Scientists believe that is an example of an internal force that changes the earth’s crust. a. mining c. human development b. plate tectonics d. erosion

b. plate tectonics

Explanation:

   Plate tectonics is a theory originated from continental drift and ocean floor expansion. It was developed in 1960, and has become the most accepted among geographers and oceanographers.

    According to this theory, the lithosphere moves over the asthenosphere. The lithosphere, in turn, is divided by plates (called tectonic plates) and they slide because of convection currents within the Earth. The heat that comes from the core of the earth warms the mantle and makes the warmer parts rise. These parts cool and fall back down. It is these currents that slowly move the plates that form the earth's crust.

a mid-ocean ridge or mid-oceanic ridge is an underwater mountain range, formed by plate tectonics. this uplifting of the ocean floor occurs when convection currents rise in the mantle beneath the oceanic crust and create magma where two tectonic plates meet at a divergent boundary.a geomagnetic reversal is a change in a planet's magnetic field such that the positions of magnetic north and magnetic south are interchanged.

landlessness of ordinary people

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