Anak Krakatau continues to erupt

In the last 24 hours 5 VONA reports about eruptions at Anak Krakatau were published. In the VSI reports the height of the eruption clouds was given as 357 m above the crater. The VAAC Darwin registered volcanic ash at a height of 600 m. The volcanic ash was recorded in the VSI reports. The longest eruption lasted about 5 minutes and produced a seismic signal with a maximum amplitude of 41 mm.

Piton de la Fournaise: 5th Eruption of the year started

The expected eruption at Piton de la Fournaise started at 14.40 (local time). According to first reports, 2 fissures opened relatively far below the volcanic slope at 1400 m altitude. They are located about 1 km north of Piton Tremblet, which formed in 2007 during a large flank eruption. Several lava flows began to flow, at least one of which is still active and already below the Piton Tremblet. The lava flows at the edge of the older lava field from 2007 and set Vegetaion on fire. Fire-fighting planes are used to fight the flames. Eruptions so far below the volcano often have the potential to interrupt the coastal road. The lava could even reach the sea. It is the 5th volcanic eruption on La Réunion this year.

AVO Cleveland YELLOW/ADVISORY – Unrest continues; elevated temperatures and steaming seen in satellite images

Sep 20, 2019 22:29 – Satellite observations during brief periods of clear weather over the last week showed the typical elevated surface temperatures in the summit crater and minor steam emissions. No ash emissions were observed. Seismicity was quiet occasional local earthquakes. There was nothing significant noted in local or regional infrasound data during the week.

Additional episodes of lava effusion and explosions are likely and will occur without advance warning. The most recent explosion of Cleveland occurred on January 9, 2019. These explosions are normally short duration and only …

AVO Semisopochnoi YELLOW/ADVISORY – Unrest continues; satellite data obscured by clouds. Seismicity is low.

Sep 20, 2019 22:29 – Unrest continues at Semisopochnoi volcano with low-level eruptive activity possible. Seismic activity has generally decreased over the past few weeks and AVO lowered the color code/activity level to YELLOW/ADVISORY on Wednesday September 18, 2019. Satellite observations were mostly obscured by clouds over the past week and no activity was observed.

Semisopochnoi is monitored with an on-island seismic network and remotely by satellite and lightning sensors. Furthermore, an infrasound array on Adak Island may detect explosive emissions from Semisopochnoi with a 13 …

AVO Shishaldin ORANGE/WATCH – Low-level eruption continues with tremor and elevated surface temperatures during week

Sep 20, 2019 22:29 – Low-level eruptive activity within the summit crater continues at Shishaldin. Seismicity remained elevated during the past week and was characterized by low-level tremor. Satellite data have shown elevated surface temperatures at the summit crater when views were not obscured by clouds. Conditions at the volcano appear to have changed little over the past several weeks, with slight growth in the scoria cone and lava flows within the summit crater. The low-level lava fountaining and repetitive minor explosive activity within the summit crater observed on August 17, 2019 is …

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)