Tuesday, September 21, 2010

BP / Gulf Oil Spill - Cumulative Oil Slick Footprints

Thought it might be interesting to take a look at the work done by others on the BP / Deepwater Horizon oil spill in the Gulf of Mexico, and compare SkyTruth's total cumulative oil slick analysis to theirs. Here is our analysis, based on visual assessment of dozens of satellite images acquired from late April through mid July:

Cumulative BP / Deepwater Horizon oil slick footprint (red). Analysis by SkyTruth.

And here's the official analysis done by NOAA, using many of the same satellite images, but also including many full-resolution radar satellite images that the public did not have access to (the US doesn't operate any civilian radar satellites, so the radar images were purchased from foreign companies that don't allow NOAA to "redistribute" the images):

Cumulative BP / Deepwater Horizon oil slick footprint (orange). Analysis by NOAA, compiled by SkyTruth.

The folks at ROFFS (Roffer's Ocean Forecasting Service) also analyzed satellite images and other oceanographic data throughout the duration of the spill, and just released their preliminary cumulative analysis. We don't have it digitally yet, but we've clipped their graphic to roughly show the same area in our two Google Earth-based maps above:

Cumulative BP / Deepwater Horizon oil slick footprint (brown). Analysis by ROFFS.

Overall, the NOAA and ROFFS analyses are in general agreement. The total NOAA oil-slick footprint covers 46,299 square miles (119,915 km2). SkyTruth's analysis is similar except for our inclusion of possible oil sheen entrained in the Loop Current and entering Florida Straits late in May, before a large clockwise eddy (Eddy Franklin) got organized and effectively kept the slick bottled up the the northern Gulf for the remainder of the summer. The total oil-slick footprint in our analysis is 68,000 square miles (176,119 km2).

BP / Gulf Oil Spill - This Dragon Is Dead

Finally -- after killing 11 people, injuring 17 others, spewing 172 million gallons of oil and untold amounts of natural gas into the ocean, and tormenting the entire Gulf of Mexico region for almost 5 months -- the BP / Deepwater Horizon dragon has been declared officially dead by the US Coast Guard. After some tense last-minute complications, a relief well successfully intersected the failed Macondo well 13,000' beneath the seafloor last Thursday (September 16). Cement was pumped into the base of the Macondo well, and pressure testing conducted over the weekend confirmed that this cement job had sealed the well.

Hallelujah. It's a relief, but the BP / Deepwater Horizon Oil and Gas Disaster is far from over. There is a lot of work to do to fully measure and understand the impact of this event, to monitor its impacts over time, to apply all the lessons learned to our offshore drilling practices, and to help the Gulf ecosystem and communities recover.

Sunday, September 12, 2010

San Bruno Pipeline Explosion

Fire consumes neighborhood in San Bruno, California, following rupture of a natural-gas pipeline. Photo by Paul Sakuma / Associated Press, courtesy Los Angeles Times.

Tragic news coming out of California as the death toll has now reached 7, with 6 people still missing, from the massive pipeline explosion and fire that consumed 37 homes in San Bruno, just south of San Francisco (map and photo gallery from Los Angeles Times). The 30" diameter high-pressure natural-gas pipeline, installed in 1956, ruptured shortly after 6pm local time on Thursday, September 9.

The explosion was so strong that USGS seismometers recorded it as a Magnitude-1.1 earthquake.

Map showing location of San Bruno explosion and fire. San Andreas Fault shown in purple. Speculative minor fault or fracture zone, interpreted by SkyTruth from Google Earth imagery, shown in yellow.

What caused this pipeline to rupture? Nobody knows yet, but this is of course a very seismically active region with notoriously unstable geology. The pipeline failure happened at the intersection of Earl Avenue and Glenview Drive, at the head of a steep ravine. Our analysis of the imagery in Google Earth (high-resolution aerial survey photography) suggests this ravine may follow the trend of a fracture zone in the bedrock that is roughly parallel to the San Andreas Fault, which lies just 1,000' to the west of the blast site. It is possible that stress was steadily and incrementally building on the rigid pipeline as strain accumulated across this minor fault or fracture zone, or as soil gradually slid down into the ravine. Consider this analysis to be preliminary and highly speculative.

UPDATE 9/13/10 @ 11am - Check out the Pipeline Safety Trust's web page for this disaster, and for more information on causes of pipeline failure, other incidents, and pipeline regulation and oversight.

Friday, September 3, 2010

Hurricane Earl and Virginia Offshore Drilling (Lease Area 220)

What if Virginia had active offshore oil and gas development?

