Mount Augustine showed no signs of quieting today, as new eruptions sent volcanic ash rocketing 47,000 feet into the air and mud avalanching down its flanks to the sea.

The island volcano, quiet for a decade, belched back to life Thursday with more than 10 explosions of steam and ash that dumped on several Kenai Peninsula communities but veered west of Anchorage, Alaska's largest city.

By noon today, U.S. Geological Survey officials here reported that the volcano, located 175 miles to the southwest, had erupted four more times and that a five-mile-wide band of ash was blowing northward, up Cook Inlet, and raining down on the western edge of the Kenai Peninsula.

In the city of Kenai, about 120 miles northeast of the volcano, the ash fell in a fine dust, turning a recent snowfall a sickly gray-brown color and infusing the air with a sulfuric, rotten-egg stench.

"You walk outside and you kind of feel it in your eyes," said Kim Hammock, a secretary at the Kenai Fire Department. "My hair is all gritty and my eyelashes are pretty bad. It doesn't take long to feel grimy."

The ash plumes moved across Kenai like a large storm cloud, blocking the sun and reducing visibility to less than two miles. By early afternoon, nearly a quarter-inch of volcanic dust had fallen on the city. "When people come inside they look like they are covered with white dust," Hammock said.

As winds kicked up the ash, people with respiratory problems were warned to stay inside. Many outdoor workers donned filter masks.

Anchorage's airport was largely shut down by a thin, upper-atmosphere dust cloud stretching from the Brooks Range in the Arctic, 600 miles north of the volcano, almost to the Canadian border.

"This dust can eat away at the insides of airplane engines," said Paul Steucke, a Federal Aviation Administration official here. An official at Anchorage International Airport, which normally handles 300 flights daily, said that 16 airliners made it in or out of the facility today. One of the planes sustained engine damage.

Elsewhere in this city of about 240,000, it was business as usual today, one day after National Weather Service forecasters said that thick, low-level ash plumes could pass over the city.

Fearing the worst, some employers, including government offices, closed shop early. Stores were jammed with people wanting to stock up on groceries and air filters for their cars.

But the city was spared -- if only temporarily -- as just a trace of ash was noted. Late this afternoon, additional dustings were recorded. The weather service predicted earlier that a wind shift late tonight or early Saturday could blow more ash this way, but that seemed less likely early this evening.

The new eruption is the fifth since 1883 for Mount Augustine, discovered in 1778 by Capt. James Cook. At 4,025 feet, it is one of the smaller volcanoes in an arc stretching 1,500 miles across southwestern Alaska and into the Aleutian Islands.

Geophysicists monitoring the mountain's latest belch are concerned that the ongoing mud and ash slides, which have been estimated at speeds ranging from 50 to 100 miles per hour, could trigger a tidal wave that would fan out from the volcano and hit several coastal communities within 30 minutes.

In 1883 a violent eruption did just that. The resulting 30-foot-high tidal wave deluged houses and swamped boats in the Indian community of Port Graham, according to George Carte, a geophysicist at the Alaska Tsunami Warning Center. Thus far, there are no signs of avalanches large enough to create a tidal wave, Carte said.

Geological Survey volcanologist Tom Miller said that danger is fading since such waves normally are created by the violent first pulses of an eruption. Subsequent pulses usually are weaker, he said.

This morning, most of Mount Augustine's slides stopped short of the ocean.