Asamayama (Japan)

A new eruption, or volcanic unrest was detected by the volcanologists an published by the GVP. The details are summarized in the following message:

On 25 June JMA raised the Alert Level for Asamayama to 2 (on a scale of 1-5) noting that inflation on the W flank had been recorded since 20 June. The number of shallow (just below the summit, or 1-2 km a.s.l.) volcanic earthquakes had also increased; two volcanic tremors were detected on 20 June. Emissions form the summit crater had not changed and continued to be white in color and rise no more than 200 m above the crater rim.

Source: Japan Meteorological Agency (JMA)

Makushin (United States)

A new eruption, or volcanic unrest was detected by the volcanologists an published by the GVP. The details are summarized in the following message:

AVO reported continuing numerous smaller earthquakes in an area about 10 km E of the Makushin?s summit at a depth of about 8 km during 24-30 June; the frequency and magnitude had been declining since 15 June but the rate became variable on 24 June. No surficial activity was visible in satellite or webcam images; only typical minor steaming from summit crater lake. Earthquakes with a M 3 and M 3.8 were recorded at 1653 and 1802 on 28 June, with the larger event strongly felt in Unalaska (14 km E). The Aviation Color Code and Volcano Alert Level remained at Yellow and Advisory, respectively.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

Turrialba (Costa Rica)

A new eruption, or volcanic unrest was detected by the volcanologists an published by the GVP. The details are summarized in the following message:

OVSICORI-UNA reported that occasional small ash emissions rose no higher than 100 m above the active crater at Turrialba each day during 23-29 June; no emissions were recorded on 27 June. A series of ash emissions were recorded at 1348, 1739, and 2303 on 28 June and at 0107, 0232, 0306, 0412, and 0818 on 28 June. At least two of those events (0107 and 0412) were accompanied by ballistics that were ejected onto the N wall of the active crater.

Source: Observatorio Vulcanologico y Sismologico de Costa Rica-Universidad Nacional (OVSICORI-UNA)

Aira (Japan)

A new eruption, or volcanic unrest was detected by the volcanologists an published by the GVP. The details are summarized in the following message:

JMA reported that during 22-26 June two eruptive events at Minamidake Crater (at Aira Caldera?s Sakurajima volcano) produced plumes that rose as high as 1,300 m above the crater rim. An explosion at 1807 on 28 June ejected material 1,000-1,300 m away from the crater and produced a plume that rose 600 m above the crater rim. The Alert Level remained at 3 (on a 5-level scale).

Source: Japan Meteorological Agency (JMA)

Dukono (Indonesia)

A new eruption, or volcanic unrest was detected by the volcanologists an published by the GVP. The details are summarized in the following message:

Based on satellite and wind model data, and information from PVMBG the Darwin VAAC reported that during 24 and 26-30 June ash plumes from Dukono rose to 2.1 km (7,000 ft) a.s.l. and drifted NW and W. 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)

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)