Global Distribution and Causes of Earthquakes, Volcanic Eruptions, and Tsunamis

Vocabulary flashcards covering the global distribution and specific geological causes of earthquakes, volcanoes, and tsunamis based on the lecture transcript.

Earthquake Cause

The sudden release of energy resulting from stress accumulation along faults or plate boundaries.

Convergent Boundaries (Earthquakes)

Plate boundaries where plates collide, causing intense pressure and deep-focus earthquakes (e.g., the Pacific Ring of Fire).

Divergent Boundaries (Earthquakes)

Plate boundaries where plates pull apart, producing shallow-focus earthquakes (e.g., the San Andreas Fault as listed in the notes).

Transform Boundaries (Earthquakes)

Plate boundaries where plates slide past each other, resulting in lateral displacement and shallow to intermediate earthquakes (e.g., the Mid-Atlantic Ridge as listed in the notes).

Intra-plate Earthquakes

Earthquakes that occur away from plate boundaries, which happen less frequently than boundary earthquakes.

Volcanic Eruption Cause

The eruption of magma at the surface after it is generated in the mantle or lower crust and rises.

Convergent Boundary Volcanism

Volcanic formation where an oceanic plate subducts beneath another plate, melts due to increasing temperature and pressure, and produces magma that erupts at the surface.

Divergent Boundary Volcanism

Volcanic activity where magma rises from the mantle as plates move apart, creating new crust (e.g., the Mid-Atlantic Ridge).

Hotspot Volcanoes

Intra-plate volcanoes that form independently of plate boundaries due to mantle plumes, such as Hawaii and Iceland.

Pacific Ring of Fire

The most active global zone for earthquakes and volcanoes, characterized by numerous subduction zones.

Tsunamis (Primary Cause)

Undersea earthquakes at subduction zones that cause sudden vertical displacement of the sea floor and displace large volumes of water.

Tsunami Wave Behavior

Long-wavelength waves that travel at high speed across ocean basins, but slow down and increase in height upon reaching shallow coastal areas.

Secondary Causes of Tsunamis

Less common triggering events for tsunamis, including volcanic eruptions (such as the collapse of volcanic islands), underwater landslides, and meteorite impacts.

Himalayan Region Seismicity

High seismic activity resulting from continental collision.