The ongoing Deepwater Horizon oil spill has provided a rare scientific opportunity: for the first time, multiple satellite remote-sensing systems, from visible to infrared to radar, are providing daily images of a large area in the Gulf of Mexico. This systematic imaging is proving useful for measuring the size and location of oil slicks and sheen, and for estimating the rate of leakage from BP’s failed Macondo well.

It’s also demonstrating another important ability — here at SkyTruth we think we’ve discovered a small but possibly chronic leak from an oil platform located a few miles off the Mississippi Delta, unrelated to but not far from BP’s leaking well:

Time-series of images showing possible small leak from Platform 23051

We first mentioned this back on May 15. According to GIS data from the Minerals Management Service showing the locations of all fixed oil and gas platforms in the Gulf, the platform that appears to be leaking is identified by Complex ID # 23051. You can look up more info at the MMS website. According to MMS this platform was installed in 1984, and it is manned 24/7 (most platforms in the Gulf are unmanned). The sequence of satellite images above shows what appears to be a small oily slick emanating from the platform location on multiple dates, captured by several different satellite imaging systems. We’ve observed the slick on Envisat MERIS and ASAR images taken on April 25 and 26, and May 12, 18 and 31; on RADARSAT images taken May 8 and 11; and on COSMO-SkyMed images taken May 11, 14 and 15. (Pet Peeve Alert: These are all foreign satellites, operated by Germany, Italy, Canada. Radar imagery is the go-to tool for detecting and monitoring oil slicks, yet the U.S. does not operate a single civilian radar satellite. Instead, we’ve been buying radar images of this disaster from other nations. This is nuts.)

On May 27 a scientist from the University of West Florida was flying over the Gulf to investigate the BP oil spill, and noticed an obvious discharge plume coming from a rig – here is one of the pictures she took during that flight:

Discharge plume from rig in Gulf of Mexico, May 27, 2010. Photo by Dr. Enid Sisskin and Southern Alliance for Clean Energy.

This appears to be a small jackup drill rig actively drilling in relatively shallow water. The brown plume looks like it could be drilling mud. But along with the apparent oily leak from 23051 this discharge raises a few questions:

• How much chronic, day-to-day pollution is associated with offshore drilling?
• Who is doing the necessary oversight to minimize this pollution?
• How effective is this oversight?
• As our vast offshore infrastructure of platforms and pipelines ages, can we effectively identify small chronic problems before they turn into big problems?

All of these questions point to a readily available technical tool that can contribute, right now, to providing some answers: regular monitoring of the Gulf using satellite images from a variety of remote-sensing systems. If the U.S. had such a program we could systematically assess how common smaller pollution events are, and immediately respond in the event of sudden pollution emergencies like the ongoing BP spill, recent pipeline leaks, the offshore and coastal spills that resulted from hurricanes Katrina, Rita and Ike, and other time-critical incidents.

Much of the hardware and trained personnel that could implement a Gulf-wide monitoring system already exists, at the CSTARS facility housed at the University of Miami. CSTARS has their own satellite dishes and image-processing capability. They’ve been producing gigabytes of satellite imagery since the BP spill began on April 20. But CSTARS only gets activated for this work during emergencies. Maybe it’s time to extend that mission and conduct regular, routine, continuous monitoring so we can get a more complete picture of how well our nation’s publicly owned waters and offshore resources are being managed.