Observers noted that a fracture had formed on the SE flank of the central cone. In addition, an effusive vent in the saddle between the cone and the old cone of the Southeast Crater produced a small lava flow that traveled towards the Valle del Leone.
Activity decreased around and was over at about On 22 May a vent on the upper E flank of New Southeast Crater cone produced a series of ash emissions which rose several hundred meters above the summit and dispersed.
Some of the emissions had a thermal signature, indicating the presence of hot material. That evening Strombolian activity resumed at NEC; the rate and intensity of the activity fluctuated through the night. The strongest explosions ejected incandescent bombs up to a few hundred meters above the crater rim and onto the flanks. On 23 May sporadic ash emissions continued from the vent on the upper E flank of the New Southeast Crater cone.
Incandescent bombs were ejected above the crater rim and tephra was deposited on the flanks. During the morning of 18 May this activity was accompanied by ash emissions that drifted E and rapidly dispersed. Just after on 18 May cameras recorded the onset of activity at Voragine VOR crater, which within a few minutes evolved into a pulsating lava fountain. At the same time Strombolian activity at NEC diminished and dark ash emissions formed briefly.
Ash plumes from VOR rose as high as 3. During the afternoon lava overflowed from the W rim of the Voragine-Bocca Nuova depression, and traveled W within the summit area. The second lava flow remained active until the early morning hours of 19 May. Later that morning, the volcanic tremor amplitude sharply increased, and contemporaneously loud and virtually continuous bangs were heard in populated areas to the E and S of the volcano.
A dense eruption plume drifted E at an altitude slightly higher than 1 km above the summit of Etna. Ash and lapilli fell onto the E flank of the volcano, near an area affected by the tephra fall on the previous day.
A few hours later images revealed a new lava flow from VOR traveling W. Eruptive activity continued at least through , though the volcanic tremor amplitude had diminished.
At on 23 February an explosion at Northeast Crater NEC ejected incandescent tephra several tens of meters above the crater rim, and produced a dark ash plume that drifted NE.
A camera recorded lightning flashes in the plume. Weak ash emission rose from the crater during the rest of the morning. During December Strombolian activity was detected at NEC, with a few ejected incandescence bombs falling onto the outer flank and abundant ash emissions. Activity gradually diminished over a few days. The emissions ceased in the afternoon; very minor and sporadic explosions continued from the same vent during the following days.
Seismicity had significantly decreased. INGV reported that after a progressive intensification of activity during the evening of 2 December, an eruption at Etna's Voragine Crater peaked between and on 3 December.
During the peak period sustained lava fountains rose over 1 km above the crater with some jets of hot material rising 3 km high. Activity had almost ceased by dawn. This event was among the largest in the last 20 years, similar to large events occurring at the same crater on 22 July and 4 September At about on 4 December renewed activity at Voragine Crater was characterized by tall lava fountains and an ash plume that rose km high. The ash plume had a mushrooming top and produced deposits of coarse-grained pyroclastic material on the upper SW flank above 2 km elevation.
Ashfall was reported in Giarre-Zafferana Etnea on the E flank. The activity was accompanied by frequent ash emissions from a new pit crater that had recently opened on the upper E flank of the New Southeast Crater NSEC cone. Two more events occurred at Voragine Crater during December, between and on 4 December and and on 5 December, again producing tall lava fountains and many-kilometer-high ash plumes.
During the evening of 5 December activity at Voragine Crater progressively diminished. Between and on 6 December surveillance cameras recorded the onset of vigorous Strombolian activity from the vent on the E flank of the NSEC cone.
Repeated collapses of both old and new material from the cone's flank generated hot avalanches that traveled a few hundred meters E towards the Valle del Bove. Ongoing effusive activity through the day produced two lava flows; one advanced NE for less than 1 km and the other advanced E. Strombolian activity continued through the evening.
During the early morning hours of 8 December Strombolian activity progressively diminished and then ended. Later that afternoon weak Strombolian activity and ash emission were observed at the Northeast Crater.
