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
At the eruptive fissure of 2008, Mt Etna May 2009
Etna update, 27/01/2023
During past week, lava continued to be released at the northeast base of Mt Etna's New Southeast Crater, but the production rate was subject to strong fluctuations. Tremor and seismic activity remained inconspicuous.
After the mountain had been completely wrapped in clouds all day on 22 January, the Monte Cagliato thermal camera showed a significant weakening of the lava flow on 23 January. This had previously been released from the effusive vent at the northeast base of New Southeast Crater in an easterly direction. Only some spots of the flow, which had previously stagnated at the base of the steep western wall of Valle del Bove, were still hot. Then, on the morning of 24 January, a new powerful thermal anomaly appeared just below the effusive vent. It was caused by a new gush of lava that poured eastwards again over the meanwhile cooling flow of the previous days. The new lava flow progressed slowly and on the morning of 25 January its front stagnated at the edge of the Valle del Bove, above the escarpment. Later, clouds moved in again and hid the mountain until the morning of 26 January. Through gaps in the clouds it was visible that the flow continued to stagnate and had even weakened somewhat compared to the previous day. In the evening of 26 January, the thermal anomalies below the effusive vent intensified and again a surge of fresh lava started moving eastwards. During the previous night, this flow then moved down the steep western wall of the Valle del Bove and reached about 2300 m high terrain in the morning. As the day progressed, however, the front stagnated again and this evening the lava flow did not look quite as well fed as yesterday.
At the summit craters, Bocca Nuova again showed the most gas emission last week, which was still frequently intensified in a pulse-like manner. Voragine and Northeast Crater continued to release only few amounts of gas. At the New Southeast Crater, gas was persistently emitted from the summit area. In the morning of 26 January, some brownish ash clouds mixed with the gas clouds from about 11:30. Around 14:45 I could see an even stronger ash emission there, which was nevertheless comparatively weak. The point of emission was apparently the upper northern summit area, which also generated some weak glow at times during the nights of the last weeks.
The volume of lava released since 27 November is calculated by INGV to be 3.7 - 4.8 million m3.
In the meantime, a sample of the current material, taken on 20 December 2022, was chemically analysed. It showed that the lava, with a CaO/Al2O3 ratio of 0.46 and an FeOtot/MgO ratio of 3.3, was more evolved than the lava emitted in 2022 during the paroxysmal phases of the Southeast Crater complex or during the May eruption. According to the INGV, this means that hardly any material was produced from greater depths [1].
The evaluation of the data from the GPS stations showed no significant changes for the period between 16 and 22 January [1].
The clinometric data showed no significant changes between 16 and 22 January [1].
The measurement of infrasound activity at the summit craters was massively disturbed by strong winds during the period 16 - 22 January and thus no data could be provided [1].
Sulphur dioxide emissions at the summit craters remained unchanged in the period between 16 and 22 January compared to the previous week and remained in the lower-medium range.
Soil carbon dioxide emissions (ETNAGAS station) held at medium levels between 16 and 22 January and were subject to a slight downward trend [1].
On the online seismograms of station ECNE, weak long-period signals as well as weak explosion signals were occasionally visible during the past week [2].
The tremor initially hovered on the border between low and medium levels last week, but then increased slightly and remained at lower-medium levels [2].
On 22.01., a quake of magnitude 1.6 was registered southeast of Monte Fontane (eastern flank). On 25.01., a quake of magnitude 1.7 occurred in the area of the summit craters [3].
My interpretation of the data and speculation about further development:
The analysis of the lava released in December showed that it was more evolved than the lava from the May 2022 eruption and significantly higher than the material emitted from New Southeast Crater during the paroxysmal phases in February 2022. This is also not surprising, because it was already largely degassed magma that generated practically no explosive activity, but flowed out very quietly. This magma had been stored in the mountain for some time and had time to evolve.
