Is gravity equal everywhere on the planet?

ArabiaWeather.com - Residents of Hudson Bay in Canada live at very low levels of gravity, estimated to be three times less than normal. This phenomenon was discovered in 1960.

Scientists put forward some theories that explain the reason for the spread of gravity related to the mass of Hudson Bay and the melting of snow since the last ice age 10,000 years ago, and between the heat transfer in the Earth's mantle, which is a layer of molten rock "magma", and requires the return of Earth's gravity there for thousands of years.