At on 13 May a series of small collapses accompanied the opening of three vents, along a fracture oriented E-W, below the E rim of NSEC, one of which effused a small lava flow. At a fracture at the vent propagated m from the rim down the cone within 10 minutes. This event was accompanied by collapses, along with reddish ash ejection onto the summit area and the high S flank. Strombolian activity increased that night and was characterized by almost continuous Strombolian explosions, sometimes accompanied by ash emissions.
This activity continued during May. Ash plumes rose a few hundred meters and dispersed with the wind; minor ashfall was reported in areas from the S to the NE. A single lava flow traveled NE towards Mt. Rittman, and then E towards Mt.
Simone where it formed two branches. Activity decreased on 15 May and ceased on 16 May. This activity was preceded by a sudden increase in tremor amplitude and intense degassing during May; visible activity did not accompany the episode, and after a few days tremor returned to normal levels.
Resulting ash puffs rose a few hundred meters above the crater and dispersed. Poor meteorological conditions prevented views of the summit area during the first 36 hours of the eruption. During improved viewing conditions on the evening of 1 February, volcanologists observed Strombolian activity from a single vent in the saddle between the cones of the Southeast Crater SEC.
Explosions occurred every few seconds and ejected incandescent bombs m high. At the same time a vent at the base of the southern SEC cone issued a lava flow that traveled 2 km S, dividing into two branches. At dawn on 2 February the Strombolian activity produced a dense ash cloud that drifted E. At about emissions stopped and volcanic tremor suddenly decreased. The next day occasionally pulsating ash emissions rose from Northeast Crater and drifted SE.
Ash emissions continued through 17 January; cloud cover prevented observations of the summit area on 18 January. INGV reported that at night during January the frequency of Strombolian explosions at Etna's Voragine Crater decreased; however, some of the explosions ejected incandescent pyroclastic material outside of the crater and onto the W and SW flanks. On 7 January many of the small explosions generated brown ash plumes that rose a few hundred meters above Etna's summit and quickly dissipated.
Strombolian activity increased on 8 January, possibly from two vents within the crater. Pyroclastic material continued to be ejected out of the crater. Early on 9 January Strombolian activity again decreased and gave way to ash emissions that rose several hundred meters. Ash emissions continued the next morning, decreased, and had almost completely ceased by late morning. Ash emissions resumed in the afternoon and were sometimes accompanied by Strombolian explosions.
Ash emissions on 13 January were continuous in the morning but then decreased in frequency by the afternoon. During the night on 1 and 2 January cameras recorded intermittent flashes from Voragine Crater one of four summit craters , indicating Strombolian activity there for the first time in nearly two years.
On the evening of 3 January explosions ejected incandescent material m above the crater rim. Inclement weather prevented observations of the summit area so the erupting crater was not identifiable. Tremor began to decrease at , and indicated that the eruption was over at During some nights small Strombolian explosions ejected incandescent material a few tens of meters above the crater rim. Lava continued to flow about 3 km NE towards Monte Simone. On 9 August INGV reported that volcanic tremor decreased and an ash plume rose to 1 km above the July 25 area of Etna and returned to strong Strombolian activity in the evening.
Strombolian activity increased at New Southeast Crater that was accompanied by small emissions of black ash that remained within the crater. The vent was located around 3,, m elevation. Weak and sporadic strombolian explosions and small ash emissions were observed during July from New SE Crater, but by 11 July this activity had ceased.
Activity from the new fissure continued through 11 July with frequent strombolian explosions that were audible in nearby towns. Some explosions ejected incandescent pyroclastic material a few tens of meters above the crater rim that occasionally fell onto the outer flanks.
On 14 June a new eruptive episode began within the NSEC, beginning with near-continuous Strombolian explosions and lava fountaining. Fine ash emissions were concurrent with lava that began to overflow the edge of the SE crater, forming a flow that continued downhill on the W wall of Valle del Bove. During the morning of 15 June the overflowing lava followed the fissure that had been formed on 28 November A spatter cone also formed in the E sector of the cone. During June volcanic tremor increased sharply and remained at a medium-high level until 18 June when it returned to normal levels.
