Offshore Drilling: Spillustrations
SkyTruth is getting barraged by requests from people around the country who want to know what could happen if an incident comparable to the Montara / West Atlas oil spill happened off their coast. In response, we’ve generated a series of illustrations that superimpose the area of oil slicks, as shown on satellite images of the Timor Sea disaster, on various parts of the US including:
- Alaska (Bristol Bay)
- California (Eureka – Arcata)
- Florida (Tampa – St. Petersburg)
- Florida (Pensacola)
- mid-Atlantic (Chincoteague, Virginia – Bethany Beach, Delaware)
- mid-Atlantic (Virginia Beach, Virginia – Corolla, North Carolina)
These illustrations are not predictive spill models – they don’t take into account local winds, currents, shoreline configuration or bathymetry – but they do accurately portray what a Montara-sized oil slick would look like, as shown on some of the satellite images we’ve been collecting and analyzing for that ongoing event.
The Montara spill is now in its 45th day, as efforts to drill a relief well continue. Using the oil company’s estimate of 400 barrels per day, over 750 thousand gallons of oil have spilled since the blowout on August 21. Using an alternative estimate of 3,000 barrels per day that is based on the actual published flow rates of nearby oil wells, over 5 and a half million gallons may have been spilled so far.
It would be interesting to plot the size of the spill over time. The dispersant applications do not seem to have had an effect on the growth of the slick.
We're actually doing this, and are seeing lots of variability in the size and location of slicks over time: winds and currents are highly variable in the Timor Sea at this time of year. But our data stream – visible/infrared satellite imagery from the MODIS sensor carried by two NASA satellites – isn't consistent enough to do a very good job of spill tracking since we're relying on getting just the right sunglint pattern to detect and map the slicks, and that happens infrequently (about once a week).
Radar satellite images are much better for slick detection, mapping and tracking, but unfortunately the US does not operate any civilian radar imaging satellites. Access to the European Space Agency's radar imaging satellites, Envisat and ERS, is very limited, and images from Canada's Radarsat satellite are very expensive.
We'd love to see NASA build and operate a civilian radar imaging satellite so we wouldn't have to rely on other countries for pollution detection and tracking.