What do earthquakes tell scientists about the history of the planet?

• A. Earth's climate is constantly changing.
• B. The continents of Earth are continually moving.
• C. Dinosaurs became extinct about 65 million years ago.
• D. The oceans are much deeper today than millions years ago.

Answer: (B)

Earthquakes reveal that Earth's lithospheric plates are constantly moving, which shows continents drift over time. The energy released by earthquakes occurs where plates interact—pulling apart, colliding, or sliding past one another—so mapping where earthquakes happen outlines the edges of these moving plates. Over long periods, this plate movement reshapes where continents sit, how they connect, and how mountains and oceans form. So earthquakes are telling scientists that the landmasses themselves are not fixed; they have been and continue to be carried across the globe.

The other ideas don’t fit as well. Earthquakes don’t directly tell us about climate change, and they aren’t the primary evidence for the timing of dinosaur extinction. Likewise, while tectonic activity does influence ocean depth over long times, earthquakes by themselves aren’t the main indicator that the oceans are deeper now than millions of years ago.