INGV noted that this activity was similar to the episode of effusive lava emissions observed during and December in terms of duration and intensity. Some explosions ejected incandescent pyroclastic material a few tens of meters above the crater rim that rarely fell onto the outer flanks. Some explosions ejected incandescent pyroclastic material out of the crater and onto the upper S and SE flanks of the cone. A few small collapses occurred on the cone's unstable E flank. The frequency and intensity of Strombolian explosions slightly increased late in the evening on 30 April.
Degassing at the Northeast Crater also increased and thermal anomalies were detected by a camera. Weak Strombolian activity continued to be detected through 1 May. Strombolian activity gradually intensified during the evening of 2 April and then decreased the next morning. Some collapses from the E flank of the cone were also observed that morning.
Poor weather conditions prevented views of Etna for a few days, but by 7 April the lava flows had ceased and Strombolian activity had sharply declined. No activity was observed on 8 April. Lava emissions from the lower side of the NSEC significantly decreased; on the evening of 28 March a small lava flow continued to advance but had stopped and was cooling the next day.
Strombolian activity intensified during March, producing more ash, and then decreased; no ash was emitted on 23 March. Lava flows originating from a vent on the upper wall traveled towards the upper part of the W wall of the Valle del Bove and also NE in the direction of Monte Simone. Lava flows originating from a vent on the upper wall traveled towards the upper part of the W wall of the Valle del Bove. After several days of lava emissions from a vent on the lower part of the NSEC cone, during March lava flows originated only from a higher vent and traveled 1.
On 8 March sporadic emissions of hot material with small amounts of volcanic ash originated from Bocca Nuova. An unstable part of the lower E flank of the cone that collapsed on 11 February continued to produce small collapses with reddish ash clouds. Lava continued to flow from a vent on the lower part of the NSEC cone to the W wall of the Valle del Bove, and during March the flows reached the base of the wall.
An unstable part of the lower E flank of the cone that collapsed on 11 February continued to produce small collapses with reddish ash clouds, and thermal anomalies. An unstable part of the lower E flank of the cone that collapsed on 11 February continued to produce small collapses and reddish ash clouds.
Lava continued to flow from the cone towards the Valle del Bove, and by nightfall had reached the base of the steep W wall of the valley, then advanced on the flat land to the N of Mount Centenarians. Strombolian activity continued during February.
Lava emissions declined, but produced lava flows a few hundred meters long. At on 15 February an explosion generated a vapor-and-ash plume, and was then followed by more explosions from the same area. The flow traveled m towards the W wall of the Valle del Bove, and remained active the next day. During February Strombolian activity continued to produce small quantities of ash. Lava continued to flow from the vent at the base of the cone.
The lava flows reached the base of the W slope of the Valle del Bove. On 6 February ash emissions ceased and small Strombolian explosions ejected incandescent pyroclastic material m above the crater. On 7 February Strombolian explosions ejected material onto the flanks of the cone, and the next day ash puffs were observed. During February activity continued to be characterized by Strombolian activity, periodic ash emissions, and advancing lava flows.
At on 11 February a large quantity of reddish brown ash emitted from an area near the vents formed a very dense hot flow which quickly reached the base of the W wall of the Valle del Bove.
Reddish brown ash emissions continued after the event. Weak and sporadic Strombolian explosions were detected at night, but then the thermal cameras recorded no anomalies associated with Strombolian activity. Lava flows from two vents at the base of the NSEC cone continued to effuse at a very low rate. Weather conditions almost entirely prevented observations of Etna from the morning of 30 January until the evening of 3 February. Late on 3 February observers noted that the lava flow remained active and was several hundred meters long.
Almost continuous ash emissions from NSEC began at about on 4 February and continued into the night; about ash puffs were separated by steam emissions. Ash plumes drifted E. After sunset jets of hot material were observed rising m above the crater rim. At the ash emissions and injection of incandescent material ceased, but the lava flow continued and reached 1 km long. Strong degassing continued at least through 22 January.
