5 June 2010

BP: No Subsurface Oil Plumes In Gulf- Wrong

Posted by Dan Satterfield

There’s been a lot of talk about plumes of oil beneath the surface in the Gulf of Mexico. I haven’t said anything here or on air about it because  I wasn’t sure who was right. BP says there are not. Several sources in the media say they’ve been told there are.

The evidence now seems pretty conclusive that there are indeed subsurface plumes of oil.

Here is the evidence.

Exhibit One. Measurements of Inorganic carbon and dissolved oxygen made using a device called a CTD.

Exhibit ONE is from Dr. Samantha Joye a scientist from the Univ. of Georgia. She is on board the Research Vessel Walton Smith in the Gulf. Her group is following up on the discovery made by researchers from the Univ. of South Mississippi onboard the PELICAN that deep-water plumes were evident.

Using equipment on board to measure properties of deep ocean water, they have found a plume of oil about 3.5km  wide and 16 km long to the SW of the Deepwater Horizon leak. Other groups have discovered a plume to the NE of the spewing well head.

Using water samples they have confirmed that the water at the depths where the instruments are seeing strong indications of oil is in fact very oily!

Dr. Joye is writing a blog of their observations and it is well worth a read.

Now for Exhibit TWO.

We go to the University of South Florida’s Ocean Circulation Group.

They decided to run a numerical ocean model to test what would happen to oil released at say 1200 meters beneath the surface. Where would it go. Would it stay there, or would it rise. If it stayed deep, what shape would the plume make?

So here’s what they found:

Model forecast of oil released since April 20 at 1200 meters depth. Plumes to the NE and SW of the well are indicated. Ctsy. Ocean Circulation Group U.S.F. Click image for more model data from the OCG.

This model data is in sigma levels, but you can interpret it easily. Blue is deep and red is near the surface. The gray circle is the site of the modeled release which is where the gusher in the Gulf is located. The actual well is about 1600 meters down.

Do you see what I see? A plume SW and another NE at great depth.

I thought so.

Science is about observations and predictions. We have both here. They match up pretty well.

Unless someone can show some decent evidence to the contrary, the assumption that there are deep-water plumes of oil in the Gulf and that they are coming from the broken well head, is on pretty solid scientific ground.