Volcanic eruption in Alsaka triggers highest aviation alert

A volcanic eruption Sunday prompted the temporary increase of the highest aviation alert, the Alaska Volcano Observatory (AVO) said on Sunday.

The event, which occurred on Alaska's Bogoslof Island, forming part of the Aleutian island chain, led to the issuance of the code "red" aviation alert, which was later downgraded to "orange."

According to the observatory, the plume from the eruption reached at least 35,000 feet, and possibly as high as 45,000 feet.

"We actually went to color code red this afternoon because of numerous lightning detections and increased seismic signals," Jeffrey Freymueller of the Geophysical Institute at the University of Alaska, Fairbanks told CNN.

According to the AVO, the eruption lasted for about 50 minutes.

The volcano is located in the path of many flights from Asia to North America and its ash cloud could adversely affect aircraft. "Ash and aircraft do not mix, as volcanic ash is abrasive, melts at jet engine temperatures, and can cause engine failure," according to the United States Geological Survey.

AVO scientists clicked an image 14 minutes after the start of the eruption, from nearby Unalaska Island, which showed a large white-gray mushroom cloud form over the site. According to the AVO, ash fallout was occurring to the west of the site.

Bogoslof is a tiny sliver of an island less than a kilometre across. According to experts the island is the tip of a much larger underwater volcano.

While the volcano had been in an active eruption cycle since December with some 40 volcanic "events" detected, it not possible for scientists to place monitoring equipment directly on the island.

The island is a constantly shifting landscape of black lava, rocky beaches, and vegetation of only grasses, sedge and heath. It is so small and the volcano so active that sensitive instruments used by researchers to monitor volcanic rumblings cannot be placed there, posing unique challenges for researchers trying to track its activity, according to Michelle Coombs, a scientist with the US Geological Survey's Alaska Volcano Observatory in Anchorage. "If we'd had instruments out there, they probably would have been destroyed 40 times over by now," Alaska Dispatch News quoted her as saying.