Steve Quayle News Alerts

August 11, 2003
By DOUG O'HARRA
Anchorage Daily News

Scientists surveying deep coral habitat in the Aleutian Chain have discovered and mapped the region's first confirmed undersea volcano.

Its "beautiful conical shape" rises more than 1,900 feet from the floor of Amchitka Pass where strong currents flush between the Pacific Ocean and the Bering Sea.

The black lava rock on what may become the next Aleutian island reaches within 380 feet of the surface and supports a profusion of coral, invertebrates, fish and other sea life, say the biologists and geologists working on the project.

"There's no crater in the summit that we can see, but it's just this perfect volcano shape," said Jennifer Reynolds, a marine geologist at the Global Undersea Research Unit of the University of Alaska Fairbanks and the science director of the West Coast and Polar Regions Undersea Research Center. "I can see lava flows going off it downslope to the sea floor, and they're going off the map" for 8.7 miles.

"It's pretty spectacular," added biologist Bob Stone, a National Marine Fisheries Service scientist who first dived on the summit last summer in a two-person submarine and returned again this year. "It's covered with coral like I've seen in no other place. It certainly looks to me like a tropicallike landscape."

Detailed mapping conducted this June by Reynolds and a team aboard the research vessel Davidson with multibeam sonar revealed the volcano to be a medium-sized cone, four miles across at the base. It lies about 12 miles southeast of Semisopochnoi Island, just across the 180-degree meridian in the Eastern Hemisphere. It's about one-third to one-half the height of its sister volcanoes above the surface on nearby Gareloi, Tanaga and Little Sitkin islands, Reynolds said in a written statement.

A strong eruption with lots of lava could conceivably surge above the waves and create a new island, though no one knows yet how often the volcano erupts or when it might blow again, Reynolds said.

"Undersea volcanoes tend to go back and forth and then get eroded," she said. "It's very difficult for them to get built up permanently above sea level."

Aleut oral stories describe the emergence of Kasatochi Island west of Atka, Reynolds said. Tiny Bogoslof Island west of Dutch Harbor was created largely by eruptions during the 18th and 19th centuries. But sorting out this volcano's potential to build new land will require further scientific studies of its rocks, sea life and sediments.

"There is quite a bit of coral on this feature," Reynolds said. "Which means that it didn't erupt 10 years ago, at least on the side that they dove on."

Volcanologists say the new cone could tell more about the workings of the Aleutian volcanoes, created by immense geologic forces as the Pacific tectonic plate gets squashed deeper into Earth's crust beneath the North American plate.

"I would love to take a look at this thing and see what it's doing," said Jackie Caplan-Auerbach, a researcher with the Alaska Volcano Observatory who wrote her dissertation on the undersea volcano building from the sea floor east of Hawaii.

The observatory monitors 24 volcanoes in Alaska and other volcanoes in the Russian Far East with seismic networks and satellite coverage, then issues warnings and information about eruptions. Those closely watched volcanoes include snowy Mount Spurr, visible 80 miles west of Anchorage, whose summer 1992 eruption coated the region in ash and disrupted air traffic.

The new cone won't pose the same hazard as active terrestrial volcanoes because it probably can't drive enough ash into the atmosphere to endanger aircraft, said Tom Murray, the observatory's scientist in charge.

Still, you wouldn't want to sail right over the new volcano during an eruption, said Reynolds and Caplan-Auerbach. Even if debris doesn't blast from the sea, the force and heat generated could change the density and buoyancy of the ocean enough to sink a vessel. Historical records suggest that's happened at least once, said Caplan-Auerbach.

"To my mind, the best thing to do would be to have some sort of monitoring system out there, and if it shows signs of coming to life, then you don't send ships over it," Reynolds said.

The observatory hopes to install seismic networks on Semisopochnoi and other nearby islands in the next few years. Those networks will almost certainly register tremors if the undersea cone stirs to life, Caplan-Auerbach said.

The volcano was mapped as part of an ongoing study of coral and its habitat by UAF scientists in collaboration with the National Marine Fisheries Service at Auke Bay Lab in Juneau and the Alaska Department of Fish and Game, with funding from the North Pacific Research Board and the National Oceanic and Atmospheric Administration.

The cone first came to light last summer after Stone and other biologists noticed the black, lavalike rock underlying coral on a feature they originally thought was just a big undersea pinnacle.

When they planned this summer's work, Reynolds made sure one of the tracks traversed the feature, which she suspected was actually a volcano. Her geology team spent 30 days mapping 17 strips of sea floor in the Aleutians. A biological team led by Stone followed in another vessel, diving up to 1,250 feet deep in the Delta submersible. They made 24 dives at 10 sites, collecting samples and taking video.

"The Aleutian Islands have more of these corals than any other cold place in the world," Stone said. "It's got scientists from around the world pretty excited about it."

As the lead geologist, Reynolds could take the liberty to name the new volcano. But she contacted an Aleut language expert in Unalaska who promised to consult with Native elders across the region for an appropriate name.

Reynolds said her only condition was that it be pronounceable in English.

"I really think features like this should have local names," she said. "If it were out in the middle of the Pacific and there was nobody for 1,000 miles, then, sure, I would pick a name. But this one is in the middle of the Aleutian Chain. It's not that far from Atka village and Adak. People go out there."

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