Mapping of natural methane seeps is required as part of the process of obtaining a drilling permit in the Gulf of Mexico. This is required because the "methane seep communities" are considered environmental "havens" as it were - you have to demonstrate you're not disturbing the critters. [My comment: There are ecosystems which can thrive around small natural seeps. But huge gushers like the BP blow out can kill everything in sight, especially given the large amounts of methane which have spewed from BP's well]. The process does not measure the rate of seepage but you would have some guess based on the areal extent of the communities. This report is filed with the MMS and should be available. I'm surprised and enterprising reporter hasn't requested a copy from the MMS. (Of course enterprising reporter might be an oxymoron in the modern era)

I attended a scientific talk about 20 years ago where the study results estimated about 1 million barrels of oil a year seep into the Gulf from natural seeps. Of course that is spread over a huge area on an entire year.

In response to the above post, blogger CD notes that page 16 of BP's Initial Exploration Plan for the well states:

There is no evidence for the existence of high-density chemosynthetic communities within 1,500 ft of the proposed well location.

Gasmiinder responds:

The statement regarding the chemosynthetic communities requires a seafloor survey - that's what I'm referring too where there will be a report available having mapped them (the partners will have copies of that report as well).

Gasmiinder adds:

Here is a copy from the webpage of a company that consults on the interpretation of the hazard surveys. It should give at least a feel for the level of information that is believed to be present in the data (meaning this is what they claim to be able to accomplish with the datasets):

• Assess seafloor conditions and stratigraphy, and geologic processes to evaluate well site locations

• Identify shallow gas and shallow water flow potential [my note: they are referring to shallow layers that could be hazards to drill through)

• Interpret and map geologic constraints, such as faults, gas vents, seafloor depressions and mounds, and any other geologic phenomena that are detectable with seismic data

• Identify potential chemosynthetic communities, archaeological sites, and man-made infrastructure and debris

• Assess mooring spread, anchor locations, and foundation zones

• Produce supporting maps to show water depth, topography, shallow structure, and seafloor and shallow geologic conditions and features in an area that may have an impact on drilling

• Prepare final reports needed for permit application to governmental and insurance bodies

So BP (and its partners in the well, Anadarko and Mitsui) would have maps of all of the nearby seeps which were there before well blew out.

In addition, there are logs of where BP's underwater submersibles (ROVs) have traveled since they arrived at the scene. Tracking the logs would show whether any ROVs had visited the current seep before today. If so - and my hunch is that they have - then the corresponding footage would show how big those seeps were previously.

Indeed, enterprising citizen journalists who have recorded and stored the footage from BP's underwater cams could compare the compass readings from the current feeds showing seepage to previous similar compass readings, and find the footage themselves.

NASA has also demonstrated that natural seeps show up in satellite images when photographed in sunglint. However, I am not sure whether the seep near the blown out well is big enough - or of the right chemical composition - to see from satellite images.