The Semeru volcano on Java generated a major pyroclastic flow. It covered a distance of 4500 m. Volcanic ash rose to an altitude of 5500 m above normal zero. MAGMA volcanologists recorded a seismic signal that lasted 4287 seconds. The amplitude was 22 mm.
Marc Szeglat
Merapi: Descent of a pyroclastic flow
In the early morning hours today, a pyroclastic flow descended from Merapi on Java (Indonesia). It flowed through Kali Krasak and covered a sliding distance of about 1500 meters. Volcanic ash rose about 500 m high and drifted in an easterly direction. The seismograms registered a signal with a maximum amplitude of 60 mm and 150 seconds duration. Yesterday, seismicity picked up again somewhat and 200 shocks were detected. Among them were some hybrid and volcanotectonic earthquakes. There could be 2 reasons for the general downward trend in seismicity: either less magma is rising, or the ascent paths are clear. The latter would result in faster dome growth. The pic comes from the archive.
Etna: Earthquake near crater
The Italian volcano Etna continues to be explosively active. The main scene of the action is the southeast crater. Here, glowing tephra rises up to 250 m above crater level. Strombolian eruptions are also observed from Voragine. A recent Sentinel satellite photo reveals 4 thermal anomalies in the summit area: the largest marks the southeast crater, then there are smaller anomalies in Bocca Nuova and in Voragine. Last, but not least, Northeast Crater is also emitting heat. MIROVA registered today a moderate thermal radiation with 22 MW power. Several earthquakes manifested themselves in the area of the summit. On the map they are marked in the northeast. If you look more closely, you can see a cluster of microquakes also south of the crater complex. The tremor is high and I expect more activity.
Hawaii: Earthquake Mb 4.7
Big Island Hawaii was shaken by a moderate earthquake of magnitude 4.7 (EMSC). The USGS gives a magnitude of 4.0. The depth of the earthquake focus was located at 35 km. The epicenter was located 10 km southeast of Pahala, in the area of the lower west rift. The quake occurred at 4:15 am UCT. During the morning, there were 5 more tremors in the 2 range.
A look at the map also reveals that there was a small earthquake swarm at Mauna Loa. The quakes manifested northeast of the caldera and also had magnitudes around 2. The hypocenters were at shallow depths.
Sulawesi: Earthquake Mw 6,4
Last night there was a strong earthquake on Sulawesi. According to EMSC, it had magnitude 6.4. USGS determined a magnitude of 6.2. The hypocenter was located at a depth of 10 km. The epicenter manifested itself again 34 km south of Mamuju. According to media reports, this time there was damage and at least 34 fatalities. This quake must not have been the last one, because especially on Sulawesi the stronger earthquakes like to come in series.
Merapi: Seismic drops off
Seismicity on Merapi has dropped sharply in the last two days. It halved from almost 400 daily quakes to less than 200 tremors. That still sounds like a lot, however, these are almost all rockfall signals that are being registered. Hybrid and volcanotectonic quakes were hardly detected. Just these quakes are caused by rising magma. So it could be that the magma ascent stopped and the current dome growth phase ends. The next few days will show whether the volcano is only taking a short breather or whether it will actually take a longer break.
Etna: High thermal signal
Sicilian Etna is very hot today, emitting heat with a power of 203 MW. Currently, on the thermalcam, you can see that a lot of glowing tephra is on the way on the eastern flank of the southeast crater cone. Strong strombolian eruptions from Southeast Crater were photographed again tonight. In addition, Voragine and Northeast Crater joined in. Such intense summit activity from multiple craters is not produced by Etna every day. Moreover, the activity could increase to a paroxysm. The tremor is on the border of the red zone. Seismicity is dominated by the shallow earthquakes east of the crater that I reported on yesterday. There seems to be some magma on the way here.
Merapi: Pyroclastic flow went off
A small pyroclastic flow went off at the Indonesian volcano Merapi yesterday. It generated a seismic signal of 120 seconds duration and with a maximum amplitude of 45 mm. Contrary to expectations, it did not flow over the southern flank, where the large vent is located, but over a field further west. This is where most of the pyroclastic flows from the 2006 eruption departed. Looking at satellite photos, one can see that steam is also rising from the northwest crater area; this is where the dome appears to be growing the most. The VAAC detected volcanic ash at 3000 m altitude. A total of 440 earthquakes were registered.
Kilauea: Lava lake rose
At Kilauea in Hawaii, the lava lake continues to be active and its level has risen. Latest measurements showed a depth of 192 m. Thus, it rose 2 m above its edge, which is defined by a crust of solidified lava. Accordingly, the deflation is increased. Its dimensions are 720×560 m. The lava lake is fed from 2 vents on the west wall. A hornito has formed on the upper one, which has continued to grow. The HVO describes that strombolian lava patterning is observed there. The lower vent is below the lake surface and produces much more lava. It produces a dome-like bulge in the lake surface. Seismicity is slightly elevated and tremors are recorded. Approximately 3500-6500 tons of sulfur dioxide are emitted daily. This is in the range of the 2018 lava lake. MIROVA registers very high thermal radiation. It is mostly above 2000 MW power.
Etna erupts permanent ash cloud
Etna in Sicily is perky this morning, erupting ash clouds from the southeast crater cone. Strong winds push the ash into the Valle del Bove. The action can be followed nicely on the live cams. Thermal imaging cameras show that incandescent cinders are also being produced. The tremor is still low and it does not look like it is the starting phase of a paroxysm. However, it cannot be ruled out that the activity will increase. Already at night the volcano was very active and produced strong strombolian eruptions from several craters.