The Ecuadorian volcano Sangay is still active. Today, explosive eruptions were detected, which caused volcanic ash to rise to an altitude of 6400 m. The ash was drifted westward. In a special report of the IGEPN the morphological changes of the volcano caused by the eruptions were investigated. Most striking is a depression on the southeast flank. It was carved into the flank by lava flows, debris avalanches and pyroclastic flows. The gorge is almost 400 m wide, 4 km long and starts from the crater. Three thermal anomalies have been detected in it. 2 of the anomalies are located in the upper part of the canyon. The top anomaly is in the crater area and marks an explosive vent. The 2nd anomaly is below the base of the crater and represents the source of the lava flows. The 3rd heat source is located in the lower part of the gorge and is probably generated by an accumulation of hot deposits of pyroclastic flows.
The seismic crisis started on July 3, 2020 at 07:20 local time and ended around 08:00 local time. This episode was accompanied by surface deformations which remained extremely weak and localized at the top of the Piton de la Fournaise. Since then, no resumption of seismic activity or deformation has been observed.
Several hours without any activity being observed are evidence of the deep stop of magma in the building.
Nevertheless, given the resumption of inflation observed since June 16, a medium-term eruption cannot be ruled out.
Close to the Mexican capital the Popocatepetl is still active. Yesterday the CENAPRED Institute published a very atmospheric photo of a sunset eruption. Besides the explosion, 169 ash-steam exhalations and 32 minutes of tremors were recorded. Today, explosive volcanic eruptions were also recorded: the VAAC issued 2 VONA messages according to which volcanic ash had risen to an altitude of 5800 m.
Popocatepetl has become a permanently active volcano in recent years. Only seldom there are longer pauses in eruption. In addition a lava dome grows sporadically in the crater. The ascent is prohibited.
On the Indonesian website krjogja.com it is reported that the Merapi has entered a new phase with dome growth. This information comes from Agus Budi Santoso, the head of the Merapi Volcano section at the BPPTKG. The new intrusion is the 7th phase since the beginning of the eruption and is accompanied by explosive activity and deep seismic. The larger eruptions in the first half of the year would have more than halved the volume of the lava dome to 200,000 cubic metres. Now it looks as if the dome is getting bigger again, increasing the potential danger.
The Japanese island volcano Nishinoshima continues to make headlines. The VAAC issued numerous VONA warnings of ash clouds. Currently volcanic ash is registered at an altitude of 7300 m above sea level. Since the cinder cone is only a few 100 m high, this represents a remarkably large eruption cloud. The peak value yesterday was 4200 m and was described in Japanese media as the highest ash cloud since the beginning of the eruption. The thermal radiation yesterday had a power of 1860 MW and is therefore also in a very high range. So lava flows are still being produced, which will change the face of the island forever. Nishinoshima is growing and growing. Radar images show that not only the coastline is constantly shifting, but also the cinder cone with the explosive crater is subject to major changes. It looks as if a major collapse has occurred in the south of the cone. Probably the collapse was caused by a new lava flow.
The Icelandic volcanologists of the Institute IMO express concern about the current situation on the Reykjanes Peninsula. In the vicinity of Grindavik, there have been repeated swarm quakes in recent months, which were quite strong. Since 21 January, GPS measurements now show a rise in the ground that has not been seen there for decades. Under the volcano Þorbjörn the ground is rising by 3-4 mm per day. This rise is caused by magmatic fluids rising under the volcano. In all probability it is magma that causes Þorbjörn to rise. As a result, the civil defence has declared the VONA warning level “yellow”. Residents of the area will be invited to an information meeting tomorrow. There they will be informed about how to prepare for a possible volcanic eruption.
While all eyes look at the Philippine Taal volcano, there is also something interesting going on under the European pedant Campi Flegrei. The INGV Napoli yesterday published a new report on the situation of the large caldera volcano, which can erupt at a similar rate as the Taal. The focus of the report is the thermal area around the fumarole of Pisciarelli , which is located on the north-western crater rim of the Solfatara. There one can observe an increase in the tremor amplitude. Although it is primarily a fumarolic tremor, which occurs at a depth of less than 1 km and is therefore in the area of the hydrothermal system, it also represents the overall state of the magmatic system of the caldera. The volcanologists see a correlation between changes in the geochemistry of the fluids, the soil deformation with peaks of 60 cm uplift and the fumarolic tremor. Therefore, it is quite possible that the Caldera volcano is slowly preparing for an eruption.
The situation on the Taal is still exciting. Yesterday and today the VAAC registered one ash cloud each, whose ascent heights could not be determined. The seismic activity is still high. The Taal network recorded 486 tremors in the last 24 hours. The strongest one had a magnitude of 2.7 and was not noticed by local residents. The seismic activity is probably caused by rising magma. The ground deformations are correspondingly large. Especially in the southwest and north of the caldera there are ground elevations which are probably related to the inflation of magmatic fluids. In the eastern part of the caldera, however, the ground has been sinking.
Sulphur dioxide emissions are disproportionately low, at only 224 tonnes per day. One would expect at least 10 times the current value. Philippine volcanologists speculate about plugs in the production vents that prevent the gas from escaping. However, such plugs would not only block the sulphur dioxide, but also impair the entire gas exchange. The result would be an enormous increase in pressure in the earth’s interior. Alternatively, the soil deformations could not be caused by magma, but by other fluids. Water would be one possibility. This would also be an answer to the question where the disappeared water of Lake Taal has gone: Last week the lake level dropped a few centimetres.
The activity of the volcano Etna on Sicily (Italy) continues and is even worth seeing, as the video below demonstrates. The intracrater cone of Voragine is strombolian active and continues to grow slowly. From a vent on the lower flank of the cone a lava flow is flowing, which splits into 2 arms. They flow into the neighbouring crater Bocca Nuova and form a rare lava fall there.
From the technical point of view the eruption manifests itself in an increased tremor and moderate thermal signals. MIROVA registered radiation with a power of 44 MW. In addition, the INGV thermal imaging camera now shows 2 hot spots in the area of the New South East Crater. It looks as if another vent has become active there.
On 12 January, the eruption began with phreatic explosions, which then increased rapidly. A violent eruption caused ash clouds to rise into the stratosphere. The eruptions manifested from the main crater of Volcano Island, which is located in the middle of the Taal caldera. The ash not only rained down in the immediate vicinity of the volcano, but even reached the capital Manila. The airport was closed.
In various places, house roofs collapsed, which could not withstand the weight of the ash. The following day, lateral vents opened on the flank of Volcano Island. These generate smaller eruptions. PHILVOLCS also reported short lava flows of highly viscous lava.
The eruption was announced by numerous earthquakes. Their frequency increased in the last weeks and reached peak values of 140 quakes per day. Shortly before the eruption the magnitude of the earthquakes increased and reached M 4.0.
The authorities reacted quickly and ordered evacuations. A 14 km long exclusion zone was established. It largely encloses the Taal Lake, which is located in the caldera.
Translated with www.DeepL.com/Translator (free version)