Some explosions generated very small ash emissions that barely rose above the crater rim. Late on 22 January a small lava flow from the vent on the high E flank of the NSEC cone traveled a few hundred meters in a few hours. Strombolian explosions ejected incandescent pyroclastic material onto the cone flanks. The frequency and intensity of the explosions decreased early on 23 January, and the lava flow stopped advancing.
Weak Strombolian activity and the advancing lava flow continued during January, although on 25 January the amount of ash produced by the Strombolian activity increased. On 26 January an ash plume drifted E. By evening the intensity of the Strombolian activity as well as the amount of ash in the emissions decreased. The lava flow was 4 km long. Volcanic tremor amplitude remained at low levels.
On 3 January staff doing field work noted that the effusive activity had stopped. During the early morning hours on 29 December a camera recorded weak and sporadic incandescence from NSEC. Strong pulsating degassing also occurred at Northeast Crater. After the explosion mild Strombolian activity continued and then progressively intensified in the evening.
Frequent powerful explosions from two vents located within the crater were audible in a vast sector around the volcano. Diffuse ash plumes drifted NE. Contemporaneously, two lava flows are active, one from a vent on the E flank of the NSEC cone, and the second, fed directly from the crater, traveled down the NE flank of the cone.
Intermittent ash emission gradually turned into Strombolian activity. After the activity intensified; small ash puffs were produced and Strombolian explosions ejected incandescent pyroclastics onto the flanks of the cone. Over the next few hours activity continued to intensify and a diffuse ash plume drifted ESE.
At lava overflowed the SE crater rim and flowed towards the Valle del Bove. During the night explosive activity continued to intensify, and by on 15 December Strombolian activity was intense and virtually continuous. After explosive activity started to diminish, and at the volcanic tremor amplitude and the intensity and frequency of Strombolian explosions showed a sharp drop.
Explosive activity continued to produce copious amounts of ash until about According to a news article, the ash emissions caused the cancellation of more than 20 flights in and out of the Catania airport.
At and two vents opened within the deep trench cutting the SE flank of the NSEC cone where lava was still flowing from the crater since the previous evening , the first just a few tens of meters below the crater rim, the second about m further downslope. Both vents initially produced lava fountains for a few minutes, with jets a few tens of meters high, and then produced lava flows that descended through the trench. Between on 15 December and the morning of 16 December ash emission varied in frequency and intensity, related to variations in the intensity of the Strombolian activity at NSEC.
During the afternoon and evening of 15 December explosive activity lasted a few to a few tens of minutes and Strombolian activity became significantly more intense or passed into pulsating, low lava fountains.
The more intense periods produced greater amounts of ash leading to ashfall in populated areas on the E and SE flank, from the Milo-Zafferana area toward the Ionian coast. At night during December lava flows continued to flow towards the Valle del Bove. On 15 December small and periodic ash emissions also occurred from Northeast Crater. Small thermal anomalies detected with a thermal camera were detected during December.
Strombolian activity at the NSEC continued through 16 December at a slowly decreasing rate and with numerous minor intensifications that generated diluted ash plumes. Lava effusion also gradually diminished, but at about on 16 December, a short fissure opened on the lower NE flank of the NSEC cone, producing a small lava flow which advanced a few hundred meters. Explosive activity finally ceased around midnight on 17 December.
Very slow lava effusion continued, at a gradually decreasing rate, from the fissure on the NE flank of the NSEC cone, through the night of December. Weather clouds prevented observations of the event.
Vigorous Strombolian activity on 2 December produced a plume comprised mostly of gas drifting N. The activity intensified during the evening and evolved into a paroxysmal event that finished by The event was characterized by tall lava fountains, lava flows, and a plume laden with pyroclastic material that drifted NNW and deposited ash and lapilli in that area.
The next day sporadic explosions continued, inclement weather however prevented visual observations. The episode was characterized by a rapid evolution from Strombolian activity to lava fountains, an ash plume that rose several kilometers and drifted NE, and lava flows that were significantly less extensive than those emitted during the November paroxysm.
