(1) VOLCANO OBSERVATORY NOTICE FOR AVIATION (VONA)
(2) Issued:(20090501/1631Z)
(3) Volcano:Cleveland (CAVW# 1101-24-)
(4) Current Color Code:UNASSIGNED
(5) Previous Color Code:
(6) Source:Alaska Volcano Observatory
(7) Notice Number:2009/A35
(8) Volcano Location:N 52 deg 49 min W 169 deg 56 min
(9) Area:Aleutians Alaska
(10) Summit Elevation:5676 ft (1730 m)
(11) Volcanic Activity Summary:AVO is lowering the Aviation Color Code and Alert Level at Cleveland volcano to UNASSIGNED. No volcanic activity of significance has been detected at Cleveland since late January 2009. Satellite images have shown no evidence of ash emission or thermal anomalies in the summit area. Because Cleveland is not monitored in real-time with a seismic network, we cannot confidently state that the volcano has returned completely to a background level of quiescence. Therefore, we use the term UNASSIGNED to characterize the state of the volcano and hazards.

Cleveland volcano has been intermittently active for a number of years with pauses of months between minor ash explosions. Additional ash events can occur without warning and, since the volcano is unmonitored in real-time, ash clouds can go undetected for several hours. AVO uses satellite imagery to evaluate the state of activity at Cleveland. Frequent periods of poor weather can prevent clear views of the volcano for weeks at a time.
(12) Volcanic cloud height:Unknown
(13) Other volcanic cloud information:Unknown
(14) Remarks:Cleveland volcano forms the western half of Chuginadak Island, a remote and uninhabited island in the east central Aleutians. It is located about about 75 km (45 mi.) west of the community of Nikolski, and 1500 km (940 mi.) southwest of Anchorage. The volcano's most recent significant eruption began in February, 2001 consisting of 3 explosive events that produced ash clouds as high as 12 km (39,000 ft) above sea level. This eruption also produced a rubbly lava flow and hot avalanche that reached the sea. The most recent minor ash emissions were observed in January 2009.
(15) Contacts:Tom Murray, Scientist-in-Charge, USGS
tlmurray@usgs.gov (907) 786-7497

Steve McNutt, Coordinating Scientist, UAF
steve@giseis.alaska.edu (907) 474-7131
(16) Next Notice:A new VONA will be issued if conditions change significantly or alert levels are modified. While a VONA is in effect, regularly scheduled updates are posted at
http://www.avo.alaska.edu