7.
The country of Japan consists of

several thousands of islands, of which Honshu, Hokkaido, Kyushu and Shikoku are the four largest. Japan's closest neighbors are Korea, Russia and China

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.