Oil Closes Another California Beach

Officials in Santa Barbara County, California, had to close another beach because of oil washing ashore from an as-yet unidentified source.  Summerland beach is located along the coast between the site of the Refugio State Beach pipeline oil spill back in late May, and the beaches of Ventura County that were also closed when tarballs began coming ashore a week after that.  Is the Summerland oil coming from some of the natural oil seeps in and around the Santa Barbara Channel?  Or is it coming from one of the offshore oil platforms in the vicinity?  

A beautifully clear Landsat-8 satellite image was taken on August 14.  Summerland is at top center on this sequence of images.  A faint slick several miles long dominates the center of the scene:

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Detail from Landsat-8 satellite image showing California coast around Summerland.
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Seven oil platforms and three passing vessels are noted. Platform A was the site of the infamous Santa Barbara Oil Spill of 1969.  The slick in this image appears to emanate from the same location as Platform A. 
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Locations of known natural seeps, and sample collection sites for oil slicks and tarballs, are shown.  Data from USGS / PCMSC. The USGS data show a “seep” or small cluster of seeps at the Platform A site.

It’s not clear to us if the “seeps” indicated by USGS on the data shown above are natural seeps that predate the installation of Platform A and the catastrophic subsea blowout and spill of 1969; or if “seep” in this case refers to the ongoing slow leakage of oil resulting from that blowout.  If you know, please write a comment below.  

This Sentinel radar satellite image taken yesterday (August 23, 2015) clearly shows the big metal oil platforms as rows of brilliant spots. The large dark patches are slicks — flat patches of water — but it’s not clear on this image if they are caused by seeps, variable wind, floating kelp, or (most likely) all of the above in this very dynamic place:

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Sentinel-1A radar satellite image, same area as above, taken on August 23, 2015. Oil platforms are bright spots; slicks (oil and otherwise) are dark patches. Image courtesy Copernicus / ESA.
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Radar image shwoing locations of oil platforms, as well as known oil seeps and sample locations from USGS / PCMSC. Image courtesy Copernicus / ESA.
Bottom line: We don’t see a clear culprit for the Summerland spill, but it might be worth flying over Platform A to see if the seepage there has recently increased for some reason.