Alerts raised for Cleveland volcano after detection of small lava flow, Alaska

The Alaska Volcano Observatory has raised the Aviation Color Code for Cleveland volcano from Yellow to Orange on June 26, 2018, after detection of small lava flow inside summit crater. The last detected explosive activity at Cleveland volcano occurred May 5, 2018. ​

Satellite observations of Cleveland volcano on June 25, 2018, indicate the presence of a small circular lava flow, about 80 meters (262 feet) in diameter, covering the floor of the summit crater, the Alaska Volcano Observatory (AVO) reported June 26 at 21:45 UTC.

Geophysical monitoring data from Cleveland Volcano has been unavailable since early afternoon, June 25 and thus it is unknown if the effusion of lava within the crater generated detectable seismicity or infrasound.

However, the presence of a lava flow over the active vent increases the possibility of a vent clearing explosion over the coming days to weeks and thus AVO raised the Aviation Color Code and Volcano Alert Level to ORANGE/WATCH. 

Occasional, short duration explosive activity with minimal to no precursory signals is common at the volcano, the observatory said, adding that explosions may occur without warning.

Explosions at Cleveland typically produce relatively small volcanic ash clouds that dissipate within hours. However, more significant ash emissions may occur as they have in the past.

Cleveland volcano is monitored by only two seismic stations, which restricts AVO's ability to detect precursory unrest that may lead to an explosive eruption. Rapid detection of an ash-producing eruption may be possible using a combination of seismic, infrasound, lightning, and satellite data.

​Featured image: Cleveland volcano on October 26, 2017. Credit: USGS/AVO