Satellite Image Anomaly in Gulf of Thailand

We’ve turned up some Landsat-8 satellite images from the area in the Gulf of Thailand, between Malaysia and Vietnam, where Malaysia Airlines Flight MH370 went missing a few days ago.  Landsat images, at 30-meter resolution, are much more detailed than the twice-daily MODIS images at 250m resolution.  The image inset in the map below shows detail from Landsat-8 image P127/R54, taken at 03:27 GMT on March 8.  That’s almost exactly 10 hours after air traffic controllers reported their last contact with Flight MH370 (at 16:41 GMT on Friday, March 7).

Nothing in this image jumps out strongly.  But there is a faint, diffuse, pale anomaly not far west of the general location where we estimate MH370 was when contact was lost.  It appears to be horseshoe-shaped.  

The very approximate center of this is located at 8.551422° N latitude / 102.680976° E longitude.

As best I can tell, this anomaly seems to be high-altitude cloud or smoke; there is an even fainter dark anomaly to the west that suggests a shadow.  But I have to say, this is quite speculative.  It might also be some kind of phytoplankton bloom or other ocean-color feature.  And if it is smoke, 10 hours seems like an awfully long time for it to hang around.  See for yourself: