EtnaUpdater @EtnaUpdater@qoto.org
Volcanophilic nerd & #volcano hiker blogging about Mt #Etna since 2004. Find tweets about Etna and also my backyard geology, the #Vogelsberg area.
Joined Nov 2022
Etna update, 21/05/2023
This morning, a paroxysm occurred at the Southeast Crater complex of Mt Etna. A lava fountain and a lava flow were released in a southerly direction. Ash rain fell in Adrano and Catania.
Torrential rains, stormy winds and dense clouds made it impossible to observe the summit region of Etna with webcams yesterday and today. The tremor, which also fluctuated at a high level yesterday, began to increase slowly at first from about 07:00 this morning. From about 08:00, the increase accelerated intensely and the tremor reached very high levels.
Unfortunately, none of the webcams allowed observation of the eruptive activity. However, around 12:40 p.m., the INGV webcam stationed in Catania showed ashfall. Ash and lapilli rains were also reported on social networks in various localities (e.g., Bronte, Adrano, Biancavilla). Around 11:30 a.m., the tremor decreased significantly and has been fluctuating at a medium level since then. Tonight it loosened up a bit and now glowing areas were visible via the webcams in the area between Monte Barbagallo and Monte Frumento Supino. This indicates that a lava flow has moved down the southern flank. During numerous previous paroxysmal phases of the Southeast Crater complex, most recently in February 2022, lava flows have already moved down here, released from the breach in the southern or southwestern flank of Southeast Crater. Also, via the Monte Cagliato thermal imager, the Southeast Crater complex was visible from the east for a very short time this evening. Here, at first glance, no new lava flows were visible, so the lava probably escaped only in a southerly direction.
Webcam photo by INGV - La Montagnola cam (S flank)
Etna update, 18/05/2023
Accompanied by earthquakes and a strong increase of the tremor, explosive activity started today in Bocca Nuova. In the meantime, the tremor has decreased again somewhat.
During the last 14 days, dense clouds, rain and fresh snow hindered the observation of Etna's summit region very often. During the cloud-free hours, the usual gas emissions appeared, which continued to be most vigorous at Bocca Nuova and often intensified in pulses.
At Voragine and Northeast Crater, I continued to observe no significant gas emissions. At the Southeast Crater complex, some gas was persistently emitted from the area of the central crater, between old and new Southeast Crater. Gas and white steam were also persistently emitted from the upper northern flank and the upper northeastern flank of New Southeast Crater.
On the morning of 14 May, a small explosive ash emission occurred at New Southeast Crater around 08:36. The starting point was apparently again a vent on the upper northeastern flank of the cone, which had already caused a similar explosion on 06 May. I could not observe further ash emissions there.
After a series of light earthquakes that occurred this morning between 03:00 and 09:00 on the eastern flank of Etna in the area of Acireale - Santa Venerina - Linera and in the Valle del Bove, respectively, the tremor began to increase significantly from about 12:00. However, bad weather with many clouds prevented the observations at first. Later, the weather cleared up a bit and now it became obvious that a lot of gas and steam was rising from Bocca Nuova. From about 17:00, a small thermal anomaly was also visible over the central crater cone via the thermal imaging camera in Bronte, suggesting the release of hot material from Bocca Nuova. Other thermal anomalies were visible until at least 20:00, but appeared weaker than before despite better weather.
In the meantime, INGV has confirmed the explosive activity in Bocca Nuova. It is reported that the explosive activity started around 17:00. No ash has been emitted so far. The increase in tremor has continued, according to INGV. The source of the tremor was located between Bocca Nuova and Southeast Crater at about 2500 m altitude. The explosive activity could also be detected by infrasound from 17:00. As further reported, a seismic crisis started around 16:45 in the summit area of Etna. The strongest quake was recorded at 17:00 with a magnitude of 1.9. Also starting at 16:45, the clinometric stations in the summit area of Etna showed a change of two microradians. Slightly weakened, this change was also visible at lower stations [1].
In the last two weeks, small signals reminiscent of explosion signals were visible on the online seismograms of station ECNE about every 30 minutes. Due to strong tremor, the online signals were overlaid by strong noise from about 12:00 on May 18.
The tremor had increased slightly on May 12, remained at a medium level, decreased again slightly from May 16, and then began to increase significantly on May 18 at about 12:00. The tremor reached the preliminary peak around 17:00, then it decreased slightly again [2].
On 10.05. several earthquakes occurred in the Linera - San Giovanni Bosco area (eastern flank), the strongest having a magnitude of 2.4. On 13.05. an earthquake with a magnitude of 2.0 was recorded southeast of Paternò (southern flank). On 17.05. an earthquake of magnitude 1.8 occurred southwest of Monte Scorsone (eastern flank). On 18.05. several earthquakes occurred at very shallow depths in the Santa Maria Ammalati - Mangano - Santa Tecla area (southeastern flank), with the strongest shaking reaching a magnitude of 3.2. On the same day, two earthquakes occurred at Linera (eastern flank), with magnitudes of 2.2 and 2.3, respectively. Also on 18.05., an earthquake of magnitude 2.0 occurred at Monte Centenari (eastern flank), followed by two earthquakes of magnitudes 1.7 and 1.9, respectively, northeast of Monte Frumento Supino (New Southeast Crater area) [3].
