Terra MODIS True Color RGB, 28 Feb 2021

Mount Etna very active in February & March 2021

16-28 February and 2-11 March 2021

Terra MODIS True Color RGB, 28 Feb 2021
Terra MODIS True Color RGB, 28 Feb 2021

In February 2021, regular Etna eruptions were observed from space.

Last Updated

26 March 2021

Published on

03 March 2021

By Jochen Kerkmann (EUMETSAT) and HansPeter Roesli (Switzerland)

On 16 February 2021, Etna started a series of very spectacular lava-fountaining eruptive episodes, known as paroxysms. The short, but violent paroxysms, produced spectacular fireworks of lava fountains and blanketed part of Sicily with black ash.

In total, eight short paroxysms (with durations of around 2-3 hours) were observed by Meteosat-11 in the period 16-28 February (Figures 1, 2 and 3), under perfect viewing conditions, i.e. no clouds obscuring the scene.

Mosaic of Meteosat-11 Ash RGB images for all 8 paroxysms
Figure 1: Mosaic of Meteosat-11 Ash RGB images for all eight paroxysms. The images capture the volcanic plumes about 2 hours after the start of the eruption.
Mosaic of Meteosat-11 Aimass RGB images for all 8 paroxysms
Figure 2: Mosaic of Meteosat-11 Aimass RGB images for all eight paroxysms.
Figure 3: Fast movie of eight Etna paroxysms between 16 and 28 February (Meteosat-11 Ash RGB).  Each eruption is followed for 3-4 hours.

Each time the volcano sent lava hundreds of metres (or even more than 1000 m) high in the sky creating beautiful sceneries (especially in the night), it also injected a fair amount of ash and sulphur dioxide (SO2) in the atmosphere.

In the Ash RGB (Figures 1 and 3) the ash and SO2 plumes are seen in red/green shades, respectively. In the Airmass RGB (Figure 2), SO2 clouds appear with red hues — ash is not different from water cloud in the Airmass RGB.

Note that, due to hot lava flowing down the mountain, Mount Etna is clearly visible as hot spot in all eight cases (dark magenta pixels in the Ash RGB, black spots in the Airmass RGB).

The first of eight eruptions occurred on 16 February at around 16:00 UTC (17:00 local time), producing a tall ash plume that rose to up to approximately 10 km elevation (30,000 ft) above sea level, according to Volcano Discovery reports. The plume quickly moved southward driven by very strong upper-level northerly winds (Figure 4).

Me-11 24hr Microphysics 16 Feb
Figure 4: Meteosat-11 24h Microphysics RGB with geopotential 300 hPa overlaid, 16 Feb 18:00 UTC. Credit: EUMeTrain

Only 32 hours later, Etna produced another impressive eurption (see 17 Feb image in Figures 1 and 2). The volcanic plume rose again to about 10 km height. This time strong winds carried the SO2 plume in a south-easterly direction towards Libya.

While creating the animation of the 2nd paroxysm, we observed, in real-time, the 3rd paroxysm, which started on 19 February at 08:30 UTC (day-time eruption), exactly 33 hours after the 2nd eruption. The impressive eruption column, with circular umbrella cloud, could be observed from many places in Sicily. The high-level SO2/ice plume travelled eastward towards Crete, where it arrived in the morning hours of 20 February. Sentinel-3A OLCI captured Etna at 09:12 UTC on 19 February, around 40 minutes into the eruption (Figure 5).

Sentinel-3B OLCI True Colour 19 Feb 2021
Figure 5: Sentinel-3A OLCI True Colour, 19 February 09:12 UTC.

 

In the following days, Etna continued its regular activity, with a new paroxysm every 36-48 hours. Inhabitants of Sicily and experts around the world started to focus on the volcano and  predictions started to be made about when would be the next eruption.

Eruptions four, five, six and seven were again spectacular night-time events, very similar to the previous paroxysms. Only paroxysm number six (image from 23 Feb, Figures 1 and 2) was a bit different: it occurred only five hours after paroxysm number five, and it released a pure ash plume. As the high-level winds had changed to easterly directions, all the plumes from these eruptions headed towards western Sicily and the Tyrrhenian Sea.

