In Sicily, Etna is still active and emits volcanic ash. Strong wind pushes the ash down and blows it into the Valle del Bove, which is located in the east of the volcano. The tremor fluctuates strongly and moves in medial-high spheres. Earthquake activity has not been particularly high in the last 2 days. However, several weak earthquakes occurred below the central crater area on August 14th. It should be noted that the INGV often reports earthquakes with a 1-2 day delay. On the thermal cam you can see that not only the saddle vent of the New South East Crater cone is involved – from which the volcanic ash is emitted – but also the actual main crater of the NSEC. A weak thermal signal is emitted from it and it looks as if hot volcanic scoria or hot fumaroles have been deposited at the crater rim.
Marc Szeglat
Kadovar emits ash
In Papua New Guinea the Kadovar volcano has become more active again. The small island volcano emits volcanic ash, which rises to an altitude of 1500 m. The volcano has been active again and again since January 2018, with major eruptions that changed the face of the island. For example, a lava dome grew on the east coast, which caused concern that it might collapse, causing a tsunami. Also this year, there were some bigger eruptions, but most of them took place under exclusion of the world public. Before the eruptions began, there was a small settlement on Kadovar. This was abandoned in the meantime and the inhabitants were resettled.
Bali: Earthquake south of the island
Yesterday an earthquake of magnitude 5.1 manifested itself off the southern coast of the Indonesian islands of Bali and Java, with the hypocenter at a depth of 56 km. The earthquake triggered a series of aftershocks, which were at a much lower depth of 10 km. Most of the aftershocks have magnitudes in the range of 3. The earthquakes are associated with the subduction along the Sundab Arc and are not directly related to the volcanism in the region.
A few hundred kilometres further east, similar events occurred in the Sumbawa region. Here, too, numerous earthquakes reduce stresses in the earth’s crust, which are caused by subduction along the Sunda Arc. It can be assumed that there are also tensions in the area between these two spots waiting to be relieved. At any time strong earthquakes can occur at the Sunda Arc, which could even trigger tsunamis.
Etna is getting hotter
After ash emissions stopped yesterday afternoon, the volcano has resumed its activity today. Indeed, on the thermal cam you can see that the area around the saddle vent is hot and glowing tephra is being extracted. Ash is caught by the strong wind, pressed down and transported towards the northeast. The tremor fluctuates strongly at the border to the “red area”. The LGS maintains the pre-warning level “orange”. It already indicated an increase in activity 3 days ago. Under the Valle del Bove the number of weak earthquakes increased slightly again. Earthquake activity below the summit crater is unremarkable.
Sinabung erupted
On the Indonesian island of Sumatra the Sinabung erupted again. The VAAC Darwin published a VONA message, after which volcanic ash rose to a height of 9800 m. The cloud drifted in a westerly direction. In time a second cloud reached a height of 4200 m and was multiplied in eastern direction.
The volcanologists of Magma/VSI registered increased seismic activity the day before. Among the signals was a Tornillo. They detected the eruption in 2 signals with maximum amplitudes of 120 mm and 1785-2246 seconds duration. Although the eruption cloud rose higher than during the last eruption, there must not have been a much higher energy behind it. Weaker winds may have favoured the vertical rise of the volcanic ash to higher altitudes. The seismic signals indicate an eruption similar to the one on 8 August. In fact, the main eruption lasted longer than now.
The seismicity was increased in the first quarter of the day. There were 19 volcano-tectonic tremors recorded. Another Tornillo was also recorded. Tremor also occurred. In fact, it looks like the sinking has entered a new eruptive phase.
