Etna, Sicily, Italy

 

September 15, 1998

An explosive eruption occurred at SE Crater after about six weeks of inactivity. Several powerful explosions occurred on the morning of September 15. At one point, bombs were ejected 1000-1300 ft (300-400 m) above the crater rim. Pyroclastic jets occurred every 2-5 seconds and rose several hundred meters above the summit of the volcano. Some sources reported a fracturing of the crater, causing volcanic emissions down the slope. The large intracrater cone that had been growing since 1996 was virtually destroyed by this event. This explosive event caused ash falls in inhabited areas on the eastern side of the volcano. No damage has been reported.

 

August 24, 1998

Vigorous activity is continuing at Etna following the paroxysmal eruption of July 22. Powerful Strombolian activity caused light ash falls on the southeastern side of Etna on August 18. Some of this ash fell as far away as the outskirts of Catania. Bomb ejections accompanied these ash emissions. Spectacular pyroclastic activity was seen from the east flank of the volcano on the night of the 18th. Bombs were ejected up to 1300 ft (400 m) into the air during this activity and fell down to the eastern base of the main summit cone. Loud explosions were heard from as far away as Catania.

 

July 22, 1998

Two earthquakes shook Mt. Etna on July 22, causing increased activity at the volcano. Following these quakes, lava began to flow down Etna's slopes, and steam and ash rose six miles (~9.5 km) into the air. About a quarter of an inch of ash from this event fell on Catania's airport, forcing its closure late Wednesday. Some scientists believe this activity is a precursor to a larger future eruption of Etna.

 

July 1, 1998

Vigorous lava fountaining occurred at Voragine on the morning of July 1. This activity lasted between 30 minutes and one hour. Many bombs up to 5 ft (1.5 m) in diameter fell on the eastern side of Etna's main summit cone. The activity could be seen for several miles. Lava fountaining and ash emissions have alternated frequently between the vents of Voragine within the last week.

Currently, ash-rich explosions are occurring from the northern vent in Bocca Nuova, and lava is slowly flowing from SE Crater. Some explosions from this crater produce small ash plumes. Lava effusion from the intracrater cone in SE Crater is continuous. Explosions from the northern vents of Bocca Nuova are infrequent but very powerful. Large quantities of ash were ejected during at least one of these explosions.

 

June 11, 1998

Extremely intense explosive activity is currently occurring at Bocca Nuova and Voragine craters. This morning, strong explosive activity from Voragine could be heard over 6 miles (10 km) from the summit. Lava fountains were seen jetting hundreds of meters above the erupting vent in the SW part of the crater. Bombs up to ~3 ft (1 m) in diameter were thrown into the air with these jets. Powerful explosions caused ground shaking at the summit cone of Etna and ejected bombs across a wide area far beyond the southern rim of Voragine. Explosions were occurring 1-2 times per second, with large explosions every 1-2 minutes.

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At the NW eruptive area of Bocca Nuova, three vents are very active. Explosive activity is far more vigorous at these vents than it was a week ago. When observed this morning, the western vent would occassionally produce a plume of dense ash with huge bombs showering down in the area of the vent. The eastern vent would then produce low fountains with many large bombs directed to the south. The eastern vent later exploded violently, showering many bombs far beyond the western crater rim. At 10:58 AM (local time at Etna), a powerful explosion from the eastern vent ejected huge bombs in all directions. Many bombs up to 5 ft (1.5 m) long were thrown over half way down the summit cone.

It is currently not safe to approach either Voragine or Bocca Nuova. Bombs are being ejected frequently with little or no warning at low angles. This puts anyone who nears the main summit cone in great danger.

 

June 5, 1998

Spectacular activity was viewed at three of the four summit craters on Etna on June 4-5. While NE Crater was quiet, Bocca Nuova, SE Crater and Voragine were more active than they had been in several months. Explosive activity was varying between three vents on the central intracrater cone of SE crater, which has grown significantly during the past two weeks. Bombs were ejected from the northernmost of these vents, but did not leave the crater. Lava flowed from a vent on the eastern intracrater cone and flowed over the northeastern flank down to the base of the cone.

Close up view of the effusive vent taken on June 4, 1998

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Eruptive activity continues at the northwest and southeast areas of the Bocca Nuova crater floor. Bombs were occasionally ejected above the southern rim of Bocca Nuova from a collapsed pit in the southeastern area of the floor. At least five vents produced spectacular explosions and lava fountains at the northwestern eruptive area. Several flows from this area moved west and southwest over the crater floor.

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June 4 eruption of the southwestern vent of Voragine.

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The most impressive activity took place in the southwestern part of the Voragine crater floor. The vent in this area has enlarged significantly since April 6, and a low pyroclastic cone grew around the vent. On June 3, extremely loud explosions were heard many kilometers away. Huge magma bubbles were seen bursting within the vent leading up to intense periods of fire-fountaining. Many of the lava jets reached heights of 500 ft (150 m) above the summit of the 1964 cone. The southwestern and western rims of the Voragine crater were heavily showered with bombs, making approach from those directions extremely dangerous.

