Tectonic plates

Scientists find massive crack under Atlantic that could spark devastating earthquakes soon

New tectonic fault identified 200 kilometers southwest of Portugal may explain historic Lisbon earthquakes and pose future tsunami risks.

Ruins of the Igreja do Carmo in Lisbon, ruined by the 1755 earthquake in Portugal.
 Thingvellir, Pingvellir canyon, two tectonic plates colliding.

Submerged tectonic plates? Scientists find anomalies deep within Earth's mantle