Re: Black Hole on Earth, say what?
There is no such thing at the "Bermuda Triangle".
Gravity does vary slightly, depending upon the thickness and density of the underlying crust and mantle along with the lattitude. Here is a gravity map of the Earth, showing regions of greater and lesser gravity.
((http://apod.nasa.gov/apod/ap030723.html))
You will not that nothing here corresponds even slightly to the mythical "Bermuda Triangle".
David F Mayer