And once again, my time travel on #throwbackthursday goes back to an eruption of Mt Etna. This one started in May 2008 and ended in July 2009. In June/July 2008 I was able to visit the eruption site several times. The photo was taken in the early morning of 01/07/2008 and shows the lava streams flowing into the large uninhabited valley Valle del Bove. In the background you can see the lights of some villages along the east coast of Sicily.
Etna update, 23.12.2022:
During the past 14 days, the eruption at the base of New Southeast Crater has continued. The lava flow has increased significantly in length over the last few days and is on its way to the Valle del Bove. The tremor remained elevated and gas emissions at the summit craters have also increased.
In the last two weeks, clouds often hindered the observation of Etna's summit area by webcams. At times, however, gaps in the clouds allowed a view of the eruptive activity. During the past 14 days, lava emission continued at the northeastern base of New Southeast Crater. The lava flow continued to move in a northeasterly to northerly direction and poured into the Valle del Leone. Its front continued to advance in a northerly direction. From 15 December onwards, it reached the bottom of the Valle del Leone at an altitude of about 2500 - 2600 metres. In the following days, it crossed the shallowly sloping valley floor and slowly approached the edge of the Valle del Bove. On 21 December, the lava began to flow down the steep slope of the Valle del Bove. By the evening of 23 December, the front had reached about 2200 m high terrain and was located southwest of Monte Simone.
In the meantime, below the effusive vent, a fan-shaped lava field developed consisting of several narrow flows that kept changing their position slightly.
Furthermore, I did not observe any explosive activity at the effusive vent or at the South East Crater complex. In the summit area of New Southeast Crater, only fumaroles continued to release gas.
Meanwhile, Bocca Nuova experienced vigorous and often pulsating gas emission. Hardly any gas emission was visible at Northeast Crater and Voragine.
As the INGV reports, hornitos have developed above the effusive vents. At times, there is also weak explosive activity there associated with the ejection of incandescent lava fragments. Within the lava field, some temporary vents have formed, feeding narrow lava flows. Using MODIS/VIIRS satellite data, the volume of lava released so far has been estimated at 500,000 - 1,000,000 m3 [1].
The evaluation of the data from the GPS stations showed further inflation of the volcano structure in the last 7 days, which was recorded in particular by the stations on the central western flank. In contrast, the stations in the summit region did not record any significant changes [1].
The clinometric data did not show any significant changes regarding the slope on the mountain flanks during the past week [1].
Infrasound activity at the summit craters was weak to moderate in the period from 07 to 18 December. Most of the events were registered on 18 December, although the measurements were disturbed by strong winds on some days. The source of the activity was Bocca Nuova [1].
Sulphur dioxide emissions from the summit craters continued to increase between 6 and 18 December. The daily emission rates reached high levels.
Ground carbon dioxide emissions (ETNAGAS station) remained at a medium level between 06 and 18 December [1].
The online seismograms of station ECNE were overlaid by noise during the past week, which was caused by the persistently increased tremor [2].
The tremor has been at a medium level for the last 14 days, with only slight fluctuations. Most recently, there was a slight upward trend [2].
The source of the tremor was in the area between the southeast crater and Bocca Nuova at an altitude of between 2000 and 2800 m. In addition, a narrow tremor track in a westerly to southwesterly direction was observed, leading up to an altitude of about 2500 m - 2750 m and ending in the region above the Galvarina area [1].
On 18.12. a quake of magnitude 1.8 was registered west of Monte Parmentelli (southwest flank). On 18.12. two quakes occurred west of Moio Alcantara (north flank), the strongest having a magnitude of 1.6. On 19.12. an earthquake of magnitude 2.3 was recorded at Monte Zoccolaro (southeast flank). On 21.12. a quake with a magnitude of 1.6 occurred north of Monte Centenari (eastern flank) [3].
My interpretation of the data and speculations about the further development:
Interesting in the tremor data is a track that leads from the depth of the mountain in a southwesterly to westerly direction and ends at an altitude of approx. 2500 - 2750 m. It almost looks as if magma rose in this area, but then did not make it to the earth's surface. Unfortunately, the INGV does not refer to this measurement data in the report, so it remains unclear what really happened there. Otherwise, the second week of December showed a further increase in sulphur dioxide emissions at the summit craters, which indicates that more magma was degassing than in the weeks before. Certainly, only part of the rising magma is being released by the current eruption, as the inflation of the volcanic edifice has also continued to increase. Thus, a continuation of the effusive activity at the New Southeast Crater can be expected in the next days to weeks.
