Explosion at Cleveland volcano, alert level raised to Orange

A small explosion took place at 05:49 UTC at Cleveland volcano, Alaska on May 5, 2018. 

A small ash cloud was produced rising up to 6.7 km (22 000 feet) above sea level, drifting to the southeast.

A few small earthquakes were also recorded at the volcano during the previous several days. 

In response to increased activity, the Alaska Volcano Observatory (AVO) raised the Aviation Color Code to Orange.

Explosions from Cleveland typically produce relatively small volcanic ash clouds that dissipate within hours; however, more significant ash emissions are possible. 

Cleveland volcano is monitored with a limited real-time seismic network, which inhibits 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.

Geological summary

Beautifully symmetrical Mount Cleveland stratovolcano is situated at the western end of the uninhabited, dumbbell-shaped Chuginadak Island. It lies SE across Carlisle Pass strait from Carlisle volcano and NE across Chuginadak Pass strait from Herbert volcano.

Cleveland is joined to the rest of Chuginadak Island by a low isthmus. The 1730-m-high (5 675 feet) Mount Cleveland is the highest of the Islands of the Four Mountains group and is one of the most active of the Aleutian Islands. The native name for Mount Cleveland, Chuginadak, refers to the Aleut goddess of fire, who was thought to reside on the volcano.

Numerous large lava flows descend the steep-sided flanks. It is possible that some 18^th-to-19^th century eruptions attributed to Carlisle should be ascribed to Cleveland (Miller et al., 1998).

In 1944 Cleveland produced the only known fatality from an Aleutian eruption. Recent eruptions have been characterized by short-lived explosive ash emissions, at times accompanied by lava fountaining and lava flows down the flanks. (GVP)

Featured image credit: USGS/AVO