My interpretation of the data and speculations about the further development:
The earthquakes on the southeast and east flanks of Etna that occurred early this morning were probably the response of a north-south trending fault to magma ascent. The magma ascent later became noticeable by significant changes in tilt of slopes at the clinometric stations. The final ascent was then also signaled by sharply increasing tremor. Apparently, the magma then found its way into Bocca Nuova, which has at least one open vent. There, strombolian explosions probably then occurred, as thermal anomalies were recorded over the summit crater. Apart from the explosive activity in Bocca Nuova, today's events remind me of November 15, 2022, when, accompanied by some earthquakes, the inclination of the mountain also changed rapidly and intense tremors started. At that time, however, there was no eruptive activity at first. However, it occurred 12 days later in the form of purely effusive activity at the Southeast Crater Complex. This activity continued until February of this year.
I think it is possible that the Southeast Crater Complex will be active again this time. There were already several light earthquakes there this afternoon. It could be that strombolian activity is starting at one of the vents, perhaps even the one that produced the two explosive ash emissions. However, it is also quite possible that an eruptive fissure, preferably on the southeast or northeast flank, opens and prolonged effusive activity resumes.
Of course, continued strombolian activity in Bocca Nuova is also conceivable, but I rather suspect that only the overpressure has discharged here and that Bocca Nuova will continue to serve for the release of the gases of the rising magma. The gas-depleted magma then slowly rises and seeks a weak spot, which as already mentioned should be found at the Southeast Crater Complex, and then generates purely effusive and longer-lasting activity. But maybe something completely different happens, because the old lady is always good for a surprise!
1 - INGV-Sezione di Catania. 2023. 2023-05-18 15:43:49 - INVIO COMUNICATO GENERICO DI ATTIVITà VULCANICA
2 - INGV-Sezione di Catania. 2023. Home. TREMORE VULCANICO. ECNE
3 - INGV. Osservatorio Etneo. Sorveglianza e Monitoraggio. DATABASE TERREMOTI. Localizzazioni di sala operativa. 2023.
Webcam photo by INGV - Bronte thermal cam (W flank):
#Etna, 2016
An almost perfect ring of gas released from the Voragine, one of the summit craters of Mt Etna.
#Etna, 2007
A former house that was flooded by a lava flow in 1983. The house was excavated from the lava flow near Rifugio Sapienza.
Etna update, 07/05/2023
In the late evening of 06 May, a small explosive ash emission occurred on the upper eastern to northeastern flank of New Southeast Crater. On photos taken by INGV thermal imaging cameras, the explosion was visible as a small thermal anomaly around 23:25 (local time). Light-sensitive webcams also showed the explosive event. The explosion released a mushroom-shaped cloud of ash and steam that traveled in an easterly direction. After the event, pulsating glow could be seen on light-sensitive webcams for at least an hour. Escaping gas was apparently illuminated from below.
In the further course of the night and also today during the day I could not recognize any new explosive activity over the webcams. There was only increased gas or steam emitted from this area.
The increased gas emissions, as well as faint glow on the upper northeast flank had already been noticed since April 23.
The tremor did not increase before the explosion, but on the contrary was even slightly lower than on the previous days. It continues to fluctuate at a medium level [1].
1 - INGV-Sezione di Catania. 2023. Home. TREMORE VULCANICO. ECNE
Webcam photo by INGV - Piedimonte Etneo cam (NE flank).
#Stromboli, June 2008
Lava bombs ejected from the volcanic crater roll and bounce down the steep flank (Sciara del Fuoco) of the island of Stromboli. With each impact, they produce small clouds of dust. Then they plunge into the sea.
May 2009 - Mt Etna, Sicily
Since May 2008, Mt Etna has been producing lava from an eruptive fissure on its upper eastern flank. Temporary vents open again and again, squeezing out viscous lava like toothpaste.
July 2010 - Mt Etna, Sicily
The view goes down from the northwestern rim of the Central Crater cone to the vent of the Voragine. Behind it, you can see the strongly eroded boundary wall to Bocca Nuova, another summit crater of Etna. A lot of gas rises here.
March 2007 - Turrialba, Costa Rica
This volcano is the second highest volcano of Costa Rica with 3325 m height. The view goes from the central crater to the southwest. Behind the wall is the active crater, which showed first signs of awakening during my visit.
#LaPalma - #CanaryIslands 01/2004
View from the Cumbre Vieja to the Pico Bejenado and the Caldera de Taburiente.
Today my time travel on #throwbackthursday goes back to June 2008. I am on the island of Vulcano on the terrace of the Hotel Eolien and enjoy the sunset over the bay of Porto Ponente with antipasti and white wine. Simply dreamlike!