INGV-Osservatorio Etneo staff visited the area the next day and noted that explosions were heard one to three times per minute, and during times of good visibility no pyroclastic material was ejected. Sporadic ejections of incandescent pyroclastics were observed after nightfall. Early on 16 November Strombolian activity gradually intensified; however, only pulsating puffs of vapor, but no ash, were produced. On 17 November a new paroxysmal eruptive episode was characterized by violent Strombolian activity and pulsating lava fountains, emission of lava flows that traveled S, ESE, and NE, and the formation of an eruption column charged with pyroclastic material that drifted NE.
The episode ended with a long series of powerful explosions and loud bangs heard tens of kilometers away. Strombolian activity continued until the late evening; after nightfall, a small lava flow issued from an effusive vent located on the lower E flank of the NSEC cone. During November several phases of frequent explosions produced ash puffs visible during the daytime and ejected incandescent material from Strombolian activity was visible at night.
On 8 November the explosions occurred at intervals of several hours, producing small ash plumes that rose a few hundred meters above the summit and drifted ENE. A culminating phase of lava fountains, ash emissions, and lava flows began at on 11 November, after about 10 hours of gradually intensifying Strombolian activity.
Weather conditions prevented visual observations, but a strong increase in the volcanic tremor amplitude was detected. The phase of maximum intensity lasted about 7. Ash and lapilli fell in areas E and NE. Vigorous Strombolian activity continued, with explosions at intervals of minutes, which launched incandescent material as high as m above the crater rim. At night during November Strombolian activity ceased and the lava flows were no longer active. A brief glow seen on surveillance cameras was followed by ash emissions.
The event was accompanied by a strong seismic signal detected by summit seismic stations. Poor weather prevented additional observations. A gas plume laden with pyroclastic material rose several kilometers above the summit and drifted SW, affecting population centers as far as the Caltanissetta area. According to a news article a representative from Catania airport noted that the eruption caused the closure of nearby airspace before dawn through the early morning.
Lava emitted from the saddle between the two cones of the Southeast Crater advanced S, destroying two wooden shacks at Torre del Filosofo. Another smaller lava flow descended the SE flank of the NSEC cone, partially filling the deep collapse scar formed during the 27 April paroxysm. At vigorous ash emissions from the Northeast Crater formed a dark brown plume that rose 1 km; ash emissions from that crater continued through late evening.
Lava fountaining from NSEC continued through the late morning and was then followed by a long series of powerful explosions audible to many tens of kilometers away. Strombolian explosions occurred in the late evening. Lava flows continued to advance the next day. Sezione di Catania - Osservatorio Etneo reported that a series of small and sporadic ash emissions from Etna's New Southeast Crater NSEC began during the morning of 3 September, marking the end of four months of complete quiescence.
At daybreak small ash puffs were emitted once or twice per hour. The same morning intense incandescence emanated from Bocca Nuova. The report stated that since early May only degassing from the summit craters was noted, along with usual bangs and rumblings from deep within the conduit of the Northeast Crater NEC , which during the past few weeks had become more continuous and louder.
Activity increased on 21 April and was characterized by Strombolian explosions and frequent ash emissions. Eruptive activity and the volcanic tremor amplitude gradually increased in the evening of 26 April.
Activity increased on 16 April with ejected incandescent tephra and small ash puffs from a vent inside NSEC, followed by weak Strombolian explosions. Strombolian explosions became more frequent and intense on the morning of 18 April and then were almost continuous by During the next two hours lava fountains developed and a dense plume drifted SSW.
Ash and lapilli fell in between the villages of Ragalna, Belper, and Paterno, as well as the tourist area "Etna Sud. Three lava flows were produced; the largest flowed through the deep notch in the SE rim of the crater and traveled 4 km towards the Valle del Bove. The interaction of the lava with snow led to rapid melting, generating small lahars.
The two other lava flows originated in the saddle between the two SEC cones; one traveled N and the other S. After the lava fountains ceased, strong explosions were heard the rest of the day. On 19 April explosions produced little puffs of ash and ejected hot tephra.
