CHILE
EARTHQUAKE AND TSUNAMI OF 22 MAY 1960
George Pararas-Carayannis
(Excerpts
from archives compiled in preparaation of a Catalog of Tsunamis
in the Pacific Ocean and for the Catalog of Tsunamis in the Hawaiian
Islands. World Data Center A- Tsunami U.S. Dept. of Commerce
Environmental Science Service Administration Coast and Geodetic
Survey, May 1969)
 Summary
The largest earthquake ( magnitude
9.5) of the 20th century occurred on May 22, 1960 off the coast
of South Central Chile. It generated one of the most destructive Pacific-wide
tsunamis. Near the generating area, both the earthquake and the tsunami were extremely destructive,
particularly in the coastal area extending from Concepcion to
the south end of Isla Chiloe. The most extensive tsunami damage
occurred at Isla Chiloe, the coastal area closest to the epicenter.
Huge tsunami waves measuring as high as 25 meters, arrived within
10 to 15 minutes after the earthquake, killing at least two hundred
people, sinking all the boats, and inundating half a kilometer
inland. There was extensive damage and loss of life at Concepcion,
Chile's top industrial city. Near the city of Valdivia, the earthquake
and subsequent aftershocks generated landslides which killed
18 people. At the port city of Valparaiso, a city of 200,000,
numerous buildings collapsed. A total of 130,000 houses were
destroyed - one in every three in the earthquake zone and approximately
2,000,000 people were left homeless. Total damage losses, including
to agriculture and to industry, were estimated to be over a half
billion dollars (1960 dollars). The total number of fatalities
associated with both the tsunami and the earthquake was never
established accurately for the region. Estimates of fatalities
ranged between 490 to 5,7002 with no distinction as to how many
deaths were caused by the earthquake and how many were caused
by the tsunami However, it is believed that most of the deaths
in Chile were caused by the tsunami.
Parking meters along
the Hilo Bay front were bent from the tremendous force of the
tsunami waves. ITIC Archives - U.S. Army Corps of Engineers Photo).
The tsunami was also very destructive
throughout the Pacific Ocean, but particularly in the Hawaiian
Islands and in Japan where there was tremendous loss of life
and damage to property. It took about 15 hours for the tsunami to travel to the Hawaiian
Islands - a total distance of more than 10,000 kilometers from
the generating area in Southern Chile. The tsunami caused little
damage in most of the Hawaiian islands, but the island of Hawaii
and particularly the Hilo Bay area were hit the hardest. Destructive waves destroyed completely the waterfront
and killed 61 people. Total damage was estimated at $24 million
(1960 dollars).
Elsewhere along the
western coast of the United States, notable tsunami waves and
run-up were begun 15.5 hours after the occurrence of the earthquake
in Chile. At Crescent City, California, waves of up to 1.7 meters
were observed and minor damage was reported.
Introduction
On May 22, 1960, the
largest recorded earthquake this century occured off the coast
of South Central Chile along the Peru-Chile Trench. The earthquake
generated one of the the most destructive tsunamis in the Pacific.
Both the earthquake and the tsunami were extremely destructive
in Chile, particularly in the coastal area extending from Concepcion
to the south end of Isla Chiloe. The destructive effects of the
tsunami were experienced throughout the Pacific Ocean and were
particularly devastating in Chile, Hawaii, and Japan.
 The May 22, 1960 Chilean
Earthquake
The May 22, 1960 earthquake
occurred at 19:11 GMT, off the coast of South Central Chile.
Its surface-wave magnitude was 8.6. The Moment Magnitude (a better
measure of the earthquake's energy release)was estimated at 9.5.
The epicenter of the earthquake was at 39.5° South, 74.5°
West, and the focal depth was 33 kms (20.5 miles).
Earthquake
Effects in Chile
A number of large
foreshocks proceeded the main earthquake by about 30 minutes.
The large foreshocks served as a warning and some lives were
saved as many people had evacuated buildings and had taken to
the safety of open space.
The earthquake was
extremely destructive in Chile, particularly along the coastal
area extending from Concepcion to the south end of Isla Chiloe.
There was extensive damage and loss of life at Concepcion, Chile's
top industrial city. Near the city of Valdivia, the earthquake
and subsequent aftershocks generated landslides which killed
18 people. At the port city of Valparaiso, a city of 200,000,
numerous buildings collapsed.
Estimates of Fatalities
and Property Damage: The number of fatalities associated with
both the tsunami and the earthquake was never established accurately
for the region. Estimates of fatalities ranged between 490 to
2,290, with no distinction as to how many of the deaths were
caused by the earthquake and how many were caused by the tsunami
waves. However, it is believed that most of the deaths were caused
by the tsunami, while most of the property damage may have been
caused by the earthquake.
A total of 130,000
houses were destroyed - one in every three in the earthquake
zone. Total damage losses, including to agriculture and to industry,
were estimated to be over a half billion dollars (1960 dollars).
Source Mechanism
of the May 22, 1960 Earthquake
This southern region
of Chile where the May 22, 1960 earthquake occured was along
the great subduction zone between the Nazca oceanic plate and
the South American continental plate. Specifically, the earthquake's
focal mechanism was of the thrust-type and was caused by the
downward movement of the subducting Chile Ridge oceanic plate
below the South American plate. This coincided with the Chile
triple junction region where elastic strain had accumulated.
