In the last hours Mount Vesuvius is under siege by several fires that are surrounding the mountain’s slopes, spreading for around 2 kilometers and forcing the evacuation of locals from their home (there are indeed several small towns built near the sleeping volcano). A giant smoke trail raised towards the sky and then propagated for kilometers , causing a rain of ash over all the Province of Naples and the Campania neighbouring regions (Molise, Abruzzo). “Just like an eruption” is the comment of many citizens: here below some photos pictured from the ground.
Copernicus Sentinel-3A satellites captured the event with both its radiometers. The first image below is an RGB processed with an OLCI acquisition, showing the wildfires on Tuesday morning (July 11th, around 09:00 UTC). The smoke trails are clearly visible during their spreading in the atmosphere.

On the other hand the Sea and Land Surface Temperature Radiometer thanks to its thermal bands can isolate the fires, allowing the detection and identification from the Space. The image below is an animation generated with two different images of the SLSTR instrument, both processed only with the F1 band (3472 nm) to which the fire is responsive, acquired in two separate and consecutive times.

In the two images the water is masked out, in order to show only the land response, then they have been projected on google earth: the fires are identified in black and the temperature scale is expressed in Kelvin. Normally forest fires temperature is around 600k but in this case we can see a maximum detected temperature of 359K: indeed SLSTR thermal bands have a resolution of 1 km, so the detected temperature can be assumed as an average temperature of 1 km^2 of land (and so lower than expected).
As we can see at the end of the day the wildfires were still in progress and they were still alive during the day after as well. The situation is critical, a real emergency with a large part of locals very concerned. The started fires are more than 100 and the reasons of those pyres are actually still not clear: we can probably consider them as arsons, fires deliberately set by human hands for, according to Mayor of Naples Luigi de Magistris, “criminal activities”.
Contains modified Copernicus Sentinel data 2017.
https://scihub.copernicus.eu/
Ref:
http://www.lastampa.it/2017/07/12/italia/cronache/napoli-assediata-dai-roghi-sul-vesuvio-come-uneruzione-k1Dqwrxs4NrcT6obutXZiM/premium.html#acquistaregistraaccedi
http://corrieredelmezzogiorno.corriere.it/foto-gallery/campania/17_luglio_11/vesuvio-morsa-incendi-6ed3c664-6634-11e7-9e95-9c00fba5df0c.shtml
http://www.meteogiornale.it/notizia/47768-1-vesuvio-maxi-incendio-sembra-eruzione-vulcano
https://weather.com/news/weather/news/evacuations-as-italy-wildfires-burn-near-mount-vesuvius
http://www.ilpost.it/2017/07/12/incendio-vesuvio-doloso/