The twelfth episode occurred two days later during the late afternoon of 20 April. Intermittent explosions ejected incandescent tephra and generated small ash puffs on 19 April. During the evening a large dark plume rose from NSEC, and sporadic Strombolian explosions were observed.
The explosive activity ceased in the late evening, but shortly afterwards the lower of the two effusive vents at the base of the NSEC cone produced a lava flow that traveled 1. Around ash puffs rose from the crater, followed by incandescent tephra ejected at Within a few minutes sustained lava fountains were observed, along with a tall eruption plume that drifted E. On 20 April several lava flows on the W wall of the Valle del Bove interacted with the snow, generating explosions and lahars.
Around lava-fountain activity decreased and turned into explosions and ash emissions. At the paroxysm was over. In the evening, the lava flow emitted from the effusive vent at the base of the SE part of the NSEC cone was still well-fed. Poor weather conditions prevented visual observations until the evening of 21 April, when surveillance videos showed sporadic Strombolian explosions accompanied by small ash puffs at the NSEC, and the emission of a small lava flow from the base of the cone.
Sezione di Catania - Osservatorio Etneo reported that the tenth eruptive episode of began at Etna's New Southeast Crater NSEC on 8 April with sporadic ash emissions occasionally accompanied by incandescent material. A large explosion at was heard up to 15 km away. The ash emissions continued for about 48 hours. In the late afternoon on 10 April Strombolian activity began, producing minor ash emissions during some of the explosions.
In the morning on 11 April Strombolian explosions occurred about every seconds, ejecting incandescent pyroclastics several tens of meters above the crater rim. Strombolian activity increased slowly in intensity and frequency of explosions throughout the day; contemporaneously the volcanic tremor amplitude continued to show a gradual rise.
Late in the afternoon frequent and very powerful Strombolian explosions occurred every seconds and were widely audible around the volcano. Jets of incandescent pyroclastics often rose m above the crater rim and generally contained minor amounts of ash. Around , a small amount of lava flowed over the deep breach in the SE rim of the crater. In the late evening it stopped and showed evidence of cooling. Throughout the night powerful explosions alternated with intermittent, low lava fountains.
At daybreak on 12 April a dense eruption plume containing relatively minor amounts of pyroclastic material drifted ESE. At a flow of hot pyroclastic material from the same area traveled about 2 km NE in less than 1 minute. In the meantime, eruptive activity continued at the NSEC with frequent, powerful Strombolian explosions and emission of modest quantities of volcanic ash, which was rapidly dispersed.
Shortly before , the eruptive activity changed from low lava fountains to Strombolian explosions and intermittent ash emissions. Vigorous ash emissions resumed at both from the main vent of the NSEC and from the saddle vent. Expulsion of blocks, bombs and ash from the saddle vent continued until , when the main vent of the NSEC reactivated, and for the next nearly 20 minutes both vents were the source intense ash emissions.
The activity shifted back entirely to NSEC, entering into the true paroxysmal phase of this episode at with sustained lava fountaining, accompanied by a return to high levels of the volcanic tremor amplitude. During the following 10 minutes, there was a considerable increase in the quantity of pyroclastic material in the plume, which drifted ESE. Maria la Scala, although the quantity of fallout was much smaller compared to those of the previous paroxysms.
Sustained lava fountaining continued for about one hour; a few minutes after the activity switched to sporadic Strombolian explosions and ash emissions, which gradually diminished in vigor.
During and , repeated collapses occurred on the SE flank of the NSEC cone, possibly from new vents at the base of the cone, from which a new lava flow traveled toward the Valle del Bove. The collapses generated avalanches and clouds ash. Explosive activity progressively diminished and completely ceased around On the evening of 12 April, the lava flows emitted from the saddle and from the various vents on the flanks of the cone were incandescent and slowly moving; during the night, the surveillance cameras showed the cessation of all lava emission and the cooling of the flows.