Unfortunately, there is no analysis (yet) of the lava currently being released. It is quite possible that it is somewhat more primitive than the December lava. However, as there is still no significant explosive activity, the proportion of more highly evolved and degassed magma still seems to be high. However, this could change in the near future and fresher magma could reach the surface.
Yesterday there were some ash emissions in the summit area of New Southeast Crater. It is possible that these were caused by deep-seated explosions, but smaller collapse events are more likely. However, if more fresh magma rises, the gases could cause strombolian explosions in the New Southeast Crater. Perhaps the ash emissions yesterday were already a first indication? Interesting is also the currently strongly fluctuating emission rate; a behaviour that has prevailed since mid-January and always causes new lava spurts. This could also be an indication that another, more gas-rich magma is now beginning to rise. But it could also mean that sufficient pressure can no longer build up to produce lava on a sustained basis. The temporary sinking and rising of the magma column under the New Southeast Crater could then also generate collapse events.
Thus, in my opinion, two developments are conceivable in the near future: 1. onset of strombolian explosions in the summit area of New Southeast Crater, with lava emission at the effusive vent remaining intensified in a push-like manner. 2. weakening or even end of the eruption and collapse events in the summit area or along the northern flank of New Southeast Crater associated with ash emissions.
In any case, Etna remains exciting!
1 - INGV-Sezione di Catania. 2023. Etna - BOLLETTINO SETTIMANALE - SETTIMANA DI RIFERIMENTO 16/01/2023 - 22/01/2023
2 - INGV-Sezione di Catania. 2023. Home. TREMORE VULCANICO. ECNE
3 - INGV. Osservatorio Etneo. Sorveglianza e Monitoraggio. DATABASE TERREMOTI. Localizzazioni di sala operativa. 2023.
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
Etna update, 20/01/2023
Last week, lava emission at the north-eastern base of Mt Etna's New Southeast Crater temporarily decreased. As a result, a new lava flow developed, which is now heading directly towards Valle del Bove.
On 14 January, the fronts of the lava tongues fed by the effusive vent at the northeastern base of New Southeast Crater stagnated at about 2200 - 2300 m altitude. During the evening, the associated thermal anomalies recorded by the Monte Cagliato thermal imaging camera weakened more and more. On 15 January, the lava flow was only active in the upper section, within the Valle del Leone. On 16 January, new small lava tongues were again working their way down the steep western slope of the Valle del Bove, but were no longer as well fed as in the previous weeks. On 17 January, only very small thermal anomalies were visible and it looked as if the lava emission had stopped completely. On the morning of 18 January, a new thermal anomaly appeared near the effusive vent. A new lava flow was now moving in an easterly direction, leaving the previously created lava field. By the evening of 19 January, the lava flow had continued on its easterly course, but progressed slowly despite the steepening terrain. This morning, its front stagnated at a roughly estimated altitude of about 2400 metres. Later, clouds moved in and hindered further observation.
Meanwhile, the summit craters continued their usual gas emissions during last week. They were strongest at Bocca Nuova and often pulsed. At New Southeast Crater, some gas was persistently emitted from the summit area. At Voragine and Bocca Nuova no gas emission was visible.
As INGV reports, the front of the most advanced lava flow was observed on 14 January at 2250 m elevation. By 14 January, a lava field with an area of 700,000 m2 had developed. The volume was calculated at 3.5 - 4.5 million m3 [1].
The analysis of the data from the GPS stations showed no significant changes for the period between 09 and 15 January [1].
The clinometric data did not show any significant changes in the Inclinations of the volcano between 09 and 15 January [1].
The measurement of infrasound activity at the summit craters was frequently disturbed by strong winds during the period 09 - 15 January. During the calm phases, activity similar to that of the previous week was recorded [1].
Sulphur dioxide emissions at the summit craters remained at the lower-medium level during the period 09-15 January.
Ground carbon dioxide emissions (station ETNAGAS) remained at a medium level between 09 and 15 January and were subject to only minor fluctuations.