Figure 6 shows two instances of the volcano plume at 00:33 UTC and 01:25 UTC on 23 February, captured by the Day-Night-Band (DNB) of VIIRS on NOAA-20 and Suomi NPP, respectively.

VIIRS and Day-night Band 23 Feb 2021
Figure 6: Day-Night-Band (DNB) of VIIRS at 00:33 UTC (left) and at 01:25 UTC (right) on 23 February, captured by NOAA-20 and Suomi NPP.

The imagery is enhanced using Zinke’s method, which clearly highlights the moon-lit plume (three-quarter waxing moon). Note in particular the fine cellular structure of the plume at 01:25 UTC, a pattern found in Dust-Infused Baroclinic cyclone Storm (DIBS) clouds and a sign for interaction of the volcanic ash with water cloud.

The last lava fountain episode, or paroxysm, of February occurred in the morning of Sunday 28 February, after a longer interval than the previous seven. After roughly three and a half days, the awaited number eight episode of the series of paroxysms occurred Sunday morning around 9 am local time.

Figures 7 and 8 show close-up views of the ash/SO2 plume two hours after the start of the eruption. They show a higher-level ice/SO2 cloud (white in the True Color RGB, green in the Ash RGB) and a lower-level ash plume (brown in the True Color RGB, red in the Ash RGB). While the ash plume disintegrated quickly within a few hours, the SO2 plume travelled a long distance across the Mediterranean Sea towards Crete and further to the Middle East.

 

Met-11 RGB comparison

Airmass RGB compare1
compare2
 

Figure 7: Meteosat-11 Ash RGB (left) and Airmass RGB (right) on 28 February at 10:00 UTC.

Terra MODIS True Color RGB, 28 Feb 2021
Figure 8: Terra MODIS True Color RGB on 28 February. Credit: NASA

Further activity in March

Eruptions continued in March 2021, with very regular intervals. In the first two weeks of March there were a further four eruptions. The total number between 16 February and 11 March was 12, with very regular intervals between each of an average of 2.5 days.

After little more than two days after the eighth paroxysm, the ninth such episode of vigorous lava spewing from the volcano's SE crater occurred on the afternoon of 2 March (Figure 9) . It was remarkable for its long duration.

Figure 9: Meteosat-11 Ash RGB, 2 March 12:15 UTC-21:00 UTC

Less than two days later, the 10th paroxysm took place in the morning of 4 March (Figure 10).

Figure 10: Meteosat-11 Ash RGB, 4 March 07:00 UTC-19:00 UTC

Just another three days later, paroxysm number 11 was underway. According to the National Institute of Geophysics and Volcanology (INGV), the eruption column reached more than 10,000 m (30,000 ft) elevation (Figure 11).

Figure 11: Meteosat-11 Ash RGB, 7 March 06:00 UTC-14:30 UTC

On 9 March the 12th paroxysm started around 23:30 UTC and lasted more than three hours (Figure 12).

Figure 12: Meteosat-11 Ash RGB, 9 March 23:30 UTC- 10 March 12:30 UTC

The Japan Meteorological Agency (JMA), reported that the Etna SO2 plume travelled a long way, across Asia to Japan. This can be clearly seen in animations of the Himawari-08 Airmass RGB images, where the SO2 appears in red shades. Figure 13 is the longer loop in three-hourly time steps and Figure 14 is a shorter loop in 1-hour time steps.

Figure 13: Himawari-8 Airmass RGB, 8 March 18:00-11 March 09:00 UTC.
Figure 14: Himawari-8 Airmass RGB, 10 March 09:00-11 March 09:00 UTC.

On 12 March 2021, the volcanic plume was still visible in Meteosat-11 Ash RGB imagery (Figure 15, top left) and also detected in CIMSS-derived products (ash height, ash efffective radius and ash loading).

Met-11 Ash RGB and CIMSS product
Figure 15: Meteosat-11 Ash RGB (top left) and CIMSS-derived ash products, 12 March 2021 10:00 UTC. Credit: CIMSS/NOAA
 
 

Related content

Met-11 Ash RGB loops 16-28 Feb (various times and perspectives)
A Glowing Plume Over Mount Etna (NASA Earth Observatory)
Eruption of Mount Etna 19 Feb 2021 (CIMSS Satellite Blog)
Eruption of Mount Etna 24 March 2021 (CIMSS Satellite Blog)