1 - INGV-Sezione di Catania. 2022. Etna - BOLLETTINO SETTIMANALE - SETTIMANA DI RIFERIMENTO 12/12/2022 - 18/12/2022
2 - INGV-Sezione di Catania. 2022. Home. TREMORE VULCANICO. ECNE
3 - INGV. Osservatorio Etneo. Sorveglianza e Monitoraggio. DATABASE TERREMOTI. Localizzazioni di sala operativa. 2022.
Photo by INGV
Today, on #throwbackthursday my time travel goes back to an eruption of Mt Etna. I was lucky enough to be present during its start.
The photo shows two vents below Northeast Crater and was taken on 07 July 2014. A spiky cone of welded lava has formed around one vent, which not only ejects some glowing lava fragments but also releases a lava flow. The other vent has not yet formed a cone and generates loud detonations from time to time, ejecting larger lava fragments. The white chunks lying between the vents are interesting. These are blocks of ice that where apparently ejected when the vents had opened. This eruption generated several cinder cones that are still visible today. It ended on 09.08.2014.
In the rainforest in Costa Rica near the Arenal Volcano.
Here a video of the current eruption at Mt Etna by Active Nature "Michele Mammino"...
Bubbling mud pots at the base of the Rincón de la Vieja volcano in Costa Rica.
#Photomonday #VolcanoMonday #Photo #Fotomontag
Etna update, 16.12.2022:
During the past week, clouds have often hampered webcam observations of Mount Etna's summit area. At times, however, gaps in the clouds also allowed a view of the eruptive events.
During the past 7 days, lava emission has continued at the northeast base of the New Southeast Crater. The lava flow continued to move in a northeasterly to northerly direction and poured into the Valle del Leone. The front advanced a little further in a northerly direction. From December 15th it reached the valley floor of the Valle del Leone at an altitude of approx. 2500 - 2600 m. Meanwhile, below the effusive vent, a fan-shaped lava field has developed. Several narrow streams moving in this field and keep changing their position slightly.
Furthermore, I could not observe explosive activity either at the effusive vent or at the Southeast Crater complex. In the summit area of the New South East crater only fumaroles continuously released gas.
Meanwhile, in the Bocca Nuova there was strong and often pulse-like increased gas emission. Only weak gas emission was visvile at NE Crater and Voragine.
During the last 7 days the tremor was at an average level and showed only minor fluctuations [1].
[1] INGV-Sezione di Catania. 2022. Home. TREMORE VULCANICO. ECNE
Crystals of sulphur, gypsum and various sulphates at a fumarole on the crater Fossa Grande on the island of Vulcano (Italy).
#VolcanoMonday #Photomonday #Fotomontag #Photo #Foto #Vulcano #volcano
Etna update, 09.12.22:
Effusive activity at the northeastern base of New Southeast Crater continued last week. While the tremor remained elevated, seismic activity increased slightly.
Effusive activity continued at the northeast base of New Southeast Crater last week. The released lava flow, which remained relatively narrow, continued to move into the Valle del Leone, reaching a length of about 600 m on 08 December. Meanwhile, some gas was persistently emitted in the summit area of the New Southeast Crater. I could not observe any explosive activity. Light sensitive webcams sometimes showed faint glow on the upper northern flank of the cone, where an explosive vent was active in May/June.
Bocca Nuova continued to release gas in pulses during the last week. At Voragine and Northeast Crater there was only minor gas emission.
The INGV reports that the effusive vent, which opened on 30 November, is located at an altitude of 2900 metres. The lava flow released by the vent moved parallel to the lava flow emitted from 27 November and had a length of 450 m on 30 November. Its front moved on 2700 m high terrain [1].
The analysis of the data from the GPS stations showed the continuation of the inflation of the volcanic edifice in November [1].
The clinometric data showed a rapid change in the slope in the summit area of one microradian on 15 September [1].
Infrasound activity at the summit craters was moderate in November and the amplitudes of the events were low. The source of the activity was Bocca Nuova [1].
Sulphur dioxide emissions at the summit craters increased somewhat in November. The mean emission rate reached average levels.
Ground carbon dioxide emissions (ETNAGAS station) were at average levels in November.
