Today’s Envisat ASAR satellite radar image of the Campos Basin, covering the location of the Chevron / Transocean oil spill, shows no sign of an oil slick. It was taken at about 9:30 am local time.
However, the wind speed was fairly strong in the area at the time. According to the satellite scatterometer data collected by the ASCAT system, surface winds were blowing at 15-25 knots (8-13 meters per second). This is strong enough to overwhelm very thin oil slicks (the optimum wind speed for detecting slicks on radar images is about 3 – 10 meters per second):
So it is possible that very thin oil slicks remain in the area, but it is encouraging that we don’t see signs of thick oil… (more text and images after the break)
An ASAR image taken on November 11 under more favorable wind conditions (5-8 meters/sec) clearly shows a 20-mile-long slick originating near the location of the SEDCO 706 rig:
And this radar image taken on November 14 shows a 27-mile-long slick on the site. Sea-surface wind speed measured in the vicinity was favorable in the morning but excessive (13-15 meters/sec) in the evening, so the thinnest parts of the slick may not be visible on this image:
We are cautiously optimistic that this spill has been brought under control. We’re hoping for a few more radar images in coming days, taken under moderate wind conditions. We will update you here when we see anything interesting.