Etna update, 17/02/2023
During the past week, Mt Etna remained relatively quiet, with the usual gas releases from Bocca Nuova and the Southeast Crater complex. Deep-seated explosions probably occurred in Bocca Nuova. The tremor still remained somewhat elevated. Seismic activity, however, was low.
Last week, initially very bad weather with large amounts of snow and storms prevented the observation of Etna by webcams. Even after an improvement in the weather from 14 February, many cameras were still down. The available webcams showed that lava was still not being produced at the New Southeast Crater. There was continued emission of gas and steam in the summit area of the cone. During the nights, faint glow smoke was visible just below the northern rim of the crater. A fumarole field is located here, as well as fractures and a former vent that was active during the May/June 2022 eruption.
Otherwise, Bocca Nuova continued to release gas vigorously and in pulses. During the night of 16 February, faint glow was sporadically visible above the summit crater by means of light-sensitive webcams. Last night, the glow intensified and became more frequent. Probably deep-seated explosions occurred. I was still unable to detect any significant gas emission from the northeast crater and Voragine.
The evaluation of the data from the GPS stations showed no significant changes for the period between 06 and 12 February [1].
The clinometric data did not show any significant changes in the slope of the volcano building between 06 and 12 February [1].
The measurement of infrasound activity at the summit craters was strongly disturbed by very bad weather in the period from 06 to 12 February. Overall, there was a slight decrease in infrasound activity. The source of the events was Bocca Nuova [1].
Sulphur dioxide emissions at the summit craters increased somewhat in the period between 06.02. and 12.02. and were at a medium level.
Ground carbon dioxide emissions (ETNAGAS station) increased slightly between 06.02. and 12.02. and reached near-medium levels [1].
The online seismograms of station ECNE showed only single weak signals last week, after initial interruption due to bad weather [2].
The tremor fluctuated on the border between low and medium level during the past week [2].
On 13.02., a quake of magnitude 1.9 was measured south of Monte San Leo (southern flank) [3].
My interpretation of the data and speculations about the further development:
So now the effusive activity at the northeastern base of New Southeast Crater, which started at the end of November 2022, has come to an end again. This was already indicated from mid-January, when the production rate began to show greater fluctuations. A total of about 6 million m3 of lava was produced, which is a relatively small amount in comparison. Analyses of the lava produced in December showed that it was more highly developed material, which was also evident from the low explosive activity. The magma had probably been stored in the mountain for some time and was able to degas via the summit craters. Then it found an outlet at the end of November and an eruption occurred. Probably also because the mountain slowly expanded due to the rising magma and probably more magma rose than could be stored within the volcanic structure. The still high readings for the helium 4 isotope show, in my opinion, that there is still plenty of fresh magma flowing in under the mountain. A small part of it will probably continue to rise in the mountain and sooner or later lead to new eruptive activity. It is not yet possible to say what this will look like. It is quite possible that the quiet eruptive activity of last winter will be repeated in a few months. However, if more gas is involved or if this has no possibility of degassing, there may also be strombolian explosions at the Southeast Crater complex. A new phase of paroxysmal eruptions cannot be completely ruled out either. So let's just be surprised what the old lady has in store for us this time!
1 - INGV-Sezione di Catania. 2023. Etna - BOLLETTINO SETTIMANALE - SETTIMANA DI RIFERIMENTO 06/02/2023 - 12/02/2023
2 - INGV-Sezione di Catania. 2023. Home. TREMORE VULCANICO. ECNE
3 - INGV. Osservatorio Etneo. Sorveglianza e Monitoraggio. DATABASE TERREMOTI. Localizzazioni di sala operativa. 2023.
#Etna #eruption #volcano #lava
Photo by INGV Catania
Today, my time travel on #throwbackthursday takes me back to 2008, to a holiday I spent on the Aeolian Islands, north of Sicily. The photo shows the crater "Grand Cratere" on the island of Vulcano. In the background you can see the northern part of the island with the cone of Vulcanello. Behind it are the islands of Lipari and Salina.
At the eruptive fissure of 2008, Mt Etna May 2009
Once again, I look back at an interesting stay on Mt Etna on #throwbackthursday. On the afternoon of 01 August 2012, I climbed the summit craters, where strombolian explosions had been occurring in the Bocca Nuova since the beginning of July. I stayed until nightfall and was able to take great photos of the activity.
Ice and ash, Mt Etna May 2009
Today, once again a photo for #VolcanoMonday :
It shows the 3432 m high Irazu in Costa Rica. It contains an acid lake and is considered one of the most dangerous volcanoes in the country. It is one of Costa Rica's "drive in volcanoes", as a well-built road leads up to its summit. I took the photo in March 2007.
Volcanophilic nerd & #volcano hiker blogging about Mt #Etna since 2004. Find tweets about Etna and also my backyard geology, the #Vogelsberg area.
Joined Nov 2022
