| (1) VOLCANO OBSERVATORY NOTICE FOR AVIATION (VONA) | |
| (2) Issued: | (20120905/2014Z) |
| (3) Volcano: | Cleveland (CAVW# 1101-24-) |
| (4) Current Color Code: | YELLOW |
| (5) Previous Color Code: | orange |
| (6) Source: | Alaska Volcano Observatory |
| (7) Notice Number: | 2012/A11 |
| (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: | Satellite views of Cleveland since the last explosion on 20 August show no evidence of further eruptive activity. The last confident satellite detection of fresh lava within the summit crater was in early May. Based on the apparent hiatus in lava effusion and explosions, it is possible that the current episode of eruptive activity has paused. Therefore, AVO is lowering the Aviation Color Code and Alert Level to Yellow/Advisory. Despite this downgrade, sudden explosions of blocks and ash remain possible with little or no warning. Associated ash clouds could exceed 20,000 feet above sea level. If a large ash-producing event occurs, nearby seismic, infrasound, or volcanic lightning networks should alert AVO staff quickly. However, for some events, a delay of several hours is possible. There is no real-time seismic monitoring network on Mount Cleveland and AVO is unable to track activity in real 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 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. |
| (15) Contacts: | John Power, Scientist-in-Charge, USGS jpower@usgs.gov (907) 786-7497 Jeff Freymueller, Coordinating Scientist, UAFGI jeff.freymueller@gi.alaska.edu (907) 978-5458 |
| (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 |
