Introduction - Tsunami - page 13

Table 1.4 Causes of tsunami in the Pacific and eastern Indian Ocean Regions over the last 2000 years
Cause Number of events Percentage of events Number of deaths Percentage of deaths
Landslides 66 4.4 14,661 2.0
Earthquakes 1,242 83.0 644,880 90.0
Volcanic 67 4.5 51,643 7.2
Unknown 122 8.1 5,364 0.7
Total 1,497 100.0 716,548 100.0
Source Intergovernmental Oceanographic Commission ( 1999a , b ), United Nations ( 2006 ), National Geophysical Data Center ( 2013 )

a small earthquake on the ocean floor, 120 km southeast of
the city of Kamaishi, sent a 30 m wall of water crashing
into the coastline, killing 27,122 people. The same tsunami
event was measured 10.5 h later in San Francisco on the
other side of the Pacific Ocean. On March 3, 1933, disaster
struck again when a similarly positioned earthquake sent
ashore a wave that killed 3,000 inhabitants. Then, this same
coast was hit by one of the biggest tsunami in recorded
history, the T ¯hoku event, on March 11, 2011. Estimates of
the dead range from 18,539 to 23,295. The maximum run-
up was 38.9 m. Deadly tsunami also characterize the South
China

Table 1.5 Largest known death tolls from tsunami in the Pacific and
Indian Oceans over the last 2000 years
Date Fatalities Location
26 December 2004 228,432 Indonesia-Indian Ocean
22 May 1782 50,000 Taiwan
27 August 1883 36,417 Krakatau, Indonesia
28 October 1707 30,000 Nankaido, Japan
15 June 1896 27,122 Sanriku,Japan
20 September 1498 26,000 Nankaido, Japan
13 August 1868 25,674 Arica, Chile
11 March 2013 23,295 Sendai, Japan*
27 May 1293 23,024 Sagami Bay, Japan
4 February 1976 22,778 Guatemala
29 October 1746 18,000 Lima, Peru
21 January 1917 15,000 Bali, Indonesia
21 May 1792 14,524 Unzen, Ariake Sea, Japan
24 April 1771 13,486 Ryukyu Archipelago
22 November 1815 10,253 Bali, Indonesia
May 1765 10,000 Guanzhou, South China Sea
11 August 1976 8,000 Moro Gulf, Philippines
Source Intergovernmental Oceanographic Commission ( 1999a , b ) and
National Geophysical Data Center ( 2013 )
*Note Other internet sources quote a lower figure of 18539

Sea. Here, recorded tsunami have killed 77,105

people, mainly in two events in 1762 and 1782.

1.5.4 New Zealand and Australia

Australia and New Zealand are not well represented in any
global tsunami database. This is surprising for New Zea-
land, because it is subject to considerable local tectonic
activity and lies exposed to Pacific-wide events. At least
thirty-two tsunami have been recorded in this latter country
since 1840 (de Lange and Healy 1986 ). The largest event
occurred on January 23, 1855 following the Wellington
earthquake. The run-up was 9-10 m high within Cook Strait
and 3 m high at New Plymouth, 300 km away along the
open west coast. However, the highest recorded tsunami
occurred following the Napier earthquake of February 2,
1931. The earthquake triggered a rotational slump in the
Waikare estuary that swept water 15.2 m above sea level.
The most extensive tsunami followed the August 13, 1868
Arica earthquake in northern Chile. Run-up heights of
1.2-1.8 m were typical along the complete east coast of the
islands. At several locations, water levels dropped 4.5 m
before rising an equivalent amount. Subsequent earthquakes
in Chile in 1877 and 1960 also produced widespread effects.
New Zealand has the distinction of recording two tsunami
generated by submarine mud volcanism associated with
diapiric intrusions. These occurred near Poverty Bay on the
east coast of the North Island. The largest wave had a run-
up of 10 m elevation.

Gulf, Philippines, on August 16, 1976, where 8,000 people
died. The largest, total death toll is concentrated in Indo-
nesia where 237,156 deaths have occurred, the two largest
events being the Indian Ocean Tsunami of 2004 (167,736
deaths) and the eruption of Krakatau (36,000 fatalities).
This location is followed closely by the Japanese Islands
where 234,595 fatalities have occurred. Two events affected
the Nankaido region of Japan on October 28, 1707 and
September 20, 1498, killing 30,000 and 26,000 people
respectively. The Sanriku coast of Japan has the misfortune
of being the heaviest populated tsunami-prone coast in the
world. About once per century, killer tsunami have swept
this coastline, with two events striking within a forty-year
time span between 1896 and 1933. On June 15, 1896,