Geologists think that oceanic crust is different from continental crust because
A)seismic waves travel at different speeds through these layers.
B)oceanic crust is much thinner than continental crust.
C)S-waves don't travel through oceanic crust while they can through continental crust.
D)core samples reveal that oceanic crust is largely granite-like materials.

Question

Quizplus · Accepted Answer

Seismic waves travel at different speeds through oceanic and continental crust because the two types of crust have different densities and compositions. Oceanic crust is denser and thinner than continental crust, and it is composed primarily of basalt, a type of igneous rock. Continental crust is less dense and thicker than oceanic crust, and it is composed primarily of granite, a type of igneous rock. The different densities and compositions of the two types of crust cause seismic waves to travel at different speeds through them.

Geologists Think That Oceanic Crust Is Different from Continental Crust