Howorth
1999
); however, no significantly
sized, earthquake-induced tsunami has propagated outside
this region. Because many islands drop off into deep water
locally generated tsunami can travel at their maximum
velocity, up to 1,000 km hr
-1
, and reach the adjacent shore
in 5-10 min. The Papua New Guinea-Solomon Islands
region has experienced 78 tsunami in the period between
1768 and 1983. Volcanism has caused one-eighth of all
tsunami. The largest event occurred on March 13, 1888,
when the Ritter Island volcano off the north coast of Papua
New Guinea collapsed, generating a 15 m high tsunami.
The most recent event of significance occurred in the early
evening of July 17, 1998 along the Sissano-Aitape coast of
northern Papua New Guinea (Davies et al.
2003
). One of the
stories earlier referred to this event. It will be described in
20°
0°
-20°
-40°
-60°
90°
150°
-150°
-90°
Longitude
Fig. 1.2
Location of tsunami in the Pacific Ocean region: a Location
of 1,274 tsunami between 47 BC and the end of the 20th century. Size
of circle increases proportional to number of events per degree square
of latitude and longitude. b Source of significant distant (teleseismic)
tsunami. Size of circle increases proportional to area affected and
magnitude
of
the
event.
Based
upon
Lockridge
(
1985
,
1988
),
Intergovernmental Oceanographic Commission (
1999a
)
frequency in the 20th century. Earthquakes in southern
Chile, Alaska, and the Kamchatka Peninsula have the
greatest chance of generating ocean-wide tsunami in the
Pacific. The west coast of the United States provides a
fourth source; however, the last Pacific-wide event origi-
nating here occurred 300 years ago, before European set-
tlement, on January 26, 1700 (Satake et al.
1996
). The May
22, 1960 Chilean event is the most significant historical
tsunami (Myles
1985
; Pararas-Carayannis
1998
). This event
tsunami in the 20th century. A series of tsunami waves
spread across the Pacific over a period of 24 h, taking over
2,500 lives. The tsunami significantly affected such diverse
places
as
Hawaii,
Pitcairn
Island,
New
Guinea,
New
Zealand, Japan, Okinawa, and the Philippines.
