Earthquakes and Society

These flashcards cover key terms and concepts related to earthquakes, plate tectonics, and geological phenomena discussed in the lecture.

Earthquake Foci

The specific points within the Earth where seismic activity originates.

Plate Tectonics

The theory explaining the movement of the Earth's lithospheric plates on the semi-fluid asthenosphere.

Wadati-Benioff Zones

Narrow zones in the Earth's crust where earthquake foci become gradually deeper, often associated with subduction.

Subduction

The process by which one tectonic plate is pushed down into the mantle beneath another plate.

Asassess the depth of seismic activity

Shallow hypocenters typically occur within the upper 30 km of the Earth's crust. Deep earthquakes can occur up to 700 km.

Divergent Movement

Movement where two tectonic plates move away from each other, typically found at mid-ocean ridges.

Asthenosphere

The viscous layer beneath the lithosphere, allowing tectonic plates to move.

Continental Drift

The hypothesis, proposed by Alfred Wegener, that continents move across the Earth's surface over long periods.

Mid-Atlantic Ridge

A mid-ocean ridge that forms a divergent boundary between the Eurasian and North American plates.

Seafloor Spreading

The process by which new oceanic crust forms along mid-ocean ridges and older crust moves away from the ridge.