science test study

Geosphere

The solid part of the Earth consisting of all rock, soil, and loose rocks on the surface.

Seismograph

An instrument that measures and records seismic waves generated by earthquakes.

Primary Wave (P Wave)

The fastest seismic wave that moves the ground back and forth in a longitudinal compressional motion.

Secondary Wave (S Wave)

A seismic wave that arrives second and shakes the ground side-to-side in a transverse motion perpendicular to the direction of travel.

Lithosphere

The rigid, brittle outermost layer of Earth composed of the crust and upper mantle, broken into tectonic plates.

Asthenosphere

A warm, semi-fluid layer of the upper mantle below the lithosphere that flows slowly and drives plate movement.

Convection

Heat-driven movement within a fluid where hotter, less dense material rises and cooler, denser material sinks.

Crust

The outermost and thinnest solid layer of Earth, categorized into continental and oceanic types.

Outer Core

The liquid layer of iron and nickel that creates Earth's magnetic field and blocks S waves.

Inner Core

The solid, extremely hot center of Earth made of iron and nickel, kept solid by intense pressure.

Ring of Fire

A Pacific Ocean region with active tectonic boundaries that experiences high volcanic and earthquake activity.

Zhang Heng

The inventor who created the first seismograph, known as the Houfeng Didong Yi, in 132 A.D.

Richter Scale Ground Motion Jump

Each whole number increase on the scale represents a $10\text{ times}$ increase in measured ground motion.

Richter Scale Energy Jump

Each whole number increase on the scale represents approximately a $32\text{ times}$ increase in released energy.