HVO Mauna Loa YELLOW/ADVISORY – Mauna Loa is not erupting. Seismicity above background; continued summit inflation.

Sep 19, 2019 20:08 – Activity Summary: Mauna Loa Volcano is not erupting. Rates of deformation and seismicity have not changed significantly in the past week and persist above long-term background levels.

Observations: During the past week, approximately 90 small-magnitude earthquakes (all smaller than M2.5) were detected beneath the upper elevations of Mauna Loa. Most of the earthquakes occurred at shallow to intermediate depths of less than 10 km (~6 miles) below ground level.

Global Positioning System (GPS) and Interferometric Synthetic Aperture Radar (InSAR) measurements show …

Stromboli (Italy) – Report for 28 August-3 September 2019 – NEW

INGV reported that the paroxysmal eruption at Stromboli recorded at 1217 on 28 August produced an ash plume that rose 4 km above the summit. The eruption consisted of three explosions; the first two occurred at the Area C-S (South Central crater area), and the less intense third event occurred at Area N (north crater area) and ejected material onto the Sciara del Fuoco. Material from the collapse of the eruption plume contributed to the generation of a pyroclastic flow that traveled down the Sciara del Fuoco and several hundred meters out to sea. Morphological changes to Area N were evident after the paroxysm. The complex of small scoria cones, which had grown around the vents during the last few weeks, were destroyed. The NW crater rim of Area N had subsided, allowing lava flows to travel down the Sciara del Fuoco. During an overflight on 30 August volcanologists noted that Area N had collapsed and contained three vents generating Strombolian activity, and Area C-S had one large crater exhibiting Strombolian activity.

Strombolian activity resumed after the paroxysm on 28 August; lava flows from Area N reached the coastline by 1945. The next day lava from Area N flowed halfway down the Sciara del Fuoco at 2123 on 29 August and shed material from the front that rolled down to the coast. A new explosive sequence at Area C-S began at 2243 and produced tephra fall in Ginostra (1.5 km from the summit). A low-intensity explosion was recorded at 2329. A lava flow from Area C-S reached the sea during the early part of 30 August. Strombolian activity persisted at moderate levels during 31 August-3 September.

Source: Sezione di Catania – Osservatorio Etneo (INGV)

Asosan (Japan) – Report for 28 August-3 September 2019

JMA and the Tokyo VAAC reported that an eruptive event at Asosan was recorded at 1929 on 29 August; a plume rose 200 m above the crater rim and drifted N. During 30 August-3 September ash plumes rose as high as 250 m and drifted E, NE, N, and NW. The Alert Level remained at 2 (on a scale of 1-5).

Sources: Japan Meteorological Agency (JMA) ,Tokyo Volcanic Ash Advisory Center (VAAC)

Dukono (Indonesia) – Report for 28 August-3 September 2019

Based on satellite and wind model data, and information from PVMBG, the Darwin VAAC reported that during 28 August-3 September ash plumes from Dukono rose to altitudes of 1.8-2.1 km (6,000-7,000 ft) a.s.l. and drifted in multiple directions. The Alert Level remained at 2 (on a scale of 1-4), and the public was warned to remain outside of the 2-km exclusion zone.

Sources: Darwin Volcanic Ash Advisory Centre (VAAC),Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)

Ebeko (Russia) – Report for 28 August-3 September 2019

KVERT reported that a thermal anomaly over Ebeko was identified in satellite images on 23 August.
Volcanologists in Severo-Kurilsk (Paramushir Island), about 7 km E, observed explosions during 27-28 August that sent ash plumes up to 3 km (10,000 ft) a.s.l. and drifted E. The Aviation Color Code remained at Orange (the second highest level on a four-color scale).

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

AVO Cleveland YELLOW/ADVISORY – Unrest continues; satellite observations obscured by clouds.

Sep 10, 2019 20:12 – Satellite images show highly elevated surface temperatures in the summit crater during periods of good weather over the past day. Local seismic data is out but no activity was detected by regional seismic data or infrasound arrays during the last 24 hours.

Episodes of lava effusion and explosions can occur without advance warning. Explosions from Cleveland are normally short duration and only present a hazard to aviation in the immediate vicinity of the volcano. Larger explosions that present a more widespread hazard to aviation are possible, but are less likely and …

AVO Semisopochnoi ORANGE/WATCH – Seismicity remains elevated.

Sep 10, 2019 20:12 – Low-level eruptive activity may be continuing at Semisopochnoi. Seismic activity over the past day remains elevated with low-frequency earthquakes but there were no explosions detected in regional infrasound data. Satellite observations were mostly obscured by clouds over the past day.

Semisopochnoi is monitored with an on-island seismic network and remotely by satellite and lightning sensors. An infrasound array on Adak Island may detect explosive emissions from Semisopochnoi with a slight delay (approximately 13 minutes) if atmospheric conditions permit.

AVO Shishaldin ORANGE/WATCH – Low-level eruption continues; elevated surface temperatures observed in satellite

Sep 10, 2019 20:12 – Low-level eruptive activity continues at Shishaldin volcano. Seismicity remains elevated with steady tremor detected over the past day. Satellite images show highly elevated surface temperatures in the summit crater, Clear web camera images from this morning show no evidence of hot deposits on the upper flank as suggested by satellite data from yesterday.

Shishaldin is monitored by local seismic and infrasound sensors, satellite data, a web camera, a telemetered geodetic network, and distant infrasound and lightning networks.