An oil spill this weekend that caught fire in Balikpapan Bay, Indonesia, claimed the lives of five fishermen. State authorities initially reported the fire was set intentionally by oil-spill responders in an attempt to burn it off, a claim that was later denied.
The bulk of the slick can be seen escaping the bay in these satellite images. In this first image, one of Planet’s Dove satellites has captured variations in the thickness of the slick. We can see narrow, dark tendrils of oil surrounded by the lighter sheen and thinner layers of the slick. In places, the edges of the slick appear dark in contrast to the cleaner water as the oil smoothes out the surface by suppressing small wavelets produced by the wind. Even though the thinner layer of oil isn’t directly visible, we can still see the textural effect it has on the water’s surface, reducing the amount of sunglint (glitter) reflecting off the water:
This often subtle difference in roughness between clean and oiled water is why the European Space Agency’s Sentinel 1 Synthetic Aperture Radar (SAR) is also an excellent tool for spotting slicks, as we can see in the image below. Radar distinguishes sharply between the smooth, oily water and the wind-rippled, clean water, and can see right through the clouds, giving us a clear view of the extent of the spill. This Sentinel 1 image was taken on April 1, one day before the Planet image, illustrating how the winds and current have moved the slick around:
Initially, authorities were zeroed in on a bulk cargo vessel, the Ever Judger, as the source of this spill. We can understand why — the PlanetScope satellite image from April 2 shows the vessel anchored in Balikpapan Bay almost directly on top of one end of the slick:
But officials from Pertamina, the Indonesian state oil company, have come forward to say the spill was caused by the failure of a pipeline beneath the bay. This pipe, installed in 1998, carries crude oil from a storage terminal on the west side of the bay to a refinery in Balikpapan. We’ve looked for maps showing the route of this pipeline and, so far, struck out. Based on examination of the latest high-resolution imagery of the area in Google Earth (from October 2016), and knowing the locations of the terminal and the refinery (thanks to Google Maps), we’ve sketched in our best guess at where this pipeline may be located:
If anyone has more definitive information on this pipeline, or the precise location of the failure, please share! Over the next few days we will continue to monitor this incident with satellite imagery, thanks to our friends at Planet and the European Space Agency.[UPDATE April 5 – Pertamina claims the spill resulted when the Ever Judger dropped anchor without authorization in Balikpapan Bay, dragging and breaking their pipeline.]