module 2: making mountains and earthquakes vocab

What is the main source of Earth’s internal heat?

Radioactive decay of elements (uranium, thorium, potassium), plus leftover formation heat and core processes.

What are the three ways heat moves?

Radiation (electromagnetic waves), conduction (atom‑to‑atom collisions), convection (movement of heated material).

What is convection in geology?

Hot, less‑dense rocks rise, cool, and sink, creating currents that drive plate tectonics.

What is the lithosphere?

Rigid outer layer of Earth (crust + upper mantle) that breaks rather than flows.

What is the asthenosphere?

Softer mantle layer beneath the lithosphere that flows and enables plate movement.

What is plate tectonics?

Study of lithospheric plates and their movements/interactions on Earth’s convecting mantle.

How was Death Valley formed?

Pull‑apart faults dropped blocks of crust, widening the Basin and Range region.

What is a pull‑apart fault?

Fault system where angled breaks cause blocks to drop and the region to widen.

What is sea‑floor spreading?

Process where new ocean crust forms at mid‑ocean ridges and moves outward as plates diverge.

What are black smokers?

Hydrothermal vents at mid‑ocean ridges where mineral‑rich water emerges, forming ore deposits and unique ecosystems.

What is the Yellowstone Caldera?

Collapse depression formed by three massive eruptions (1.8, 1.2, 0.6 million years ago).

What is a geyser?

Eruption of hot water/steam under pressure, requiring heat, water, and sealed plumbing.

What is Elastic Rebound Theory?

Rocks bend and store energy until faults release, snapping back rapidly to cause earthquakes.

What are P‑waves?

Fast compressional seismic waves that travel through solids, liquids, and gases.

What are S‑waves?

Slower shear seismic waves that travel only through solids, not liquids or gases.

What is the S‑wave shadow zone?

Region opposite a quake where S‑waves are absent, proving Earth’s outer core is liquid.

Where do most earthquakes occur?

At plate boundaries (extension, compression, shear), but also at weak spots in continents.

What is a failed rift?

A fracture that did not fully develop into an ocean basin, often a weak zone where quakes occur.

What is the Richter Scale?

Logarithmic measure of earthquake magnitude; each +1 = 10× motion, ~30× energy.

How does earthquake frequency relate to magnitude?

Each +1 magnitude → ~10× less frequent, but ~30× more energy released.

What is a seismic gap?

Quiet section of a fault where stress may be building toward a large quake.

What are premonitory events?

Possible warning signs (rock cracking, groundwater shifts, animal behavior), but unreliable for prediction.