Q 01/05

Plate tectonics describes the movement of pieces of which layer of the Earth?

A) The lithosphere

B) The lower mantle

C) The outer core

D) The asthenosphere

Answer · why

A) The lithosphere

The lithosphere is the cool, rigid shell of crust plus uppermost mantle, and it is broken into plates. They can move only because the hot, semi-solid ...

Q 02/05

Which sea is an ocean in the making, still widening as the plates on either side pull apart?

A) The Black Sea

B) The Red Sea

C) The Caspian Sea

D) The Mediterranean

Answer · why

B) The Red Sea

The Red Sea. It fills the long, narrow gash that opened when the Arabian Peninsula was torn away from the continent beside it, as new sea floor began ...

Q 03/05

Which island country sits astride the Mid-Atlantic Ridge, so visitors can walk along the boundary between two plates?

A) Ireland

B) Iceland

C) Cape Verde

D) The Bahamas

Answer · why

B) Iceland

Iceland. Almost all of the ridge lies hidden deep under the ocean, but a hot spot beneath the island is thought to have piled up enough lava to lift t...

Q 04/05

Besides heat left from Earth's formation, what keeps its interior hot enough to drive plate tectonics?

A) Sunlight soaking into rock

B) Unstable atoms breaking down

C) Friction between the plates

D) The weight of the oceans

Answer · why

B) Unstable atoms breaking down

Unstable atoms breaking down. Uranium, thorium and potassium scattered through the rock give off heat as they decay, an estimated half of all the heat...

Q 05/05

The 2004 Indian Ocean tsunami began when a plate boundary ruptured off the coast of which Indonesian island?

A) Java

B) Borneo

C) Sumatra

D) Bali

Answer · why

C) Sumatra

Sumatra. Two plates had been stuck together offshore, storing up strain; when the boundary let go along more than 1,000 km, the seabed sprang up by se...