The extent of the Deepwater Horizon oil spill, May 6, 2010.

The Deepwater Horizon oil spill over the GTA and surrounding region.

Paul Rademacher, a Google Maps engineering manager, has created an interesting app using Google Earth that lets people overlay the Deepwater Horizon oil spill over any area of the globe.

If the 6,500 square kilometre spill were centred over Toronto, it would also cover Oakville, Mississauga, Oshawa, Vaughan, Brampton, Ajax, Pickering, Aurora, Newmarket, Cobourg, St. Catharines, Niagara Falls, and Welland, plus dozens of other small towns, a large chunk of Lake Ontario, and thousands of square kilometres of farmland and forest.

You can read more about the spill, its size, and how it's being tracked on the National Oceanic and Atmospheric Administration (NOAA) website.

Hat tip to the Toronto Star's Map Blog