Earthquakes & Volcanoes Study Guide

Earthquakes & Volcanoes Study Guide

• Stress: The force that acts on a rock to change its shape or volume.
• Tension: Pulling the Earth's crust, getting thinner in the middle.
• Compression: Squeezing rock until it folds or breaks.
• Shearing: Force pushes a mass of rock in two opposite directions.
• Fault: A fracture in Earth's crust.
• Earthquake: Shaking and trembling from the movement of Earth's crust plate boundaries.
• Seismic Waves: Energy carried from an earthquake's focus.
• Magnitude: Measurement of an earthquake's strength (a single number based on size).
• Tsunami: A giant wave caused by an underwater earthquake.
• Viscosity: How thick a liquid is and how easily it pours.
• Aa Lava: Slow-moving, cooler lava that dries rough.
• Pahoehoe Lava: Fast-moving, hotter lava that dries smooth or ropey.
• Pyroclastic Flow: Hot, dense mixture of ash, gas, and rock fragments from a volcano.
• Magma: Molten material in the Earth.
• Lava: Molten material on the Earth's surface.
• Volcano: A weak spot in the crust where magma comes to the surface.
• Hot Spot: An area where lava frequently erupts at the surface, independent of plate boundaries.
• Focus (Earthquake): Point in the crust where an earthquake begins.
• Epicenter (Earthquake): Point on the Earth's surface directly above the focus.
• Seismograph: Instrument used to record ground movements caused by seismic waves.

Volcano Types

• Shield Volcano: Quiet eruptions, AA and Pahoehoe lava.
• Cinder Cone Volcano: Quiet eruptions, AA lava.
• Composite Volcano: Explosive eruptions, AA lava.

Seismic Waves

• Primary (P-waves): Compress and expand, travel through solids and liquids.
• Secondary (S-waves): Vibrate side-to-side and up-and-down, travel only through solids.
• Surface Waves: Travel along the surface, cause the most damage.

This study guide covers essential concepts related to earthquakes and volcanoes. It includes definitions and explanations of key terms such as stress, tension, seismic waves, and types of lava. Ideal for students preparing for exams in Earth Science.