Yesterday evening Shell reported sighting a 10-mile by 1-mile oil slick between two of their major deepwater oil production platforms, Ursa and Mars. This is located in the Mississippi Canyon area of the Gulf, 130 miles south of New Orleans and about 60 miles beyond the tip of the Mississippi Delta, in water about 3,200' deep.
Yesterday's low resolution MODIS/Terra satellite image of the area, shot at 16:50 UTC (10:50 am local time)
shows what appears to be a narrow, 17-mile-long slick in the vicinity
of the two platforms. We often see slicks from known natural oil seeps
that are about this size; some in the Green Canyon area to the west show
up well on this same image. Low clouds and their shadows are scattered
across the lower half of this view: