(1) VOLCANO OBSERVATORY NOTICE FOR AVIATION (VONA)
(2) Issued:	(20170203/2305Z)
(3) Volcano:	Cleveland (VNUM #311240)
(4) Current Color Code:	ORANGE
(5) Previous Color Code:	YELLOW
(6) Source:	Alaska Volcano Observatory
(7) Notice Number:	2017/A87
(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 satellite observations indicate that a new lava dome has been extruded and is partially filling the summit crater at Cleveland volcano. The new dome is about 70 m (230 feet) in diameter and is similar in size to previous lava domes that have developed on the floor of the crater. When lava domes have developed within the summit crater, explosive activity has sometimes followed. The extrusion of the lava dome and the increased potential for explosive activity prompts AVO to change the Aviation Color Code to ORANGE and the Volcano Alert Level to WATCH. Cleveland volcano is not monitored with a real-time seismic network and this inhibits AVO's ability to detect unrest that may lead to an explosive eruption. Rapid detection of an ash-producing eruption may be possible using a combination of satellite, infrasound, lightning data and local observations. AVO is monitoring the unrest at Cleveland volcano as closely as possible and will release additional information if or when it becomes available.
(12) Volcanic cloud height:	No volcanic clouds observed.
(13) Other volcanic cloud information:	No cloud observed.
(14) Remarks:	Cleveland volcano forms the western portion of Chuginadak Island, a remote and uninhabited island in the east central Aleutians. The volcano is located about 75 km (45 mi) west of the community of Nikolski, and 1500 km (940 mi) southwest of Anchorage. The most recent significant period of eruption began in February, 2001 and produced 3 explosive events that generated ash clouds as high as 39,000 ft above sea level. The 2001 eruption also produced a lava flow and hot avalanche that reached the sea. Since then, Cleveland has been intermittently active producing small lava flows, often followed by explosions that generate small ash clouds generally below 20,000 ft above sea level. These explosions also launch debris onto the slopes of the cone producing hot pyroclastic avalanches and lahars that sometimes reach the coastline.
(15) Contacts:	Michelle Coombs, Scientist-in-Charge, USGS mcoombs@usgs.gov (907) 786-7497 Jeff Freymueller, Coordinating Scientist, UAFGI jfreymueller@alaska.edu (907) 322-4085
(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: WATCH
Previous Volcano Alert Level: ADVISORY

Current Aviation Color Code: ORANGE
Previous Aviation Color Code: YELLOW

Issued: Friday, February 3, 2017, 2:05 PM AKST
Source: Alaska Volcano Observatory
Notice Number: 2017/A87
Location: N 52 deg 49 min W 169 deg 56 min
Elevation: 5676 ft (1730 m)
Area: Aleutians

Volcanic Activity Summary: Recent satellite observations indicate that a new lava dome has been extruded and is partially filling the summit crater at Cleveland volcano. The new dome is about 70 m (230 feet) in diameter and is similar in size to previous lava domes that have developed on the floor of the crater. When lava domes have developed within the summit crater, explosive activity has sometimes followed. The extrusion of the lava dome and the increased potential for explosive activity prompts AVO to change the Aviation Color Code to ORANGE and the Volcano Alert Level to WATCH.

Cleveland volcano is not monitored with a real-time seismic network and this inhibits AVO's ability to detect unrest that may lead to an explosive eruption. Rapid detection of an ash-producing eruption may be possible using a combination of satellite, infrasound, lightning data and local observations. AVO is monitoring the unrest at Cleveland volcano as closely as possible and will release additional information if or when it becomes available.


Recent Observations:
[Volcanic cloud height] No volcanic clouds observed.
[Other volcanic cloud information] No cloud observed.

Remarks: Cleveland volcano forms the western portion of Chuginadak Island, a remote and uninhabited island in the east central Aleutians. The volcano is located about 75 km (45 mi) west of the community of Nikolski, and 1500 km (940 mi) southwest of Anchorage. The most recent significant period of eruption began in February, 2001 and produced 3 explosive events that generated ash clouds as high as 39,000 ft above sea level. The 2001 eruption also produced a lava flow and hot avalanche that reached the sea. Since then, Cleveland has been intermittently active producing small lava flows, often followed by explosions that generate small ash clouds generally below 20,000 ft above sea level. These explosions also launch debris onto the slopes of the cone producing hot pyroclastic avalanches and lahars that sometimes reach the coastline.

Contacts: Michelle Coombs, Scientist-in-Charge, USGS
mcoombs@usgs.gov (907) 786-7497

Jeff Freymueller, Coordinating Scientist, UAFGI
jfreymueller@alaska.edu (907) 322-4085

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

The Alaska Volcano Observatory is a cooperative program of the U.S. Geological Survey, the University of Alaska Fairbanks Geophysical Institute, and the Alaska Division of Geological and Geophysical Surveys.

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