September 6, 1996

A weekly feature provided by scientists at the Hawaiian Volcano Observatory.

Geologic Hazards

The primary mission of the Hawaiian Volcano Observatory (HVO) is to evaluate earthquake and volcanic hazards and provide timely information to the various State and County officials responsible for emergency preparedness and response.

In an effort to improve communications during times of crisis, HVO administrators conferred last week with representatives from the Department of Defense Intelligence Systems Support Office, the State Department of Defense/Civil Defense Emergency Operations Center (EOC), Hawaii County Civil Defense, the National Park Service, and the Pacific Disaster Center (PDC). Negotiations are underway for installation of a circuit linking HVO to the PDC/EOC Emergency Communication Network. The link will allow immediate sharing of information and provide for consultation and briefings via video-conferencing.

Living with, and responding to, geologic hazards is an inescapable part of life. The current eruption of Kilauea Volcano, for example, has covered over 36.5 square miles of land with fresh lava, destroyed 181 homes, 6 community structures, and 8 miles of highway. Economic losses since the start of the eruption in 1983 top $61 million. At present, there has been one fatality associated with the eruption.

Hawaiian volcanoes also produce thousands of earthquakes each year. Most are so small that they can be detected only by sensitive seismic instruments, but damaging quakes do occur. A magnitude 6.6 earthquake rocked the Big Island in 1983 and caused an estimated $7 million in damage to structures in Ka'u, Puna, and North and South Hilo. Fortunately, there were only minor injuries to residents.

Occasionally, Hawaiian earthquakes generate local tsunamis that inundate coastal areas. The 1975 magnitude 7.2 earthquake on Kilauea's south flank caused a tsunami that claimed two lives and damaged much of the Kalapana coastline.

Lava flows, earthquakes, and tsunamis can not be stopped or prevented. These hazards can be anticipated, however, and the risks substantially diminished as scientists and emergency managers come together through effective communication and prompt action.

Eruption Status

The current eruption of Kilauea continued unabated this week with lava entering the ocean in Hawaii Volcanoes National Park. There were no felt earthquakes last week.