The concentration of helium isotopes (3He/4He - ratio) in the Etna area, which was last determined on 09 January, was with a value of 0.63 similar to the last measurement in December. The value was thus still at a high level [1].
On the online seismograms of the ECNE station, weak explosion signals as well as individual long-period signals were regularly visible during the past week. From 18 January, there were also repeated phases of stronger noise that lasted only 1 - 3 minutes [2].
The tremor fluctuated between low and medium levels during the past week. The strongest decrease occurred on 17 January. Subsequently, the tremor increased again somewhat [2].
The source of the tremor was located between 09 and 15 January in the area below the central crater at an altitude between 1000 m and 2800 m [1].
My interpretation of the data and speculations about the further development:
The tremor was subject to some fluctuations in the last few days and the rate of lava production temporarily decreased significantly on 17 January. This could indicate that the supply of fresh magma to the effusive vent is gradually stalling. Presumably, not enough magma is rising at the moment or it has sought another path in the mountain along which it is migrating. Sulphur dioxide emissions from the summit craters have also been declining in recent weeks and there has been slight deflation of the volcanic edifice.
This suggests, in my opinion, that the current eruption may be slowly coming to an end. However, the still high Helium-3 concentration shows that fresh magma continues to rise under the mountain, which will be erupted sooner or later, at least in part. So it remains difficult to make a prognosis.
1 - INGV-Sezione di Catania. 2023. Etna - BOLLETTINO SETTIMANALE - SETTIMANA DI RIFERIMENTO 09/01/2023 - 15/01/2023
2 - INGV-Sezione di Catania. 2023. Home. TREMORE VULCANICO. ECNE
Etna update, 13/01/2023:
Last week, lava emission continued at the effusive vent at the northeast base of Mt Etna's New Southeast Crater. Different partial flows continued to be fed, moving through a system of tunnels and channels to the rim of the Valle del Bove. There, the fronts of two or three lava flows stagnated at about 2100 m above Monte Simone. From 08 January, the tongues retreated. Bad weather with fresh snow hampered observations until 10 January. From 11 January visibility was very good again and the hot, fan-shaped lava field stood out very well as a dark area on the snow-covered mountain. During the day, the fronts of the lava tongues descended again a little further down the slope and reached about 2200 m high terrain.
On 12 January, the southernmost lava tongue advanced even further down the slope, but then stagnated today at about 2100 - 2200 m high terrain.
Meanwhile, the usual gas emissions continued at the summit craters of Etna, which were still strongest at Bocca Nuova. During the nights, however, I could no longer observe any glow there. On the other hand, from 11 January onwards, some glow appeared on light sensible webcams in the upper northern summit area of New Southeast Crater. This was probably caused by rising heat or high-temperature fumaroles.
As reported by INGV, the front of the most advanced lava flow reached 2170 m high terrain between 04 and 07 January. The average production rate could be estimated at about 3 m3 lava/s with the help of satellite data. On 07 January, the volume of lava produced since the beginning of the eruption on 27.11.2022 was calculated to be about 2.5 - 4.3 million m3 [1].
The evaluation of the data from the GPS stations showed no significant changes between 02 and 08 January. However, the slight trend towards deflation of the volcanic edifice continued [1].
The clinometric data showed no significant changes in the slopes of the volcano between 02 and 08 January [1].
The infrasound activity at the summit craters was characterised by a relatively high frequency of events in the period from 02 - 08 January. However, the amplitude was low, indicating weak to moderate activity. The source of the events was Bocca Nuova [1].
The sulphur dioxide emissions at the summit craters decreased slightly in the period between 02 and 08 January compared to the previous week and were in the lower medium level.
Ground carbon dioxide emissions (station ETNAGAS) remained at a medium level between 02 and 08 January and were subject to only minor fluctuations [1].
The online seismograms of station ECNE showed occasional weak explosion signals or long-period signals during the past week.
