The ship sank in waters 1100 – 1500 m deep, bringing down with it approximately 185000 L of diesel, 24000 L of lubricants, 1200 L of gasoline and all the machinery, equipment and furniture that was onboard. Its environmental impacts are still unknown and are being closely monitored.
There are not many options available to clean up oil spills in icy seas. Some of them, such as burning or using chemical dispersants, are especially problematic for the remote and near-pristine environment of the Southern Ocean. The M/S Explorer sank in a region of rich biodiversity. 2500 birds, mostly penguins, have been sighted in the vicinity. In addition, very little is known about how oil spills impact the millions of micro-organisms that live on the underside of sea ice. These organisms form the base of the Antarctic food chain and their contamination could possibly have far-reaching ramifications on the Antarctic food web.
The M/S Explorer is a veteran of the polar cruise ship trade, purpose-built to operate in extreme polar environments, and manned by an experienced crew. It is one of the most well-known and well-trusted of the over 40 vessels that take tourists to Antarctica.
A discussion of these issues can be found on the website of the Association of Polar Early Career Scientists (APECS):
Photo credits: Chilean Navy, via Associated Press