However, on the morning of 13 April, slow lava effusion resumed from the lower of the vents and a small flow advanced a few hundred meters. This flow ceased in the early morning hours the following day. Once more, on the evening of 14 April, there was a rather weak resumption of effusive activity from this vent, which ceased after a few hours.
Cloud cover prevented further visual observations through the following night; however, sporadic glow suggested Strombolian activity. On the morning of 3 April, the volcanic tremor amplitude slowly increased and was accompanied by numerous explosion signals. Field observations revealed that at vigorous Strombolian activity was occurring at one or two NSEC vents, with jets of pyroclastic material rising up to a few tens of meters above the crater rim.
The activity progressively intensified between and , with frequent, powerful Strombolian explosions often generating loud bangs and launching great quantities of incandescent bombs with diameters of many meters onto the flanks of the cone. Shortly after , ash emission started from the saddle vent SV , followed a few minutes later by Strombolian explosions from the same vent.
At , a continuous jet of incandescent lava fountained up to m, whereas the vents within NSEC continued to produce powerful loud explosions.
During the same time interval, lava emissions started from SV, feeding a flow that went S. Since the eruptive plume drifted SE and contained modest amounts of volcanic ash. At around ash emissions progressively increased and the volcanic tremor amplitude showed a rapid rise. Between and low lava fountaining continued from SV, whereas the vents within NSEC emitted intermittent, pulsating lava fountains.
The incandescent jets from the vents within NSEC rose up to m above the crater rim. At , lava fountaining at SV intensified, with jets rising m high. Explosions from the vents within NSEC continued, producing loud detonations every seconds. Lava fountaining significantly decreased between and when a new eruptive vent NV opened a few tens of meters to the W of SV, on the E slope of the old SEC cone, and emitted grayish-brown ash. Fallout of pyroclastic material affected almost the same area that had already been subjected to the heavy shower of lapilli on 16 March: Zafferana Etnea and Santa Venerina on the SE flank, and the N part of Acireale plus a number of smaller villages to the N at the S margin of Giarre, in the Ionian area.
The deposit was thinner than that of 16 March, and the dimensions of the lapilli were notably smaller. Between and , the eruptive activity reached a new peak of intensity with sustained lava fountains from SV and powerful explosions from the vents within the NSEC.
Two lava flows emerged from the same area and traveled toward the Valle del Bove. Sometime during the afternoon of 15 March, numerous explosion signals were detected, and the volcanic tremor amplitude increased through the evening. After nightfall, incandescence from the NSEC was visible, and nearby residents on the SE flank heard loud bangs coming from the crater. This activity continued during the night and through the following morning.
At daybreak on 16 March, numerous gas rings formed by the more powerful explosions were recorded by the monitoring cameras and photographed by observers in the field. During the early afternoon of 16 March, activity started to intensify more rapidly, and frequent jets of incandescent lava were launched up to m above the crater rim.
Approximately 15 minutes later, explosions became progressively more energetic, ejecting incandescent bombs onto the outer flanks of the cone; contemporaneously, the quantity of pyroclastic material ash and lapilli in the eruptive plume increased. Ash plumes drifted SE. Between and , the eruptive activity changed from Strombolian explosions to lava fountaining, with the highest jets rising m above the crater rim.
The eruption column rose about 2 km above the summit of Etna before it was blown SE by the strong winds. Around , several lightning flashes within the eruptive cloud were observed. Observations made after the end of the paroxysm revealed that a lava flow was emitted from the area of the saddle between the SEC cones.
During the phase of most intense lava fountaining, numerous volcanic bombs fell onto the pyroclastic cones formed during the eruption, up to 2 km from the NSEC. Heavy tephra fall, mostly in the form of scoriaceous lapilli, affected the SE flank; on the W headwall of the Valle del Bove this material was still incandescent.
Further downslope, in the towns of Zafferana Etnea, Santa Venerina, and a number of villages to the N of Acireale, the tephra fallout formed a continuous deposit of scoriaceous lapilli, which in the N portion of Zafferana Etnea locally was up to 10 cm thick. Many clasts in this area had diameters from 5 to 8 cm, and more rarely up to 10 cm.