The concentration of helium isotopes (3He/4He ratio) in the Etna area, which was last determined on 24 November, was lower than in the previous month with a value of 0.57 and was at an average level [1].
The online seismograms of the ECNE station were characterised by slight noise during the past week due to the increased tremor. Weak long-period signals were frequently observed.
The tremor was at a medium level last week and was subject to only slight fluctuations [2].
On 02.12. and 03.12. two weak quakes occurred near Sant'Alfio (eastern flank), the strongest having a magnitude of 1.6. On 07.12. two quakes occurred east of Sant'Alfio, with magnitudes of 2.5 and 1.4. On 08.12. an earthquake of magnitude 2.5 was registered south of Paternò (southern flank). On 08.12. an earthquake with a magnitude of 1.5 occurred near Mangano (eastern flank) [3].
My interpretation of the data and speculation about further developments:
The slight increase in seismic activity, which had recently been particularly concentrated on the eastern flank of Etna, as well as the continuation of the inflation of the volcanic edifice indicate, in my opinion, that magma continues to be stored in the mountain. The relatively weak effusive activity that has continued over the past week is unlikely to provide much relief in this regard.
Most of the gas from the rising magma is likely to escape via Bocca Nuova. As long as there is not a large amount of fresh magma rising, I do not expect explosive activity at the South East Crater complex.
Therefore, I think it is most likely that the purely effusive activity at the New South East Crater will continue. However, new vents could open further north or east at any time. A reduction of the effusive activity or a slow cessation of the eruption is also possible.
1 - INGV-Sezione di Catania. 2022. Etna - BOLLETTINO MENSILE MESE DI RIFERIMENTO NOVEMBRE 2022
2 - INGV-Sezione di Catania. 2022. Home. TREMORE VULCANICO. ECNE
3 - INGV. Osservatorio Etneo. Sorveglianza e Monitoraggio. DATABASE TERREMOTI. Localizzazioni di sala operativa. 2022.
Today, I look back to 15 July 2006, the day when a new eruption of Mt Etna startet after almost two years of quiescence. And it was just on this day that I arrived for a short holiday on the mountain and was able to observe an eruption at close range for the first time. The lava. The smell. The sound. Oh, what a day!
Etna update, 02.12.2022:
Since 27 November, lava has been erupting from the north-eastern base of the New Southeast Crater. This forms a short and narrow flow that is heading towards Valle del Leone. The tremor was temporarily increased and seismic activity is slightly enhanced.
Bad weather with fresh snow frequently hindered observations of the summit craters via webcams during the last 14 days. During the few cloud-free hours, Bocca Nuova continued to show the usual gas emissions, which were still strong and mostly intensified in pulses.
At Voragine and Northeast Crater, no significant gas releases were visible.
At the Southeast Crater complex, some gas was persistently emitted from the central area between the new and old Southeast Crater. In the northern summit area, fumaroles continuously released some gas.
After a stormy and cloudy day, the clouds slowly cleared on the evening of 27 November around 17:30 and suddenly a small thermal anomaly was visible on the Cagliato thermal cam. This was localised at the northeastern base of the New Southeast Crater. A little later, other webcams also showed several small glowing spots in this area, which is located at about 2800 m altitude. In the course of the evening, the glow intensified a bit more and a short lava flow was visible, slowly moving north/northeast towards the Valle del Leone. On the other hand, I was not able to see any glow in the summit area of the New Southeast Crater, but the cone was also often hidden in clouds.
During the night of 28 November, the lava emission continued, but the lava flow hardly progressed. On the morning of 28 November, around 06:30, only a little glow could be seen at the effusive vent. Later, clouds moved in and lingered until 29 November. However, no more activity was visible through some gaps in the clouds.
In the evening of 29 November, glow was again visible at the northeastern base of the New Southeast Crater from about 19:30. The Cagliato thermal camera also showed a small thermal anomaly a little later. Again, lava poured towards the Valle del Leone. In contrast to the eruptive event of 27 November, this time the tremor also increased significantly and reached almost high levels. The effusive vent was located slightly more slope upwards on the NE flank of the New Southeast Crater than during the 27 November eruption.
During the night of 30 November, lava emission continued, but the lava flow gained length very slowly. After the clouds cleared in the evening of 30 November, the northeastern base of the New Southeast Crater continued to show glowing spots. Effusive activity continued on 01 and 02 December. Meanwhile, only gas was emitted from the summit area of the New Southeast Crater. Explosive activity could not be detected.
