Hawaiian Volcano Observatory
skip past main content navigational bar yellow horizontal separator line


yellow horizontal separator line

Mauna Loa

yellow horizontal separator line

bullet - no meaningCurrent

bullet - no meaningFelt EQs
bullet - no meaningDestructive

bullet - no meaningSeismicity
bullet - no meaningInstruments

yellow horizontal separator line

Other Volcanoes

yellow horizontal separator line

Volcanic Hazards

yellow horizontal separator line

About HVO

yellow horizontal separator line


Hazards in Hawai`i

House destroyed by earthquake
House destroyed by earthquake in Kalapana on June 25, 1989
Seismic hazards are those related to ground shaking. Landslides, ground cracks, rockfalls, tsunami - these are all seismic hazards. Generally, though, we think more in terms of damage to our structures and our possessions.

Engineers, seismologists, architects, and planners have carefully evaluated seismic hazards related to building construction. They have devised a system of classifying seismic hazards on the basis of the expected strength of ground shaking and the probability of the shaking actually occurring within a specified time. The results are included in the Uniform Building Code (UBC) seismic provisions.

The UBC seismic provisions 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). The shaking is quantified in terms of g-force (familiar to race car drivers and astronauts), the earth's gravitational acceleration. The diagram below is a way of describing seismic zonation.

UBC seismic zones

Zonation Based on General Principles

In 1992, the USGS was asked to reevaluate the seismic hazards in Hawai`i County. A probabilistic seismic-hazards assessment was carried out according to previously established procedures.

Seismic-hazards analysis combines:

  • Earthquake rates known from the historical record
  • Information about how strong ground shaking dissipates with increasing distance from the earthquake
  • Determination of the probabilities that specified levels of ground motion will occur in a specified time period
The new calculations indicate that Hawai`i County has a greater chance of strong ground shaking than was previously thought.

JurisdictionIsland 1988 Zone 1997
County of Hawai`i Hawai`i 3 4
County of Maui Maui 2B 2B
Kaho`olawe 2B 2B
Lana`i 2B 2B
Moloka`i 2B 2B
City & County of Honolulu O`ahu 1 2A
County of Kaua`i Kaua`i 1 1
Ni`ihau 1 1

Hawai`i Seismic Zone Assignments, 1988 and 1997

Map showing seismic zone assignments for the Hawai`i

Map of the 1997 Hawai`i Seismic Zone Assignments

For an overview of seismic hazards in Hawai`i, see the online USGS publication, Volcanic and Seismic Hazards on the Island of Hawai`i, reprinted in 1997.

skip past bottom navigational bar

Homeblank spacerVolcano Watchblank spacerProductsblank spacerGalleryblank spacerPress Releases
How Hawaiian Volcanoes Work

The URL of this page is http://hvo.wr.usgs.gov/earthquakes/hazards/
Contact: hvowebmaster@usgs.gov
Updated: 18 June 2001 (pnf)