Cleveland Volcano in Alaska Erupting

New Eruption at Alaska’s Cleveland

Cleveland (background) and Carlisle (foreground) volcanoes in Alaska seen from an Alaska Airlines 737 in May 2012. Image by Cyrus Read, courtesy of AVO/USGS.

Last night, I noted on Twitter that the Alaska Volcano Observatory had increased the alert status at Cleveland to Orange (from Yellow) – this came after a report that an explosive eruption had taken place. Thanks to Cleveland’s remote location, confirmation of the eruption is difficult, but pilot observation, shots from the Cleveland webcam and infrasound all suggests that an explosive eruption took place, with the pilot estimating the plume might have been as high as 10.6 km / 35,000 feet. The eruption appears to be fairly ephemeral (a standard behavior for Cleveland), as satellite images taken around the time that the pilot reported the ash plume show only thin ash around the volcano – this isn’t entirely surprising if the explosion was caused by a collapse of the dome at Cleveland’s summit.

This is pretty much all that is going on in the Aleutians right now – Iliamna, another volcano that showed some restlessness earlier this year, has settled in a pattern of low-level (yet above background) seismicity that leaves it at Yellow alert status. However, the Aleutian’s northern Pacific cousins in Kamchatka are definitely keeping busy, especially Shiveluch, where the volcano has been producing frequent ~6-8 km / 20,000- to 26,000-foot plumes.


Alaska Volcano Alert Level Upped

Cleveland Volcano alerts upgraded on renewed activity (again)

Alaska Dispatch | Jan 31, 2012

According to the Alaska Volcano Observatory, the aviation color color code and the alert level of Cleveland Volcano was upgraded on Tuesday to “Orange” and “Watch” to reflect new satellite data indicating increased activity.

The east central Aleutian Chain volcano, which sits 45 miles west of the community of Nikolski, has spent much of the past year teasing that it would erupt, and its status has alternated between “Yellow/Advisory” and the more serious “Orange/Watch” four times since July 2011.

The AVO reports that the lava dome that had developed at Cleveland last year was mostly removed by a brief explosive episode at the end of December. But new satellite images indicate that a fresh lava dome,approximately 130 feet in diameter, has formed in the summit crater.

There have been no explosions or ash emissions detected during the current lava eruption, but the AVO notes that it remains possible for intermittent, sudden explosions of blocks and ash to occur at any time, and ash clouds exceeding 20,000 feet above sea level may develop.

Because Cleveland is not covered by real-time seismic sensors, such explosions and their associated ash clouds may go undetected in satellite imagery for hours.

Read the latest from the AVO’s Cleveland status page, here, and read the bulletin announcing the new status upgrade from the U.S. Geological Survey, here.