A major earthquake measuring 7.7 on the Richter scale hit the Aleutian Islands of Alaska yesterday, prompting warnings of tsunamis, or large waves, reaching as far as Hawaii and Japan.
Ten-foot waves were recorded last night in the Hawaiian Islands, 4,000 miles from the quake's epicenter. Smaller waves were noted in Alaska, British Columbia and Washington state -- but the destructive tsunami that had been feared apparently did not materialize.
It was such fears that prompted officials to order the evacuation of thousands of people from low-lying coastal areas in the Pacific Northwest, Hawaii and Alaska. In California, Coast Guard ships were ordered to sea to protect them in the event of a massive wave.
Instead, however, waves of 2 to 3 feet seemed to be the norm. Those were the levels reported at Neah Bay, Wash., and Kalaloch, about 60 miles south. For some, the tsunami watch became a spectator sport: In Prince Rupert, British Columbia, hundreds of people who had been advised to seek higher ground showed up at the waterfront to see what the fuss was about, and in San Francisco, oceanside restaurants were jammed.
The quake, which was preceded by two smaller temblors and followed by several others, was centered about 80 miles east of Adak, part of the Andreanof Islands in the 1,100-mile Aleutian chain, according to the Alaska Tsunami Warning Center.
A naval air station on Adak sustained minor damage from the quake but no one was injured, the Coast Guard reported. Some of the island's 5,000 residents were temporarily evacuated from coastal regions before a 6-foot wave hit.
The Earthquake Information Center in Golden, Colo., said the quake, which struck at 2:47 p.m. (6:47 p.m. EDT), was the largest in the Andreanof Islands in more than 29 years.
In Hawaii, residents of Hilo, the state's second-largest city, were advised to move inland. Hilo is no stranger to tsunamis -- the city has been devastated by the waves twice, most recently in 1960.
Similar evacuation advisories were in effect on Maui, Oahu and other islands.
Warning sirens alerted residents throughout the state to move inland. On Oahu, city buses were dispatched to pick up people with no other means of transportation. The warning was later canceled.
In Tokyo, the government issued a tsunami warning along Japan's Pacific coast, although Japanese meteorologists said they expected that water levels would rise no more than a few inches.
Tsunamis can result from earthquakes or landslides, above or below water. In the open ocean, they move at great speed, slowing as the water gets shallower. When their forward motion is restricted by land, they swell. A small wave such as the one at Adak can become a 100-foot killer moving at 30 mph when it hits shore.
Tsunamis, often inaccurately called tidal waves, are difficult to detect, in part because they go almost unnoticed in open water.
Although initial reports last night were of small waves, persons knowledgeable about tsunamis did not rule out a larger wave still to come.
The most destructive tsunami ever recorded hit Indonesia in 1883 after the eruption of the volcano Krakatoa. More than 37,000 people were killed.