A drone took video of the giant split as it flew over the area in northwestern Mexico.
The crack is nearly a half-mile long, 30 feet deep, and 16 feet across.
Sky News says some scientists blame the San Andreas is to blame, but the University of Sonora believes an underground stream may have caused the cave in.
Farmers and other workers are having to find ways around the hazard and there are worries that others may form in the area.
One newspaper says farmers in the area may be to blame. Reports claim tried to trap rainwater with a homemade levee. They think its failure could have created the underwater stream but there isn’t any proof.
Researchers plan to study the gap further.
More here and video below.
http://youtu.be/G8rNUASnO1E