Pavlof 2019
Start: October 19, 2019 [1]
Stop: October 19, 2019 [1]
Event Type: Not an eruption
- Minor explosive eruption [2]
Description: On October 19, AVO raised the Aviation Color Code and Volcanic Alert Level at Pavlof to YELLOW/ADVISORY. From the Volcano Observatory Notice for Aviation: "Small explosion signals from Pavlof have been detected on the infrasound network located at Sand Point and on the local seismic network today. The volcano is currently obscured by clouds in satellite images. It is unknown if the explosions produced any volcanic ash, but their small size suggests any hazard is currently confined to the area around the volcano's summit. Because these signals are above normal background for Pavlof, the Alaska Volcano Observatory is raising the Aviation Color Code to YELLOW and the Alert Level to ADVISORY." On November 6, 2019, AVO lowered the Aviation Color Code and Volcano Alert Level to GREEN/NORMAL, citing no additional signs of unrest after the explosion signals on October 19.
From Orr and others, 2023: "In 2019, Pavlof Volcano showed signs of weak activity that caused AVO to raise the Aviation Color Code and Volcano Alert Level to YELLOW and ADVISORY three times...They were raised...to YELLOW and ADVISORY on October 19 when small explosion signals were detected by the infrasound array in Sand Point and on the local seismic network, then were lowered back to GREEN and NORMAL on November 6...
"A total of 90 earthquakes were located within 20 km of Pavlof Volcano during 2019. Of these events, 44 were classified as volcano-tectonic (VT) earthquakes, with a collective depth range of −2.85 to 31.5 km and a local magnitude (ML) range of −0.41 to 1.65. The other 46 were classified as LP earthquakes, with a depth range of 8 to 34 km and a ML range of −0.36 to 1.65. Of the 46 LP events, 21 were located ~5 km northeast of Pavlof Volcano beneath Pavlof Sister, a pattern also seen in the seismicity of previous years (Power and others, 2004b). AVO recorded several tremor episodes at Pavlof Volcano in 2019. There is no obvious temporal relationship between the tremor and the earthquake activity...The activity of 2019 ended with additional tremor pulses that took place on October 18 and December 14.
"The annual number of earthquakes located at Pavlof Volcano increased between 2017 and 2019. This trend is probably influenced by improvements made to Pavlof Volcano’s seismic network in the summer of 2017, but the fact that AVO located significantly fewer events in 2019 than 2018 suggests a change in activity level unrelated to the network improvements."
From Orr and others, 2023: "In 2019, Pavlof Volcano showed signs of weak activity that caused AVO to raise the Aviation Color Code and Volcano Alert Level to YELLOW and ADVISORY three times...They were raised...to YELLOW and ADVISORY on October 19 when small explosion signals were detected by the infrasound array in Sand Point and on the local seismic network, then were lowered back to GREEN and NORMAL on November 6...
"A total of 90 earthquakes were located within 20 km of Pavlof Volcano during 2019. Of these events, 44 were classified as volcano-tectonic (VT) earthquakes, with a collective depth range of −2.85 to 31.5 km and a local magnitude (ML) range of −0.41 to 1.65. The other 46 were classified as LP earthquakes, with a depth range of 8 to 34 km and a ML range of −0.36 to 1.65. Of the 46 LP events, 21 were located ~5 km northeast of Pavlof Volcano beneath Pavlof Sister, a pattern also seen in the seismicity of previous years (Power and others, 2004b). AVO recorded several tremor episodes at Pavlof Volcano in 2019. There is no obvious temporal relationship between the tremor and the earthquake activity...The activity of 2019 ended with additional tremor pulses that took place on October 18 and December 14.
"The annual number of earthquakes located at Pavlof Volcano increased between 2017 and 2019. This trend is probably influenced by improvements made to Pavlof Volcano’s seismic network in the summer of 2017, but the fact that AVO located significantly fewer events in 2019 than 2018 suggests a change in activity level unrelated to the network improvements."
References Cited
[1] Alaska Volcano Observatory website, 2005
Alaska Volcano Observatory, 2005-, Alaska Volcano Observatory website: http://www.avo.alaska.edu.[2] 2019 Volcanic activity in Alaska—Summary of events and response of the Alaska Volcano Observatory, 2023
Orr, T.R., Cameron, C.E., Dietterich, H.R., Dixon, J.P., Enders, M.L., Grapenthin, R., Iezzi, A.M., Loewen, M.W., Power, J.A., Searcy, C., Tepp, G., Toney, L., Waythomas, C.F., and Wech, A.G., 2023, 2019 Volcanic activity in Alaska - Summary of events and response of the Alaska Volcano Observatory: U.S. Geological Survey Scientific Investigations Report 2023-5039, 64 p., https://doi.org/10.3133/sir20235039.
Complete Eruption References
2019 Volcanic activity in Alaska—Summary of events and response of the Alaska Volcano Observatory, 2023
Orr, T.R., Cameron, C.E., Dietterich, H.R., Dixon, J.P., Enders, M.L., Grapenthin, R., Iezzi, A.M., Loewen, M.W., Power, J.A., Searcy, C., Tepp, G., Toney, L., Waythomas, C.F., and Wech, A.G., 2023, 2019 Volcanic activity in Alaska - Summary of events and response of the Alaska Volcano Observatory: U.S. Geological Survey Scientific Investigations Report 2023-5039, 64 p., https://doi.org/10.3133/sir20235039.

Automatic identification and quantification of volcanic hotspots in Alaska using HotLINK: the hotspot learning and identification network, 2024
Saunders-Schultz, P., Lopez, T., Dietterich, H., and Girona, T., 2024, Automatic identification and quantification of volcanic hotspots in Alaska using HotLINK - the hotspot learning and identification network: Frontiers in Earth Science v. 12, 1345104. https://doi.org/10.3389/feart.2024.1345104
