Select the correct pairing of an event with its effect on the earth's surface.
a.
flood: a rock mass sliding down a mountainside onto the earth's crust
b.
tornado: masses of ice that move soil across the earth's crust
c.
glacier: a piece of rock collides with the earth's crust
d.
volcano: the eruption creates new land on the earth's crust

D. volcano: the eruption creates new land on the Earth's crust

Explanation:

The volcanic activity is crucial for the formation of new crust on the planet, be it oceanic or continental one. Through the eruptions, the volcanoes release pyroclastic material, and more importantly and in much higher amounts, they release lava. The lava quickly starts to cool off on the surface of the Earth as the temperature is much lower. As it cools off, the lava becomes igneous rocks, more specifically extrusive igneous rocks. These new rocks are actually the new crust on the Earth's surface, thus increasing the land mass.