Earthquake Magnitude: The Great Chilean earthquake of May 22, 1960,
was the largest seismic event ever recorded instrumentally in
the world. The earthquake's moment magnitude (MW) was a staggering
9.5. The energy released was about one fourth of the total global
seismic moment release between the years 1904-1986.
Foreshoks, the Main
Earthquake and Major Aftershocks: There
were several large foreshocks in the general area which proceeded
the main earthquake of 19:11 GMT, on May 22, 1960. The aftershocks
continued for weeks. The epicenters of these aftershocks extended
from Latitude 37 degrees South to as much as 48 degrees South
and from Longitude 71.5 degrees West to 77.0 West.
Fault Length: The extensive distribution of
the afterschoks indicates a rather extensive fault zone which
was almost 1,000 km long 300 km wide.
The
May 22, 1960 Chilean Tsunami
 Tsunami Effects along the Peru - Chile
Coast
The great May 22,
1960 earthquake in Chile generated a catastrophic, Pacific-wide
tsunami. Locally, in Chile, the tsunami affected more seriously
an area extending from Concepcion to the south end of Isla Chiloe.
At the coastal area closest to the epicenter, huge tsunami waves
measuring as high as 25 meters (up to 82 feet), arrived within
10 to 15 minutes after the earthquake, killing at least two hundred
people, sinking all the boats, and inundating half a kilometer
inland. Death estimates from the tsunami for the entire Peru-Chile
coastline ranged from 330 to 2000 persons.
The most extensive
tsunami damage in Chile was reported from Isla Chiloe. Two hundred
deaths were reported here from the tsunami. The inhabitants,
fearing the earthquake, took to small boats to escape the shaking.
The trough of the tsunami arrived just 10 to 15 minutes after
the earthquake, along more than 500 m of the coast. Upon the
return of the sea in a thunderous breaker, all boats were lost.
Aerial view of coastal
area on Isla Chiloe, Chile, showing tsunami damage. From Archives
of ITIC; Source Unknown)
Other areas along
the South American coast were adversely impacted . The total
number of lives lost from the tsunami along the coast Peru-Chile
coast is not known with accuracy but estimates range anywhere
from 330 to 2000 people. Waves as high as 25m were reported.
The
Great Pacific-Wide Tsunami of 22 May 1960
The Chilean earthquake
of May 22, 1960, generated a large Pacific-wide tsunami which
raced across the ocean causing extensive destruction along its
path, particularly in Hawaii and in Japan. The number of fatalities
attributed to both the tsunami and the earthquake in Chile have
been estimated to be between 490 to 2,290. Damage costs were
estimated at over half billion dollars(1960 dollars).
 The Effects of the
May 22, 1960 Tsunami in the Hawaiian Islands
The great Pacific-wide
tsunami traveled a total distance of more than 6,000 miles (10,000
kilometers) from the the generating area in Southern Chile before
reaching the Hawaiian Islands. Travel time was about 15 hours
after the earthquake. The local date in Hawaii was 23 May 1960.
The tsunami caused little damage in most of the Hawaiian islands,
but the island of Hawaii and particularly the Hilo Bay area were
hit the hardest. Damage costs were estimated at $24 million.
61 people lost their lives.
Island of Hawaii
Hilo: The island of Hawaii was the first of the Hawaiian
islands to experience the effects of the tsunami. The first of
a series of eight destructive waves arrived at Hilo Bay, 14.8
hours after the earthquake. Subsequently, at 12 to 20 minute
time intervals, seven more large waves arrived. The maximum tsunami
runup at Hilo Bay was 10.7 meters (about 35 feet) above sea level.
Elsewhere, the runup ranged from 3-17 feet.
 Hardest
hit was the Waiakea area of Hilo. The waves advanced far inland
and destroyed much of the downtown area of Hilo. The water washed
as far inland as Kilauea Avenue/Keawe Street through the entire
present downtown area and to Kekuanaoa Street near Kilauea Avenue.
Only a few buildings remained standing. These were generally
buildings made with reinforced concrete or structural steel or
some that were sheltered by these buildings. However, even these
buildings in the dowtown area were severy gutted by the force
of the waves. Frame buildings either were crushed or carried
inland or out to sea. Debris-carrying tsunami waves bent parking
meters around telephone polls in downtown Hilo.
(Honolulu Advertiser
photo of tsunami devastation in the downtown area of Hilo, Hawaii)
A total of 61 people
were killed and about 540 homes and businesses were destroyed
or severely damaged. Damage was estimated at $24 million (in
1960 dollars). Many of the deaths in Hilo occured in the Waiakea
peninsula area which was considered relatively safe because it
had experienced minimal damage during the 1946 tsunami.
The Effects
of the May 22, 1960 Tsunami in California
Elsewhere along the
western coast of the United States, Crescent City, California,
experienced notable tsunami waves and run-up. The tsunami travel
time of the first wave to arrive at Crescent City, was 15.5 hours
after the occurrence of the earthquake in Chile. At Crescent
City, tsunami waves of up to 1.7 meters (appr. 5.6 feet) were
observed and minor damage was reported.
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