(1) VOLCANO OBSERVATORY NOTICE FOR AVIATION (VONA)
(2) Issued:	(20100826/2352Z)
(3) Volcano:	Cleveland (VNUM #311240)
(4) Current Color Code:	YELLOW
(5) Previous Color Code:	UNASSIGNED
(6) Source:	Alaska Volcano Observatory
(7) Notice Number:	2010/A6
(8) Volcano Location:	N 52 deg 49 min W 169 deg 56 min
(9) Area:	Aleutians
(10) Summit Elevation:	5676 ft (1730 m)
(11) Volcanic Activity Summary:	Recent clear-weather satellite views of Cleveland volcano detect a persistent thermal anomaly at the summit of Cleveland. The presence such an anomaly increases the probability of an ash emission from Cleveland. AVO is therefore moving the volcano alert level/aviation color code from UNASSIGNED to Advisory/Yellow. AVO continues to monitor the volcano using satellite imagery. Without a real-time seismic network at Cleveland, AVO is unable to track local earthquake activity related to volcanic unrest. Low-level ash emissions at Cleveland occur frequently and do not necessarily mean a larger eruption is imminent. Short-lived explosions with ash clouds or plumes that could exceed 20,000 ft above sea level can occur without warning and may go undetected on satellite imagery.
(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 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 and it produced 3 explosive events that produced ash clouds as high as 12 km (39,000 ft) above sea level. The 2001 eruption also produced a rubbly lava flow and hot avalanche that reached the sea. The most recent minor ash emissions were observed in January and June 2009.
(15) Contacts:	Chris Waythomas, Acting Scientist-in-Charge, USGS chris@usgs.gov (907) 786-7497 Steve McNutt, Coordinating Scientist, UAF steve@giseis.alaska.edu (907) 474-7131
(16) Next Notice:	A new VAN will be issued if conditions change significantly or alert levels are modified. While a VAN is in effect, regularly scheduled updates are posted at http://www.avo.alaska.edu

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AVO/USGS Volcanic Activity Notice

Volcano: Cleveland (VNUM #311240)

Current Volcano Alert Level: ADVISORY
Previous Volcano Alert Level: UNASSIGNED

Current Aviation Color Code: YELLOW
Previous Aviation Color Code: UNASSIGNED

Issued: Thursday, August 26, 2010, 3:52 PM AKDT
Source: Alaska Volcano Observatory
Notice Number: 2010/A6
Location: N 52 deg 49 min W 169 deg 56 min
Elevation: 5676 ft (1730 m)
Area: Aleutians

Volcanic Activity Summary: Recent clear-weather satellite views of Cleveland volcano detect a persistent thermal anomaly at the summit of Cleveland. The presence such an anomaly increases the probability of an ash emission from Cleveland. AVO is therefore moving the volcano alert level/aviation color code from UNASSIGNED to Advisory/Yellow. AVO continues to monitor the volcano using satellite imagery.

Without a real-time seismic network at Cleveland, AVO is unable to track local earthquake activity related to volcanic unrest. Low-level ash emissions at Cleveland occur frequently and do not necessarily mean a larger eruption is imminent. Short-lived explosions with ash clouds or plumes that could exceed 20,000 ft above sea level can occur without warning and may go undetected on satellite imagery.


Recent Observations:
[Volcanic cloud height] Unknown
[Other volcanic cloud information] Unknown

Remarks: Cleveland volcano forms the western half of Chuginadak Island, a remote and uninhabited island in the east central Aleutians. It is located 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 and it produced 3 explosive events that produced ash clouds as high as 12 km (39,000 ft) above sea level. The 2001 eruption also produced a rubbly lava flow and hot avalanche that reached the sea. The most recent minor ash emissions were observed in January and June 2009.

Contacts: Chris Waythomas, Acting Scientist-in-Charge, USGS
chris@usgs.gov (907) 786-7497

Steve McNutt, Coordinating Scientist, UAF
steve@giseis.alaska.edu (907) 474-7131

Next Notice: A new VAN will be issued if conditions change significantly or alert levels are modified. While a VAN is in effect, regularly scheduled updates are posted at
http://www.avo.alaska.edu

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