Alaska Volcano Observatory

From Orr and others, 2023: "On August 1, 2019, AVO received a PIREP of steaming at Mount Veniaminof’s intracaldera cone, which coincided with a weak tremor signal. These observations marked a small but distinct departure from the background level of unrest at the volcano, and as a result, AVO raised the Aviation Color Code and Volcano Alert Level to YELLOW and ADVISORY. Weak seismicity and occasional long-period earthquakes continued intermittently throughout most of August, but by the end of the month, the volcano returned to its background activity level. AVO subsequently lowered the Aviation Color Code and Volcano Alert Level to GREEN and NORMAL on August 25, 2019. No additional unrest took place at Mount Veniaminof for the remainder of 2019."