Asamayama (Japan) – Report for 14 August-20 August 2019

JMA reported that, after a small phreatic eruption occurred at Asamayama on 7 August, both seismic activity and sulfur dioxide emissions temporarily increased and then decreased later that day. During 8-19 August white plumes generally rose 400 m above the crater rim; occasionally they rose as high as 800 m. Sulfur dioxide emissions were 70-300 tons per day. On 19 August the Alert Level was lowered to 2 (on a scale of 1-5).

Source: Japan Meteorological Agency (JMA)

Semisopochnoi (United States) – Report for 14 August-20 August 2019 – NEW

AVO reported that during 14-17 August seismicity at Semisopochnoi remained elevated and was characterized by periods of continuous tremor and discrete low-frequency earthquakes; seismic data became unavailable starting sometime on 17 August. Cloudy weather often prevented satellite views of the volcano, however some recent clear views indicated that the N cone crater had a smooth featureless area, indicating water or tephra at an elevation several meters below the previous floor. The Volcano Alert Level remained at Watch and the Aviation Color Code remained at Orange.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

Shishaldin (United States) – Report for 14 August-20 August 2019 – NEW

AVO reported that during 14-20 August continuous, low-level tremor at Shishaldin was recorded by the seismic network and elevated surface temperatures were visible in infrared satellite images. The spatter cone in the crater had grown and partially filled the summit crater. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

Tangkubanparahu (Indonesia) – Report for 14 August-20 August 2019 – NEW

PVMBG reported that during 12-18 August phreatic events at Tangkubanparahu’s Ratu Crater continued to produce sometimes dense gray-to-white plumes that rose as high as 200 m above the vent, and dense black ash plumes that rose as high as 100 m. The emissions were accompanied by roaring. Ashfall was localized around Ratu Crater. The seismic network recorded continuous tremor. The Alert Level remained at 2 (on a scale of 1-4), and the public was warned to stay 1.5 km away from the active crater.

Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)

Ubinas (Peru) – Report for 14 August-20 August 2019 – NEW

IGP reported that during 13-19 August blue-colored gas plumes from Ubinas rose to heights of less than 1.5 km above the base of the crater. Seven thermal anomalies were recorded by the MIROVA system. The number of seismic events was 1,716 (all under M 2.4), a decrease in the total number recorded during the previous week. The Alert Level remained at Orange (the second highest level on a four-color scale) and the public were warned to stay outside of a 15-km radius.

Source: Instituto Geofísico del Perú (IGP)