Wednesday, January 11, 2006

Mt. Augustine Awakens

A webcam image from the AVO, showing Mt. Augustine. Bad weather day, as clouds obscure the top of the mountain - not ash. But under the clouds, you can see brown "rivers" coming down the mountain. Those are lahars, mudflows consisting of ash and melted snow.
From the Alaska Volcano Observatory:
Unrest continues at Augustine Volcano and additional eruptive activity could occur at any time.

AVO recorded two discrete explosions at the summit of Augustine Volcano this morning at 4:44 a.m. and 5:13 a.m. (AST) and responded by changing the level of concern color code from ORANGE to RED. Satellite data confirm that an ash cloud was produced and in collaboration with the National Weather Service (NWS), the height of the cloud was estimated at 30,000 feet above sea level. NWS and AVO are tracking the ash plume which has detached from the vent and is presently drifting to the north and east of Augustine. As of about 10:45 a.m. (AST), the ash cloud has moved little since this morning and is about 30 mi (50 km) east and 45 mi (72 km) north of the volcano. An ash-fall advisory was issued by the NWS at 6:44 a.m. (AST) for the west side of Cook Inlet north of Augustine Island and remains in effect until 2:00 p.m. (AST). AVO has received no confirmed reports of ash fall.

Web camera views of the lower flanks of the volcano indicate that small volcanic mudflows (lahars) have formed and extend to about 500 feet above sea level. These flows pose no hazard beyond Augustine Island.

Seismicity has decreased significantly since the explosions, however, it is likely that stronger seismicity and further volcanic activity will resume.

There is no tsunami hazard associated with the current level of activity.

If the volcano follows a pattern similar to the 1976 and 1986 eruptions, we would expect a further intensification of seismic activity prior to similar or larger explosive events. It is also possible that an explosive eruption could occur with little or no warning.

AVO is monitoring the situation closely and will issue further updates as new information and analyses become available.
For more, check the AVO, or the brief piece I did before Christmas here.

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