(1) VOLCANO OBSERVATORY NOTICE FOR AVIATION (VONA) | |
(2) Issued: | (20191017/1906Z) |
(3) Volcano: | Shishaldin (VNUM #311360) |
(4) Current Color Code: | ORANGE |
(5) Previous Color Code: | YELLOW |
(6) Source: | Alaska Volcano Observatory |
(7) Notice Number: | |
(8) Volcano Location: | N 54 deg 45 min W 163 deg 58 min |
(9) Area: | Aleutians |
(10) Summit Elevation: | 9373 ft (2857 m) |
(11) Volcanic Activity Summary: | Observations from today show that a new lava effusion event began at Shishaldin on 13 October. Elevated surface temperatures have been observed at the summit of Shishaldin and low-level seismicity continues on the local network indicating that eruptive activity is likely continuing. The eruption is confined to the summit area and no ash clouds have been observed. The Alaska Volcano Observatory is raising the Aviation Color Code for Shishaldin Volcano to ORANGE and the Alert Level to WATCH. Shishaldin is monitored by local seismic and infrasound sensors, satellite data, a web camera, a telemetered geodetic network, and distant infrasound and lightning networks. |
(12) Volcanic cloud height: | None |
(13) Other volcanic cloud information: | N/A |
(14) Remarks: | Shishaldin volcano, located near the center of Unimak Island in the eastern Aleutian Islands, is a spectacular symmetric cone with a base diameter of approximately 16 km (10 mi). A 200-m-wide (660 ft) funnel-shaped summit crater typically emits a steam plume and occasional small amounts of ash. Shishaldin is one of the most active volcanoes in the Aleutian volcanic arc, with at least 54 episodes of unrest including over 24 confirmed eruptions since 1775. Most eruptions are relatively small, although the April-May 1999 event generated an ash column that reached 45,000 ft above sea level. |
(15) Contacts: | Michelle Coombs, Scientist-in-Charge, USGS mcoombs@usgs.gov (907) 786-7497 Taryn Lopez, Acting Coordinating Scientist, UAFGI tmlopez@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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