While the five most severe tsunamis to hit here in the past 60 years have come from three areas — Chile, Russia's Kamchatka region, Alaska and the Aleutian Islands — Hawai'i is at risk from almost every point of the compass.

Emergency preparedness officials maintain that no Hawaiian shoreline is safe from a tsunami. And just because a tsunami hasn't hit Waikiki or Wai'anae in a century or more is no reason to feel secure there.

"If it's a sheer cliff at least 50 feet high and you've got your house up there, you're probably all right," said Daniel A. Walker, retired University of Hawai'i seismologist and O'ahu Civil Defense tsunami adviser.

Otherwise, you should have a tsunami evacuation plan. The Dec. 26, 2004, Indian Ocean tsunami, that killed or left missing more than 220,000 people in 11 countries, underscored that.

"It was a wake-up call. It rattled our cage," Walker said.

Hawai'i's disaster-management experts are now taking a fresh look at quake zones in areas that have not traditionally generated Pacific-wide events.

"The issue of a large event in the southwest Pacific or the western Pacific is something we are addressing as we speak," Walker said.

Charles "Chip" McCreery, director of the Pacific Tsunami Warning Center, said those regions include the area around Japan and the region from Tonga to the Solomon Islands and Papua New Guinea. He said he also is keeping an eye on the West Coast from Northern California to British Columbia.

"Every 300 to 500 years, there's a major earthquake there (along the West Coast). The next time that pops off, it will be a big problem for those areas, but the tsunami will hit Hawai'i," he said.

With seismically active zones rimming the Pacific Ocean, McCreery said, "We're probably at risk from anyplace."

Tsunamis that have caused damage in the Islands in recent generations have come from the Aleutians (1946 and 1957), Kamchatka (1952), Chile (1960) and Alaska (1964), and from an earthquake near Kalapana on the Big Island (1975). A 1994 earthquake in Japan's Kuril Islands prompted a statewide coastal evacuation in Hawai'i, but the wave measured only a few inches locally.

Hawai'i's tsunami experts meet regularly at O'ahu Civil Defense offices, where they're working to anticipate the next tsunami by studying seismic scenarios. They're also reviewing problems that hampered the response to the Indian Ocean tsunami, the Civil Defense response to Hurricane Katrina and a confusing tsunami warning last June in California.

On June 14 last year, a quake of about 7.4 magnitude shook at 7:51 a.m. off Northern California. Within minutes, the Alaska-based West Coast/Alaska Tsunami Warning Center issued a tsunami warning for the region. The Hawai'i-based Pacific Tsunami Warning Center, meanwhile, issued a notice that there was no Pacific-wide tsunami. Consequently, emergency agencies issued conflicting reports — some beach areas were evacuated while others were told there was no threat. In addition, some emergency communications equipment was found to be inoperative.

In the end, the tsunami turned out to be too small to cause damage. But confusion surrounding the incident alarmed Hawai'i Civil Defense officials, although they point out that Hawai'i's own warning system is different.

"Part of the problem is that they haven't practiced any of that, and we do," said Jeanne Johnston, earthquake and tsunami program manager for state Civil Defense in Hawai'i.

Hawai'i emergency officials take their tsunami information from just one source: the Pacific Tsunami Warning Center. Communication lines between state and county emergency centers are tested regularly, and personnel train in disaster scenarios frequently, Johnston said.

In terms of providing warnings, Hawai'i is in better shape than it's ever been, largely because of an infusion of cash in response to the Indian Ocean disaster. McCreery's staff is now increasing from eight members to 15, which will permit 24-hour staffing of warning-center offices. And there also is an increase in detection equipment already in place or soon to be installed on land and in the oceans around the Islands, he said.

One of the key pieces of equipment is a buoy attached to a seafloor sensor that detects the strength of a passing tsunami. Before the Indian Ocean tsunami, there were six buoys, known as Deep-ocean Assessment and Reporting of Tsunami or DART buoys. There are now 10 and there will be a total of 32 in two years — covering the ocean floor from all directions that pose threats to Hawai'i.

"They'll be out there to cover all the major seismic zones in the Pacific," McCreery said.

The biggest tsunami response issue in Hawai'i, several emergency officials said, is the readiness of the civilian population.

Kaua'i Civil Defense coordinator Mark Marshall said he is sure the emergency system will be able to inform the population of a pending disaster but is not sure the public will respond appropriately.

Tsunami evacuation maps are in the front of Hawai'i phone books, along with recommendations for contents of emergency kits and other disaster response information. Still, emergency preparedness officials worry that residents may not use information at their fingertips.

Marshall said that in a 2003 Japan tsunami, despite a robust emergency response mechanism and comparatively frequent emergencies, a large proportion of the population failed to evacuate after being warned.

Johnston said, "People are waiting for the government to protect them, but they need to be responsible for their own families."

Reach Jan TenBruggencate at jant@honoluluadvertiser.com.