Covering oil spill from space takes group effort

The tragic oil spill caused by the bulk carrier MV Wakashio off the coast of Mauritius illustrates how satellite imagery and data analysis can be used to monitor events as they unfold.

In our last two blogs, we provided information on the size/location of the oil spill and plotted the Wakashio’s ill-fated voyage.

A month after the bulk carrier ran aground, the situation has entered a new phase. The front-section of the Wakashio was deliberately sunk, while the rear of the vessel remains on the coral reef. Attention will turn next to the clean-up operation, a process that will undoubtedly last a very long time.

Though the work is far from over, we wanted to highlight some of the companies with whom we collaborated to provide a rapid response. Ursa’s analysis applied algorithms to satellite imagery to detect the presence of oil in the water around the MV Wakashio.

The companies that supplied synthetic aperture radar (SAR) imagery included:

• Airbus

• e-GEOS

• European Space Agency (Sentinel)

• ICEYE

• Japan Space Imaging (JSI)

• SIIS

We also referenced optical imagery from our friends at BlackSky.

Another angle was maritime monitoring, which we performed using Automated Identification System (AIS) data from Spire.

These resources, combined with our in-house capabilities, allowed us to shed light on the situation.

The following is a list of our key takeaways, in chronological order:

• Plotted the Wakashio’s path July 25 as the ship veered out of the shipping lane and headed toward the Mauritius coast.

• Identified the time (July 25, 15:46 UTC) and the place the Wakashio struck the coral reef.

• Confirmed the absence of an oil spill July 29.

• Detected the presence of an oil spill August 6. Mapped its location and quantified its size (3.3 square kilometers).

• Determined the size of the spill had expanded to 27 sq km on August 11.

• Further analysis found significant impact around the Blue Bay Marine Park reserve, near the Pointe d’Esny, as well as 10 km north of the Wakashio along a stretch of coastline with large aquaculture farms.

• Minimal surface disturbance was detected 20 km north of the Wakashio around Ile aux Cerfs, a popular tourism spot (Figure 1).

Figure 1

• Identified the ships aiding with salvage and clean-up operations

• Confirmed the Wakashio split apart August 15

• Tracked a pair of boats towing the bow of Wakashio away from the scene August 19

• Measured the size of the spill on August 16 at 8.2 sq km in the vicinity of the Wakashio (Figure 2).

Figure 2

We shared these findings in real-time with the press and social media.

Others joining this effort include Planet and Vulcan Inc. (on behalf of the Allen Coral Atlas), both of which provided geospatial resources. For more information, read Planet’s blog on the topic.

We will continue to focus on the impact of the oil spill on the Mauritius environment, exploring ways to provide analysis in collaboration with others.