(1) VOLCANO OBSERVATORY NOTICE FOR AVIATION (VONA)
(2) Issued:	(20170419/2023Z)
(3) Volcano:	Bogoslof (VNUM #311300)
(4) Current Color Code:	YELLOW
(5) Previous Color Code:	ORANGE
(6) Source:	Alaska Volcano Observatory
(7) Notice Number:
(8) Volcano Location:	N 53 deg 55 min W 168 deg 2 min
(9) Area:	Aleutians
(10) Summit Elevation:	492 ft (150 m)
(11) Volcanic Activity Summary:	No new volcanic activity has been observed at Bogoslof Volcano in satellite, seismic or infrasound data since a short-lived increase in seismicity on April 15. The last major explosive event occurred on March 8, 2017, and occasional high-spatial resolution satellite images show no significant surficial changes due to eruptive activity since that time. Based on the absence of detected activity over the past several days, AVO is lowering the Aviation Color Code to YELLOW and the Volcano Alert Level to ADVISORY. Bogolsof is not monitored by a real-time seismic network and this inhibits AVO's ability to detect unrest that may lead to an explosive eruption. Rapid detection, and possible forecasting, of an ash-producing eruption may be possible using a combination of data from seismic and infrasound networks on neighboring islands and satellite and lightning detection data.
(12) Volcanic cloud height:	N/A
(13) Other volcanic cloud information:	N/A
(14) Remarks:	Given the lack of a local monitoring network and the unpredictability of the volcano, activity at Bogoslof could ramp up again at any time. Thus a Temporary Flight Restriction (TFR) remains in effect over the volcano for the time being. Please see http://tfr.faa.gov/tfr2/list.html for the status of the TFR.
(15) Contacts:	Michelle Coombs, Scientist-in-Charge, USGS mcoombs@usgs.gov (907) 786-7497 Jessica Larsen, Acting Coordinating Scientist, UAF jflarsen@alaska.edu (907) 322-4085
(16) Next Notice:

---

AVO/USGS Volcanic Activity Notice

Volcano: Bogoslof (VNUM #311300)

Current Volcano Alert Level: ADVISORY
Previous Volcano Alert Level: WATCH

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

Issued: Wednesday, April 19, 2017, 12:23 PM AKDT
Source: Alaska Volcano Observatory
Notice Number:
Location: N 53 deg 55 min W 168 deg 2 min
Elevation: 492 ft (150 m)
Area: Aleutians

Volcanic Activity Summary: No new volcanic activity has been observed at Bogoslof Volcano in satellite, seismic or infrasound data since a short-lived increase in seismicity on April 15. The last major explosive event occurred on March 8, 2017, and occasional high-spatial resolution satellite images show no significant surficial changes due to eruptive activity since that time. Based on the absence of detected activity over the past several days, AVO is lowering the Aviation Color Code to YELLOW and the Volcano Alert Level to ADVISORY. Bogolsof is not monitored by a real-time seismic network and this inhibits AVO's ability to detect unrest that may lead to an explosive eruption. Rapid detection, and possible forecasting, of an ash-producing eruption may be possible using a combination of data from seismic and infrasound networks on neighboring islands and satellite and lightning detection data.

Recent Observations:
[Volcanic cloud height] N/A
[Other volcanic cloud information] N/A
[Lava flow/dome] N/A
[Lava flow] N/A

Remarks: Given the lack of a local monitoring network and the unpredictability of the volcano, activity at Bogoslof could ramp up again at any time. Thus a Temporary Flight Restriction (TFR) remains in effect over the volcano for the time being. Please see http://tfr.faa.gov/tfr2/list.html for the status of the TFR.

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

Jessica Larsen, Acting Coordinating Scientist, UAF
jflarsen@alaska.edu (907) 322-4085

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.

---