Updates December 1997

Etna Live-cam photos of 17 December 1997 SE Crater in eruption with lava flowing down n its southeastern flank. The upper photos were taken at 0652 and 0653, respectively, the lower ones at 1022 and 1102. Last frame shows steaming active lava flow on southeastern (right) flank of SE Crater. Other recent flows are well visible as dark lobes contrasting against the snow. Etna Live-cam photos of 12 December 1997 Intense explosive activity from Bocca Nuova (left) and SE Crater (right); frames were taken at approximately 1750, 1758, 1812 and 1958 local time. Second and third frame show large bursts of bombs from southeastern vent in Bocca Nuova, the other frames show fountains from SE Crater and beginning of lava overflow on its southeastern flank. Etna Live-cam photos of 11 December 1997 Four views of Etna's summit taken at 0810, 0825, 0830 and 0903 local time (approximately), showing lowered active cone in SE Crater and ash emissons from same cone and Bocca Nuova. Upper part of 9 December lava flow is visible on the right flank of SE Crater. Four views of Etna's summit, the two at left during the day (at 1045 and 1552 local time) and those at right during the evening (at 1750 and 1812 local time), showing recent and active lava flows from SE Crater. Etna Live-cam photos of 9 December 1997 Emission of a larger lava flow on the southeastern flank of SE Crater. Top left: 1705 local time; top right: 1709 local time; bottom left:1610 local time; bottom right: 1620 local time. Note strong incandescence at Bocca Nuova (left) in last frame. Etna Live-cam photos of 5 December 1997 Top left: Etna live-cam image showing summit cone and SE Crater with large intracrateral cone (1135 local time). Top right: Zoom on SE Crater showing more detail of its eruptive cone (1245 local time). Bottom left: Close-up of the eruptive cone within SE Crater (1247 local time). Bottom right: Zoom on eastern half of Bocca Nuova and the collapsing remainder of the 1964 cone (1250 local time). Top left: Bocca Nuova and SE Crater at dusk; no incandescence visible (1652 local time). Top right: Explosive activity at SE Crater begins to increase (1702 local time). Bottom left: Large explosive blast from SE Crater (1705 local time). Bottom right: Lava flows down rear (northeastern) side of central cone in SE Crater (1725 local time).

SE Crater, 22 December 1997 Top left is a zoom on SE Crater taken during daylight; the other shots were taken at dusk and show the development of a vigorous lava fountain from SE Crater. Lava flow on SE flank of the cone is well visible in lower right. SE Crater, 18 December 1997 Top left: General view of summit cone and SE Crater at 1205 h local time. Top right: Zoom on SE Crater's active intracrater cone at 1655 h, showing Strombolian explosion and lava flows spilling down SE slope of SE Crater's main cone. The two photos at bottom are of 1701 and 1706 h, respectively, showing intracrater cone in vigorous explosive activity and lava flows on SE flank. Intracrateral cone, 16 December 1997 Zoom on the active cone within SE Crater on 16 December 1997 at 1113 local time, showing renewed growth in the summit area of the cone, particularly on its eastern side (right).

23 December 1997

The episode of strong lava fountaining from SE Crater yesterday afternoon lasted about 1 hour after which the activity returned to more normal levels. Strong Strombolian explosions occurred throughout the night, and lava emission on the SE flank was continuous. The length of the active lava flow was similar to that of other recent flows. The uppermost image at right shows four frames grabbed from the IIV telecamera yesterday, the first showing details of SE Crater at daylight while the other document the initial stages of the strong fountaining episode at dusk.
This is the last update of 1997; updating will be resumed after the first week of January 1998.

22 December 1997

An episode of vigorous lava fountaining from SE Crater began shortly after dusk today (at about 1715 h local time) and is continuing, although with decreasing intensity, as of 1750 h. Fountains may have risen as high as 200 m above the active intracrater cone. A lava flow was erupted onto the SE flank of SE Crater but appeared to be no longer than about 200 m, similar to other recent flows. I hope to have some photos from the IIV Etna telecamera available tomorrow.
Over the weekend, SE Crater and Bocca Nuova had continued to erupt in a "normal" manner, with lava flow emission from SE Crater onto its SE and SSE flanks. Explosive activity at the intracrater cone was near continuous, with bursts of bombs occurring every few seconds. The cone has regained the height lost in the intense activity after 5 December, and is strikingly regular when seen with binoculars from Palazzo delle Scienze. Lava flows did not extend further than a few hundred m from the crater rim, and the mass eruption rate is assumed to be stable in the past few days. A spectacular feature is the southernmost lava flow which shows beautifully developed levees.

18 December 1997

While eruptive activity at SE Crater and Bocca Nuova has continued without significant changes, two earthquakes have been felt in the Etnean area early this morning. News reports put the epicenter at Maletto, Milo and Zafferana which are villages located far from each other on the NW, SE and E flanks of the volcano. There is no clear relationship between the tremors and the eruptive activity which shows no appreciable change since yesterday.