The current activity has lasted about a week thus far. The activity at the Voragine crater is the strongest there since it became active in July 1997. It is also some of the most vigorous eruptive activity at Etna's summit since activity started there nearly three years ago. The lava flows on the Bocca Nuova crater floor indicate that the top of the magma column is rising again. The current eruption rate of all three craters combined is about 3-5 cubic meters per second. This is significantly higher than the average output of Etna during the periods of "persistent summit activity".

 

June 1, 1998

Activity at Etna's summit craters has increased over the weekend. Eruptions have once again started at Bocca Nuova after a several month period of little activity there. There was also a series of ash emissions from NE Crater on June 1. This is the first time NE Crater has been active since March 27. Activity continues at several other craters in the form of lava flows and explosions. These explosions are currently occurring every 1-2 seconds. This type of activity on Etna's summit has remained almost constant. It is known as Etna's "persistent summit activity." It occurs at the rate that magma is supplied into the volcano, which is estimated to be about one cubic meter per second.

 

March 31, 1998

NE Crater of Etna produced a spectacular lava fountain during the night of March 27-28. This event lasted about two hours. The fountain reached heights of ~1000-1200 ft (~300-350 m) above the rim of the vent. Pyrocalstic material fell in and around the crater during the event. Volcanic bombs were thrown hundreds of meters above the crater prior to and during the fountaining. Some of these bombs were thrown as far as 1 km to the south of the vent. SE crater was also extremely active at this time, with Strombolian activity and a lava flow down the southwestern flank of the SE Crater cone.

 

January 16, 1998

Explosive activity continues at SE Crater of Etna. Lava is flowing down the southwestern side of the main SE Crater cone. Strombolian activity is also occurring from the intracrater cone. Most of this activity shows no change from the past several weeks or even months. Even though this summit activity continues, reports of its magnitude and danger have been greatly exagerated.

January 11, 1998

Continued collapse of the Bocca Nuova crater walls led to strong ash emissions from the crater. A magma column may have intruded into a fracture in the western side of the crater. This could eventually lead to a flank eruption. Although a flank eruption is possible, the volcano continues its normal pattern of summit activity. Ash emissions from Bocca Nuova remain fairly constant. Strong ash emissions are also coming from NE Crater. SE Crater continues activity with Strombolian bursts and lava flows on the southern flanks of the cone.

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Eruptive activity at the intracrater cone on August 5, 1997. Lights of the urban center on the Eastern flank of Etna can be seen to the right

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July 19-20, 1997

A small amount of lava overflowed from SE Crater at Etna on the night of July 19-20. This is the first time lava has flowed from that crater since 1990.

 

July 11, 1997

Intense Strombolian activity at SE Crater on July 11, 1997

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Strombolian activity continues from three vents on Etna. Lava is also being emitted from Bocca Nuova and a small cone in Southeast Crater. Explosions at this cone happen about every 30 minutes and last for about 15 minutes. There is a lava flow about 650 ft (200 m) long within Southeast Crater. At the current rate, it could take several weeks for the crater to overflow.

 

July 8, 1997

Activity at Etna is increasing rapidly. Strombolian explosions can be seen at night from 20 miles (30 km) away. Southeast Crater of Etna is rapidly filling with lava from a new cone and could overflow in the coming days. Strombolian activity and lava flows are also occurring in Bocca Nuova, the farthest west crater on Etna's summit.

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Three strong episodes of lava fountaining occurred at the North-East Crater of Mt. Etna during the last week. On November 9, 1995, a episode lasted one hour, producing abundant ash and lapilli that fell on a wide area of the southeast flank of the volcano, down to the town of Catania. Catania, with a population of one million people, is about 20 miles (30 km) southeast of the summit of Etna. The second episode, on November 10, 1995, produced scoria fallout only on the upper flank of the volcano, near the vent. The third episode, on November 14, 1995, lasted about one hour and produced fallout of ash and lapilli on a narrow zone of the northeast flank of the volcano. Last month, explosions tossed bombs onto the rim of Northeast Crater. The bombs were the first samples collected since the end on the 1991-1993 flank eruption. Activity resumed at Etna's summit craters in July and August of 1995.

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Volcanologists at the Istituto Internazionale di Vulcanologia-Catania reported another episode (the 4th) of fire fountaining at North-East Crater of Mt. Etna in the early morning of November 23, 1995.

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The C.N.R Istituto Internazionale di Vulcanologia in Catania reported a 7th episode of fire fountains at North-East Crater of Mt. Etna. The activity began early on the morning January 25, 1996. The fire fountains lasted about 6 hours and pulsating jets of lava reached 1,000-1,300 feet (300-400 m) of above the crater rim. A blanket of scoria fallout extended from the vent to about 7 miles (12 k on the northeast flank of the volcano.

The start of the 8th episode of fire fountains at Mt. Etna began late on February 9, 1996.

 

This episode ended early on February 10, 1996. Pulses of lava shot 650 feet (200 m) above the crater rim. Lapilli fallout covered a narrow band from the vent to the shoreline, a distance of 15 miles (25 km away). A light ash fell on the town of Catania. Minor eruptive activity continued up to early morning of February 12, 1996.

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Mt. Etna, April 29, 1993.

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Etna has the longest history of documented eruptions of any volcano. The first reported eruption was in 1,500 BC.

Mt. Etna, May 31, 1983.

Information supplied by: http://volcano.und.nodak.edu