The focus, or hypocenter, is the point inside the Earth where the earthquake begins, while the epicenter is the point on the surface directly above it.

The Richter scale measures the seismic energy released by an earthquake, whereas the Mercalli scale measures intensity based on observed damage.

Tsunamis are large sea waves caused by the displacement of water, most commonly triggered by undersea earthquakes, volcanic eruptions, or landslides.

Shield volcanoes have a broad, low profile and are built by the accumulation of fluid basaltic lava flows.

The Ring of Fire is a path along the Pacific Ocean characterized by active volcanoes and frequent seismic activity due to plate tectonics.

Primary waves (P-waves) are longitudinal waves and are the fastest seismic waves, meaning they reach recording stations before S-waves.

A fumarole is an opening in or near a volcano, through which hot sulfurous gases and steam are emitted.

The Modified Mercalli Intensity Scale measures the intensity of an earthquake based on the observed effects and damage on the Earth's surface.

Surface waves (Love and Rayleigh waves) travel along the Earth's surface and cause the most structural damage during an earthquake.

Convergent boundaries occur where plates move toward each other, often resulting in deep-sea trenches, volcanic arcs, and mountain ranges.

Magma is molten rock located beneath the surface, while lava is the term used for molten rock that has reached the Earth's surface.

Soil liquefaction happens when intense shaking causes water-saturated granular soil to lose its mechanical strength and behave like a fluid.

Composite volcanoes, or stratovolcanoes, are built up by many layers of hardened lava, tephra, pumice, and ash.

Deep-ocean Assessment and Reporting of Tsunamis (DART) buoys measure sea-level height changes at the ocean floor to provide early warning of tsunamis.

The shadow zone is an area on Earth's surface where seismographs cannot detect direct earthquake waves due to refraction at the Earth's core-mantle boundary.

A pyroclastic flow is a highly destructive, fast-moving avalanche of hot gas, ash, and rock fragments from an erupting volcano.

Convection currents in the semi-solid mantle drive the motion of the rigid tectonic plates floating above it.

As a tsunami moves into shallower coastal water, friction slows the wave (decreasing velocity), causing the water to pile up and height to increase.

The Moment Magnitude Scale is a more accurate measure because it uses the physical properties of the fault, including the size of the rupture area and the amount of slip, to calculate total energy.