We got the latest wind-history data from NOAA, showing the extent of hurricane-force and tropical-storm-force winds as Hurricane Earl moved along the East Coast today. We overlaid these "wind envelopes" on the proposed drilling area designated Lease Area 220. Here is the result, using a satellite image of the storm taken at 3pm EDT as backdrop:

Most of the drilling area would have experienced hurricane conditions today. The western part, along with the coastal support facilities onshore - pipelines, storage tanks, refineries, etc. - would have faced tropical storm conditions.

Here is the source for the wind history data, current through 11am EDT today. We'll update this map as more complete wind-history data become available:

Mariner Energy Gas and Oil Rig - MODIS Imagery, September 2, 2010

Fighting fire on the Mariner Energy platform in Vermilion Block 380, Gulf of Mexico, September 2, 2010. Photo by Greenpeace. More photos here.

Here at SkyTruth we finally got NASA/MODIS satellite imagery taken yesterday of the Gulf of Mexico, covering both the BP/Deepwater Horizon/Macondo well site and the location of the Mariner Energy platform that caught on fire yesterday morning while workers were painting it. Everyone was rescued and the fire was extinguished later that day. Early reports of a growing sheen of oil in the water were later retracted by the Coast Guard, and the seven wells under that platform have reportedly been shut in and are not leaking.

MODIS/Terra satellite image showing Mariner Energy platform (magenta cross) relative to BP spill site (yellow cross). Inset shows MODIS/Aqua imagery of the platform location taken an hour or so later.

NASA reported that the MODIS / Terra image taken at about 1pm local time showed a small plume of smoke from the burning rig, but the alleged plume is located about 40 miles northwest of the stated platform location, which we have verified by overlaying government GIS data for the locations of all oil and gas platforms in the Gulf. An offshore weather station on a Shell oil platform in the general vicinity reported wind consistently from the east to east-southeast. So we're not sure what that reddish-brown blotch is that caught NASA's eye - possibly a large patch of Sargassum, although it does seem to throw a shadow like the adjacent clouds, so maybe 1) it is a different smoke plume, or 2) everyone has misidentified the Mariner platform, which is very unlikely. Another little Gulf mystery.

BOTTOM LINE: We don't see anything on the Terra image to indicate either smoke or oil slick around the Mariner platform location, but it is pretty cloudy. The Aqua image taken at about 2pm local time (inset) is clearer, but we don't see anything unusual on it either. We'll keep looking at the area for the next few days but this seems to be just another one of the 100+ "run-of-the-mill" fires and explosions that are reported on Gulf oil and gas platforms every year.

Thursday, September 2, 2010

Mariner Energy Gas and Oil Rig - Location Map

Here's a map showing the location of Mariner's burning rig relative to BP's infamous Macondo well (still only temporarily plugged, awaiting a final "bottom kill" operation). The Mariner gas and oil rig is situated near the edge of the continental shelf, 100 miles off the Lousiana coast, 240 miles west of Macondo, in a water depth of 340 feet (surprisingly shallow at that distance offshore):

(Click on map for full-sized version)

It's busy out there. We've overlain active oil and gas platforms (orange dots) and oil and gas pipelines (green lines). Seafloor bathymetry is shown in shades of blue. All that rumply-looking stuff is the broad belt of salt domes and basins that makes the Gulf a really unique place, geologically and biologically.

UPDATE 9/2/10 6pm EDT - The Washington Post is reporting that the fire has been extinguished, and the 7 wells have all been successfully shut in (i.e., closed) and are not leaking. The Coast Guard is backing off their earlier report of a small oil slick. We're still waiting for today's NASA / MODIS satellite imagery to become available for download, but NASA has already published one of the images showing a small plume of smoke from the burning platform earlier this afternoon. We'll take a look at the images acquired for the next few days as well.

Oil Rig On Fire Off Louisiana Coast

US Coast Guard photo of burning Mariner Energy platform off Louisiana, 9/2/10. Source: AP via Miami Herald.

Breaking news - we just learned that an oil platform operated by Mariner Energy about 100 miles off the Louisiana Coast is on fire. 13 workers, who were on board when an explosion occurred about 9am Central time today, have been rescued from the water; one was injured.

The platform (Vermilion Oil Platform 380) is in water about 340 feet deep, 200 miles west of BP's Macondo well that caused this year's massive oil spill.

The Coast Guard is reporting a one-mile-long sheen of oil is spreading from the platform. It's unclear how many wells are at this platform, which produced an average of 9.2 million cubic feet of natural gas and 60,000 gallons of oil and liquid natural-gas condensate per day during the last week of August.

Based on these numbers we think the potential for a major oil spill is low, but we still don't know what caused the explosion.

SkyTruth is working to get satellite imagery of the area. We'll let you know as soon as we see anything. Follow us on Twitter to get the latest updates.