On 30 November, INGV reported that the lava flow at the New Southeast Crater had reached a few hundred metres in length. Furthermore, it was reported that the source of the tremor was located between Southeast Crater and Bocca Nuova at an altitude of 2000 - 2600 m. Infrasound activity at the summit craters was low and concentrated at Bocca Nuova. No noticeable ground deformations were recorded at the volcanic edifice [1].
The tremor fluctuated at a medium level until 29 November, reaching nearly high levels only on 19 and 27 November. On 29 November, tremor began to rise rapidly and remained just at a high level until 30 November. Afterwards, the tremor oscillated between medium and high intensity several times and stabilised at medium level from 01 December [2].
On 19.11. a quake of magnitude 1.5 occurred east of Monte Nero (NE flank). On 19.11. a quake of magnitude 1.6 was measured northwest of Piano Pernicana (NE flank). On 25.11. two quakes occurred in Piano Pernicana, reaching magnitudes of 1.7 and 1.9 respectively. On 25.11. a quake of magnitude 2.1 occurred west of Randazzo (NW flank). On 28.11. a quake of magnitude 1.5 was recorded near Randazzo [3].
My interpretation of the data and speculations about the further development:
Now the magma has managed to make its way to the surface of Etna after all. After the presumed magma rise on 15 November, which I speculated about in my last update, the pressure in the mountain must have become a bit too great. Since the lava seems to flow out very quietly and there has been no explosive activity in the summit area of the Southeast Crater complex so far, it is probably already relatively strongly degassed magma. It has probably been rising for months (since the end of the last eruption in June) and is being degassed via Bocca Nuova. The recent increase in seismic activity, especially in the area of the Pernicana fault, may indicate that magma has accumulated in the area to the east of the summit craters and/or beneath the northeastern rift system. This has now created a path upwards and is likely to emerge until the pressure inside the mountain is equalised again. Since the vent is still relatively far up and will not be very large, I do not think a prolonged eruption is to be expected. However, it could happen that new effusive vents open further north or northeast, which would then also be located on somewhat lower altitude. Then a longer eruption is also conceivable. Of course, the magma rise can intensify at any time, or fresh and gas-rich magma can ascend. This would be a game changer. At the moment, however, there are no indications of this.
So I think it is most likely that the quiet and low lava production will continue for a few more days and that the narrow lava flow will gradually pour into the Valle del Leone.
[1] INGV-Sezione di Catania. 2022. Comunicati attività vulcanica. 30/11/2022 12:56 - COMUNICATO ETNA
[2] INGV-Sezione di Catania. 2022. Home. TREMORE VULCANICO. ECNE
[3] INGV. Osservatorio Etneo. Sorveglianza e Monitoraggio. DATABASE TERREMOTI. Localizzazioni di sala operativa. 2022.
Check out the new USGS webcam pointed towards Fissure 3 on #MaunaLoa: https://www.usgs.gov/media/webcams/m5cam-mauna-loa-fissure-3-eruption-northeast-rift-zone #volcano #eruption #Hawaii
Renewed eruptive activity at Mt Etna:
On the evening of 29.11.2022, the INGV webcams showed the production of lava at the northeastern base of the New Southeast Crater from about 18:30 UTC. The emission of lava in this area, located at an altitude of about 2800 m, had already started on the evening of 27 November, but then stopped again on 28 November. This time, the event was also associated with a significant intensification of the tremor, which reached almost high levels.
At 20:15 UTC, lava production continues and a short, narrow lava flow moves northwards towards Val del Leone.
Source: My own observations via webcams/website INGV
Here is a photo that I took on 07.07.2021 showing a short but very violent eruption (paroxysm) of Mt Etna's South East Crater.
#volcan #volcano #Etna Un petit évent éruptif s'est ouvert le 27 novembre au soir, vers 18h15 (heure locale), à l base du versant nord-est du Cône Sud-Est. Une petite coulée de lave a été produite/A small éruptive vent opened on the evening of 27/11, at the north-east foot of the South-East Cone, with formation of a small lava flow
Volcanophilic nerd & #volcano hiker blogging about Mt #Etna since 2004. Find tweets about Etna and also my backyard geology, the #Vogelsberg area.