Numerous car windshields, skylights, and roof tiles were broken. Even on the Ionian coast, the deposit consisted largely of lapilli, with only a minor fraction of ash. The activity started to decrease around , and at the activity evolved into violent explosions that ejected broad fans of large, incandescent bombs, accompanied by loud bangs and detonations.
These explosions ceased at , but at two particularly powerful explosions ejected large incandescent rock fragments towards the SW at least 1. A few weaker Strombolian explosions occurred shortly after At on 17 March, a series of explosions started at Voragine, which continued for about 5 minutes, generating strong thermal anomalies that were recorded by the thermal surveillance camera, and probably produced small ash puffs.
During the next few hours, weak glow coming from Voragine was recorded by a monitoring camera. There were also small collapses and slides of still hot material from unstable portions on the NSEC cone, which generated minor quantities of ash.
On 5 March an explosion from the vent in the W part of NSEC was detected at and ejected incandescent bombs several tens of meters above the crater rim. This explosion was followed by similar ones, initially separated by intervals of minutes, but then gradually became more frequent. As the evening went on, the activity at NSEC progressively intensified; likewise, the volcanic tremor amplitude started to rise.
Around on 6 March, lava started to flow from the saddle between the two SEC cones; a few minutes later, an eruptive fissure with several vents opened in the lower portion of the saddle. Lava jets became continuous around , forming a fountain that rose m above the crater rim.
Various vents were active within the NSEC, in the saddle area, and at the base of the saddle, from where a voluminous lava flow expanded S and SE. Around this lava flow had reached the area of Belvedere station. For the next 30 minutes, lava fountaining continued with jets rising to m above the crater.
They also found that the volcano began emitting more carbon dioxide approximately six months before the eruption and that there were fluctuations in many other gasses as well. They suggest that together the changes in degassing ratios could be an indication of magma pressure buildup leading to an eruption. They conclude their paper by suggesting that the eruption in was inevitable, because the volcano was extremely over-pressurized in the weeks before it blew.
Explore further. More from Earth Sciences. Use this form if you have come across a typo, inaccuracy or would like to send an edit request for the content on this page. For general inquiries, please use our contact form. For general feedback, use the public comments section below please adhere to guidelines. Your feedback is important to us. However, we do not guarantee individual replies due to the high volume of messages. Your email address is used only to let the recipient know who sent the email.
Neither your address nor the recipient's address will be used for any other purpose. The information you enter will appear in your e-mail message and is not retained by Phys.
You can unsubscribe at any time and we'll never share your details to third parties. More information Privacy policy. This site uses cookies to assist with navigation, analyse your use of our services, collect data for ads personalisation and provide content from third parties. By using our site, you acknowledge that you have read and understand our Privacy Policy and Terms of Use. Credit: CC0 Public Domain. More information: Intense overpressurization at basaltic open-conduit volcanoes as inferred by geochemical signals: The case of the Mt.
Etna December eruption, Science Advances Citation : Degassing data suggests Mt. This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission.
The content is provided for information purposes only. Safety is far from the only reason to use a guide, of course. To avoid winter conditions, autumn or spring are best.
Sicilian summers are very hot, but treks do still happen. Just be prepared for an early start to beat the heat. I was excited at the start of our trek as it was a really bright and clear day. Though, luckily, that is most days in Sicily. Clouds descended about an hour into our trek but we could still see a lot and enjoy the views. Sicily may be known for its beaches, historic old towns and endless food, but there are plenty of hiking opportunities here too and this is one of the most spectacular.
As a way to get below the surface of Sicilian people and the magnificent natural wonder many live next to, Mt Etna is perfect. But for my first volcano adventure, this adventure was perfect. It was definitely a physical challenge but at least I burnt off some of the granite and cannoli.
This content is not available in your region. The group trekking up Mount Etna Trails of Sicily. Woman watches a crater on Mt Etna smoking Trails of Sicily. Hikers taking in the view of one of Mt Etna's craters Ruth Wright. Mount Etna Trails of Sicily.
Women Beyond Borders.
0コメント