Amidst reports of an intense eruption of the Alaska volcano Bogoslof at 1:20 p.m. Wednesday and fanned out ash clouds to a height of 31,000 feet threatening aviation traffic, the MODIS instrument (Moderate Resolution Imaging Spectroradiometer) aboard NASA's Terra satellite has captured vivid images of the volcano's ash plumes engulfed by white clouds.
The satellite passed above the volcano after the eruption.
The real-time images taken on Jan. 18 showed volcanic ash plume as dark brown. The plumes stood out as they were huddled in the middle of white clouds associated with a low-pressure system being formed north of the area.
Bogoslof Island is at the peak of a large submarine stratovolcano lying at a height of 6,000 ft above the Bering Sea floor. At the highest point, the volcano is barely 300 feet above sea level where frequent eruptions and erosions are common.
Eruption Updates From AVO
The Alaska Volcano Observatory (AVO) has been providing timely updates on eruption levels. In the latest update, AVO also confirmed the passage of Terra satellite overhead when dark ash clouds were spilling out northeast of Bogoslof. According to latest reports, the ash cloud emissions have now settled down.
The Unalaska police updated that there had been no reports of ash fall overnight Wednesday. The observatory and National Weather Service also had no reports of ash falling on land until Thursday afternoon.
"This cloud was darker in color, and presumably more ash-rich, than others we have seen in the eruptive sequence, which began in mid-December 2016. This image also suggests the presence of very hot material (lava) at the surface immediately surrounding the vent - the first such observation during this eruption sequence," AVO announced.
High Alert For Aviation
The AVO had raised the highest threat code for aviation — Red, which is the top indicator. When volcanic ash clouds zoom above 20,000 feet, there is a threat to jet aircraft with possible damage to the engines.
"Pilots reported the cloud reached a height greater than 31,000 ft (above sea level), and prevailing winds carried it northeast over the Bering Sea," an AVO official said.
Meanwhile, Robert Easton, an aviation forecaster with the National Weather Service's said an advisory has been issued to aviators tracking the cloud's location. But that was withdrawn Thursday morning as ash was not visible on radar.
Satellite photos indicated that the cloud was moving to the northeast along the Bering Sea. The volcano has already erupted multiple times since the big eruption on Dec. 16.
According to sources, satellite image showed that some ash cloud northeast of Bogoslof that was "darker in color, and presumably more ash-rich, than others we have seen in the eruptive sequence" since mid-December.