The tremor was initially still on the border between low and medium levels last week, but then rose again somewhat from 10 January and has been slowly decreasing since then [2].
Until 05 January, the source of the tremor was located at an altitude of 2700 - 2900 m in the area between Southeast Crater and the effusive vent. From 05 January on a shift to the area northwest of Southeast Crater at an altitude of 2300 - 2700 m was detected [1].
On 07.01. a quake of magnitude 1.5 was recorded in the area of Grotta del Gelo (northern flank). On 12.01., two earthquakes with magnitudes of 2.3 and 1.9 were recorded near Biancavilla (southern flank) [3].
1 - INGV-Sezione di Catania. 2023. Etna - BOLLETTINO SETTIMANALE - SETTIMANA DI RIFERIMENTO 02/01/2023 - 08/01/2023
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 update, 06/01/2023:
During the past week, lava production continued at the northeast base of Mt Etna's New Southeast Crater. The lava continued to move in the form of several partial flows through the Valle del Leone to the edge of the Valle del Bove. On the steepening terrain, new tongues developed again and again. Sometimes a more southern and sometimes a more northern tongue was fed. As a result, the fronts of the tongues did not advance far and stagnated at about 2200 m high terrain in the area southwest to west of Monte Simone.
During 03 January, the intensity of the thermal anomalies visible from the active lava tongues in the Monte Cagliato thermal imager photos weakened considerably. By the evening, only the upper section of the lava field was active. In the afternoon of 04 January, the thermal anomalies in the area of the effusive vent intensified and some time later the lava tongues at the edge of the Valle del Bove became active again. Until the morning of 05 January, they again moved down the steep terrain, but initially did not advance further than about 2300 - 2200 m altitude.
By the evening of 05 January, the lava flow intensified and, especially in the southern section of the lava field, a lava tongue became more and more intense. In the early morning of 06 January, its front reached the valley floor of the Valle del Bove at about 2000 m altitude. At the same time, a little further north, another tongue made better progress than in previous weeks and moved towards the valley floor.
On the evening of 02 January, light sensitive webcams showed pulsating glow over Bocca Nuova. However, I could not observe any thermal anomalies. Probably deep-seated strombolian explosions started in one of the vents of Bocca Nuova. Also during the following nights, faint glow was visible above Bocca Nuova. On the evening of 05 January, the gas clouds above the summit crater were only sporadically illuminated, but in the early morning of 06 January, the glow became more frequent again.
The analysis of the data from the GPS stations showed no significant changes between 26 December and 01 January. However, a reversal of the trend towards inflation was observed during the past month and measurements between the Pizzi Deneri (EPDN), Cratere del Piano (ECPN) and Punta Lucia (EPLU) stations revealed a slight deflation of the volcanic edifice [1].
Clinometric data showed no significant changes between 26 December and 01 January [1].
Infrasound activity at the summit craters remained low during the period from 26 Dec to 01 Jan, but measurements were affected by wind. The source of the activity was Bocca Nuova [1].
Sulphur dioxide emissions at the summit craters hardly changed in the period between 26 December and 01 January compared to the previous week and remained at medium levels.
Ground carbon dioxide emissions (ETNAGAS station) remained at a medium level between 26 December and 01 January [1].
The online seismograms of station ECNE were initially still overlaid by noise caused by the persistently increased tremor. After the tremor decreased, weak explosion signals were occasionally visible from 05 January onwards [2].
In the past week, the tremor was initially still at a medium level and was subject to only minor fluctuations. From 05 January, it decreased significantly and reached a low level [2].
Between 26 December and 01 January, the source of the tremor was in the area of the Southeast Crater at an altitude between 2700 and 2900 m [1].
On 01.01., two earthquakes occurred in the area north of Ragalna (southern flank), reaching magnitudes of 2.0 and 2.8 [3].