17 December 1997

Etna's summit was visible from Catania for several hours this morning, and the IIV telecamera is transmitting good images of the summit craters. The lava flows erupted from SE Crater during the past few days are still confined to the southeastern flank of the cone. None of the new flows appears to have extended as far as the 9 and 12-13 December flows. Vigorous explosive and effusive activity was documented by the telecamera this morning at dawn (see photos at upper left). Renewed growth of the intracrateral cone was captured in a zoom of the IIV telecamera yesterday morning (see frame at right).

16 December 1997

Bad weather has precluded systematic observations of Etna today. Brief glimpses of the summit area yesterday evening revealed continued lava effusion down the S and SE flanks of SE Crater, but the extent and direction of the active flows could not be determined. For the moment, the Rifugio Torre del Filosofo does not seem endangered by the increased effusive activity because the terrain below the S and SE slopes of the active cone are dipping slightly towards SE.

15 December 1997

The activity over the weekend has been very vigorous, with more lava flows from SE Crater and strong bursts from the explosive vents in SE Crater and Bocca Nuova. A lava flow erupted on late 12 or 13 December onto the southeastern flank of SE Crater extended far beyond the base of the cone reaching a length similar to that of the 9 December flow. The new flow, however, passed only a few hundred m away from the Rifugio Torre del Filosofo. New voluminous lava emission down the SE and S flanks of SE Crater was observed on the evening of 14 December although clouds hampered visibility. Several brightly incandescent lobes of lava were spilling down the steep flank of the cone, and they appeared to be directed more southward than previous flows, which means, more towards Torre del Filosofo.
The emplacement of longer flows than previously during the current eruptive cycle of SE Crater means that the effusion rate has increased and flows of this length may be dangerous to the building at Torre del Filosofo which stands about 1 km from SE Crater. Today, the view of the summit (both from Catania and from the telecamera) is hidden by clouds.

12 December 1997

Vigorous activity at Bocca Nuova and SE Crater is continuing, with lava flows spilling over the southeastern rim of SE Crater and occasional high bursts of incandescent bombs from Bocca Nuova's southeastern vents (see images of the IIV telecamera at upper left). Last night, a lava flow from SE Crater extended to the SE base of the cone; at the time of writing (1930 local time = GMT+1), several brightly incandescent spots are visible on the upper slope of the cone, indicating ongoing lava outflow. Some of the Strombolian explosions from SE Crater are particularly large. Bocca Nuova's activity appears much stronger than during the past 17 days but is intermittent.

11 December 1997

Splendid weather this morning has permitted clear views of Etna's summit and recent changes at SE Crater. The lava flow erupted on the evening of 9 December is well visible, contrasting against freshly fallen snow. Seen from Palazzo delle Scienze (which is a different view than that of the IIV telecamera, more from the SE), this flow is seen to extend much farther downslope than previous flows on the SE flank of the cone, but its front is still several hundred m from the steep W flank of Valle del Bove. Movement of the flow has apparently stopped (no steam is visible at the contact of the flow with the snow). Two smaller, equally inactive lava lobes were erupted onto the SE flank of SE Crater's cone, down about two thirds of the cone's flank. The active central cone appears to have lost some height during the strong explosive activty of the past few days; Strombolian activity is still vigorous and at times accompanied by weak ash emissions. Strong gas emission is occurring from NE Crater and Bocca Nuova.
Today evening, lava effusion onto the SE flank of SE Crater is continuing. The two night views of the telecamera in the composite image at left show lava emission and Strombolian activity from that crater and fluctuating glows above Bocca Nuova.

9 December 1997

A more significant lava flow was erupted from SE Crater on the late afternoon of today, accompanied by vigorous explosive activity at the intracrater cone and within Bocca Nuova. The activity was well documented by the IIV telecamera (see scans from the telecamera at left). The SE Crater lava flow has overridden previous flows on the SE flank of the cone but appears to be longer.
Activity on the evening of 5 December was documented with the IIV telecamera until bad weather hid the summit from view. At dusk, the activity of SE Crater increased, and shortly after 1700 h, strong explosions heralded the emission of a lava flow to the northeastern side of the intracrater cone. Strong incandescence appeared at times over Bocca Nuova. On the evening after, Strombolian explosions occurred at intervals ranging from 1 to 5 seconds, with some jets rising up to 200 m above the cone's summit. No lava flow was visible. A weak glow was occasionally visible over Bocca Nuova.

5 December 1997

Observations with a small telescope from the roof of the Palazzo delle Scienze in Catania on the evening of 3 December and the morning after revealed vigorous Strombolian activity at SE Crater and significant growth of its central conelet. The very symetrically shaped cone is now much higher than the surrounding crater rims and sits on top of a shield-like lava field. No overflows of lava onto the outer flanks of SE Crater have occurred since the last snowfall on early 3 December. The cone is well visible in a series of photos taken today from the telecamera of the Istituto internazionale di Vulcanologia which show a general view of the summit cone and SE Crater, a SE Crater close-up, a zoom on the eruptive cone within SE Crater and a zoom on the eastern part of Bocca Nuova with the remainder of the 1964 cone (see 5 December images at left).
A swarm of 11 tectonic earthquakes (the largest having a magnitude of 3.4) occurred below the SE flank of Etna on 3 December, in an area known as "Piana del Vescovo". The hypocenters of these earthquakes were reportedly "very deep" (but no exact figures were given in the local newspaper reports on which source this information is based).