Erupsi #Sinabung 10 Agustus 2020 10.16WIB https://t.co/TuGNOVdDhe pic.twitter.com/EcTnTeSzxF
— MAGMA Indonesia (@id_magma) August 10, 2020
Iceland: inflation confirmed
The IMO confirmed the presumed inflation in the earthquake zone near the Fagradalsfjall volcano on the Reykjanes peninsula. The ground elevation has been 3 cm since the beginning of the swarm earthquake on 18 July. The magma inflation was detected by INSAR satellite images. The deformation took place mainly during the main phase of the quake activity between July 18th and 20th. The magma penetrated into a northeast-southwest striking fault zone, which was already discovered in 2017, when swarm quakes also occurred there. The deformation is considered part of a larger volcanic-tectonic reactivation event on the Reykjanes Peninsula. This not only results in ground uplift, but also in subsidence. Such subsidence has now been discovered in the area of the Svartsengi geothermal power plant. It started 2 days before the swarm earthquake at Fagradalsfjall and was probably caused by the underground run-off of magmatic fluids.
USA-Alaska: Earthquake Mw 7,8
This morning a strong earthquake of magnitude 7.8 manifested itself off the coast of Alaska. The hypocenter was at a depth of 17 kilometers. The epicenter was located 84 kilometers south of Perryville. A tsunami alarm was sounded. People on the coast of Alaska and the Aleutian Islands were asked to go to higher ground. The data is from the EMSC and may still be subject to change.
Strong earthquakes could effect nearby volcanoes. A few kilometers north of Pennyville is Mount Veniaminof. The volcanoes Mount Pavlof and Mount Chiginagak are also located around the epicenter.
Raung with Hotspot
The volcano Raung is located in the east of the Indonesian island of Java and has been under special observation by local volcanologists for several days. Seismic signals signalled the awakening of the volcano. Small ash clouds were also sighted rising above the crater rim. Now there is a further indication of the increasing activity of the volcano: the sentinel satellites detected a heat source. It emits radiation with a power of 33 MW and is located at the northern rim of the small crater that had formed in the caldera in 2015. The crater is part of an intra-caldera cinder cone. The evidence suggests strombolian activity. Visual observations of the crater rim have not been reported to me. Raung is part of the Ijen volcanic massif, which also includes the better known sulfur-producing Kawah Ijen.
Iceland: Strong earthquake swarm on Reykjanes
The Icelandic peninsula of Reykjanes is again hit by a strong Earthquake swarm. The strongest single quake had a magnitude of 5.0 and manifested itself 1.6 km northwest of Fagradalsfjall, with a hypocentre at 10 km depth. Fagradalsfjall is the highest elevation on Reykjanes with a height of 385 m and lies east of Grindavik. In the end, the epicentre of seismic activity shifted a little to the east, starting from the quake spot north of Grindavik where most of the previous earthquakes occurred.
IMO recorded a total of 936 earth tremors in the Reykjanes area in the last 48 hours. 16 quakes had magnitudes greater than 3, some of them even stronger than M 4.0. I assume that the quakes are related to further magma intrusion. However, an IMO report on this is still pending. However, the Icelandic Meteorological Authority reports that the stronger earth quakes were felt in the southwest of Iceland.
Stromboli: Another strong explosion
The Italian volcano Stromboli once again proved its unpredictability tonight and erupted a large amount of tephra at 3 o’clock, which covered the entire summit area with glowing bombs. On the video embedded below you can see that it was a short eruption phase with 4 explosions. At least 2 winding vents were involved in the explosions. Such unusually strong eruptions occurred in the past and cost the lives of several volcano observers. This time, however, no people should have been in the summit area, because the ascent was still blocked. Local residents report that they were woken up by a loud bang. However, no material fell in the lower part of the volcano. The eruption was weaker than on 3 July last year.
Unlike last year’s two eruptions, there was no longer period of increased activity before. On the contrary, the eruptions of the past days were comparatively weak. Only a few hours before, the strombolian eruptions increased significantly. Images of these were shared in our FB group “volcanoes and volcanism“. The only indicator for magma rise was an increased carbon dioxide emission: in the last two days the daily production increased from less than 200 tons to almost 1000 tons. Already at the end of June there were 2 measurements of more than 1000 tons per day.