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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)
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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