My interpretation of the data and speculations about the further development:
It was interesting in the past few days that sporadic glow appeared again over Bocca Nuova after a long time. This was last the case in September last year. Presumably, deep-seated strombolian explosions are occurring there again now. It is also interesting that the tremor decreased significantly on 05 January, but this did not affect the lava production at the effusive vent. On the contrary, as the fronts of the lava eruptions have advanced today as never before during the current eruption, the production rate has apparently increased.
Since weak deflation has been measured at the volcanic edifice in recent weeks, more lava is probably currently being produced than is rising from under the mountain. If this continues, the end of the eruption could soon be in sight. However, there still seems to be plenty of fresh magma acummulating under the mountain, because the ratio of helium isotopes had reached high levels again in the last measurement in mid-December. Thus, it remains difficult to predict how the current eruption will continue.
1 - INGV-Sezione di Catania. 2023. Etna - BOLLETTINO SETTIMANALE - SETTIMANA DI RIFERIMENTO 26/12/2022 - 01/01/2023
2 -INGV-Sezione di Catania. 2023. Home. TREMORE VULCANICO. ECNE
3 - INGV. Osservatorio Etneo. Sorveglianza e Monitoraggio. DATABASE TERREMOTI. Localizzazioni di sala operativa. 2023.
A recent and impressive video of the effusive activity on Mt Etna from etna walk:
Etna update, 30/12/2022:
During the past week, effusive activity continued at the northeastern base of the New Southeast Crater. Several partial flows poured over the fan-shaped lava field in a northeasterly direction, crossed the Valle del Leone and reached the edge of the Valle del Bove. There they moved as several tongues in an easterly direction down the steep slope and formed an ever-widening lava field. The fronts of the tongues stagnated at 2100 - 2300 m altitude in the area southwest of Monte Simone.
Furthermore, I could not observe any explosive activity in the area of the effusive vents or in the summit area of New Southeast Crater.
At Bocca Nuova, pulsating gas emission continued. No significant gas emission was visible at Voragine and Northeast Crater.
As INGV reports, the front of the lava flow reached 2150 m high terrain on 25 December. Using MODIS/VIIRS satellite data, the volume of lava released so far could be estimated at 1,200,000 - 2,400,000 m3. The data also show that the production rate has increased from about 20 December, rising from about 1 m3/s initially to about 2 - 2.5 m3/s [1].
Analysis of the data from the GPS stations showed no significant changes between 19 and 25 December [1].
The clinometric data showed no significant changes between 19 and 25 December [1].
Infrasound activity at the summit craters was low during the period from 19 to 25 December. The source of the activity was Bocca Nuova [1].
Sulphur dioxide emissions at the summit craters decreased in the period between 19 and 25 December and reached medium levels.
Ground carbon dioxide emissions (ETNAGAS station) remained at a medium level between 19 and 25 December.
The concentration of helium isotopes (3He/4He - ratio) in the Etna area, which was last determined on 15 December, was higher than in the last measurements with a value of 0.64. High levels have now been reached again [1].
The online seismograms of station ECNE continued to be overlaid by noise caused by the persistently elevated tremor last week [2].
The tremor decreased somewhat on 24 December, but continued to hover at medium levels [2].
The source of the tremor between 19 and 25 December was in the area between Southeast Crater and Bocca Nuova at an altitude between 2500 and 2800 m [1].
On 23.12. a quake with a magnitude of 1.6 occurred in the area southeast of Case del Vescovo (southeast flank). On 23.12. a quake with a magnitude of 1.8 was measured on Monte Scorsone (east flank). On 25.12., a quake of magnitude 1.6 occurred southeast of Fiumefreddo di Sicilia (eastern flank) [3].
1 - INGV-Sezione di Catania. 2022. Etna - BOLLETTINO SETTIMANALE - SETTIMANA DI RIFERIMENTO 19/12/2022 - 25/12/2022
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
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.
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
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.
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.
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
