Massive fire at oil depot in England

By Gordon Bridge, Hans Peter Roesli and Cecilie Wettre (EUMETSAT)

Massive fires raged at the Buncefield oil depot in Hemel Hempstead following a series of explosions early in the morning of 11 December 2005 (around 06:08 UTC) . Some 2,000 people had to evacuate the area, after the blast sent flames and smoke shooting hundreds of feet into the sky, damaging many homes and offices, shattering windows and blowing off doors.

The reverberations were felt up to hundreds of kilometres away in Europe, and the explosions could reportedly be heard as far away as the Netherlands and northern France. The huge conflagration blazed for three days before it was finally under control, and enormous smoke clouds spread in a large radius around the burning depot, turning the sky black for miles. Images from Meteosat-8 were in this case very helpful in tracking the dispersing clouds.

The top four images and animation below cover the period 06:00 UTC to 19:00 UTC on 11 December 2005, and comprise data from the Meteosat-8 High Resolution Visible (HRV) channel in combination with data from the 3.9µm channel.

The HRV animation clearly shows the black smoke plume emanating from the burning fuel depot and, elsewhere, white low clouds and valley fog (showing the presence of low level atmospheric temperature inversions). Such an inversion trapped much of the smoke below it, at around 1km, however, over the fiercely burning fire, the temperature of the smoke was so high that the column punched through the temperature inversion and rose to around 3km before spreading out into a large black cloud.

The wind at this higher level was more north-easterly in direction, hence the appearance of two plumes — the higher one moving to the south-west, the other (lower level) to the south or south east. Later on, there even seemed to be some movement of a plume to the north east.

Additionally, this low level temperature inversion is probably a key reason why the sound of the explosion was 'ducted' over the such very large distances as northern France and the Netherlands.

The 3.9µm channel is very sensitive to heat and clearly shows the hot spot, or fire, caused by the burning oil tanks. At 06:15 UTC there is a momentary appearance of a hot spot, shortly after the initial explosion (not shown in the movie sequence) with a second, more permanent and major fire showing up in the 10:15 UTC image.

The combination (RGB) images use the HRV data on all three (red, green and blue) colour beams and the 3.9µm data four on the red and green beams only.

The lower left image, as well as the second animation, are RGB composites based on the VIS0.6 and HRV channels and an inverse of the IR10.8 channel. The image is from 11 December at 11:45 UTC, while the animation spans over several days, and shows the huge black smoke cloud dispersing east, west, and southwards. The lower right image is composed of the NIR1.6, VIS0.8, and VIS0.6.