n.a depression in the ground communicating with a subterranean passage (especially in limestone) and formed by solution or by collapse of a cavern roof
As the water leveldrops, largesinkholesappearalong the shores (undermininginfrastructures such asroadsandBridges) and farming lands are full of cracks.
"Some theories say that small black holes in globular clusters should sink down to the center and form a medium-sized one, but our discovery suggests this isn't true, " said Daniel Stern, an astrophysicist at NASA's Jet Propulsion Laboratory in Pasadena, Calif.