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What are my risks?
Seismic Hazard Zones in Hawaii
County
Potential
for damage from strong earthquakes cannot be avoided on the Big
Island. Damage can be reduced by land-use zoning that restricts
building on or near steep slopes that can fail during an earthquake
and in areas underlain by materials that are likely to amplify the
ground motion of a strong earthquake. Because of the history of
seismicity on the Island of Hawaii, the County has adopted the recommendations
to upgrade their seismic hazard ranking to 4 based on the 1997 Uniform
Building Code. The UBC contain six seismic zones, ranging from 0
(no chance of severe ground shaking) to 4 (10% chance of severe
shaking in a 50-year interval).
For more
information about Seismic Hazards in Hawaii click
here.
Map of Hawaii County Earthquakes
(1929-1994)
Click
here to download an image map of Hawaii County earthquakes.
History of Earthquakes in Hawaii
County
Each year
thousands of earthquakes occur in Hawaii, with the majority of them
too small to be felt except by highly sensitive instruments. The
movement of molten rock within Kilauea or Mauna Loa causes the majority
of Big Island earthquakes.
Big Island
earthquakes of magnitude 6 or greater tend to occur in clusters
with reoccurrence intervals of 10-12 years. Two regions on the Big
Island have the potential for a large earthquakes: East Kona and
South Kona.
The largest
Hawaiian earthquake in recorded history occurred in 1868 beneath
the Ka'u district on the southeast flank of Mauna Loa. The 7.5-8.1
magnitude caused damage across the entire island of Hawaii and could
be felt as far away as Kauai. The earthquake caused a mudflow that
killed 31 people and coastal subsidence produced a tsunami that
destroyed several villages on the Ka'u-Puna coast and drowned 46
people.
The second
most destructive earthquake in Hawaii was occurred on Kilauea's
south flank in Kalapana, November 29, 1975. Damage to lives and
property from the 7.2 magnitude earthquake was relatively small
due to the sparse population of the region. The earthquake caused
11 feet of the Kalapana coast to subside, triggering a tsunami.
The tsunami took the lives of two campers at the Halape Campgrounds
in Ka'u.
History of Earthquakes in Hawaii, M6 and Greater,
1868-Present
|
Year
|
Date
|
Magnitude
|
Source
|
|
1868
|
Mar
28
|
6.5-7.0
|
Mauna
Loa south flank |
|
1868
|
Apr
2
|
7.5-8.1
|
Mauna
Loa south flank |
|
1918
|
Nov
2
|
6.2
|
Ka'oki,
between Mauna Loa and Kilauea |
|
1919
|
Sep
14
|
6.1
|
Ka'u
District. Mauna Loa south flank |
|
1926
|
Mar
19
|
>6.0
|
NW of
Hawai'i Island |
|
1927
|
Mar
20
|
6.0
|
NE of
Hawaii Island |
|
1929
|
Sep
25
|
6.1
|
Hualalai
|
|
1929
|
Oct
5
|
6.5
|
Hualalai
|
|
1938
|
Jan
22
|
6.9
|
N of
Maui |
|
1940
|
Jun
16
|
6.0
|
N of
Hawaii Island |
|
1941
|
Sep
25
|
6.0
|
Ka'oki |
|
1950
|
May
29
|
6.4
|
Kona |
|
1951
|
Apr
22
Aug 21
|
6.3
6.9
|
Lithospheric |
|
1952
|
May
23
|
6.0
|
Kona |
|
1954
|
Mar
30
|
6.5
|
Kilauea
south flank |
|
1955
|
Aug
14
|
6.0
|
Lithospheric |
|
1962
|
Jun
27
|
6.1
|
Ka'oki |
|
1973
|
Apr
26
|
6.3
|
Lithospheric |
|
1975
|
Nov
29
|
7.2
|
Kilauea
south flank |
|
1983
|
Nov
16
|
6.6
|
Ka'oki |
|
1989
|
Jun
25
|
6.1
|
Kilauea
south flank |
Source: Atlas of Hawaii, Third Edition, 1998
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