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the innermost layer of Earth; made mostly of the metals iron and nickel; consists of two parts - a liquid outer core and a solid inner core
the name of the single landmass that broke apart 200 million years ago and gave rise to today's continents
an undersea mountain chain where new ocean floor is produced; a divergent plate boundary
the process by which oceanic crust sinks beneath a deep-ocean trench and back into the mantle at a convergent plate boundary
the theory that pieces of Earth's lithosphere are in constant motion, driven by convection currents in the mantle
the movement of a fluid, caused by differences in temperature, that transfers heat from one part of the fluid to another
a type of seismic wave that moves the ground up and down or side to side; these waves arrive after P waves
a scale that rates earthquakes according to their intensity and how much damage they cause at a particular place
the measurement of an earthquake's strength based on seismic waves and movement along faults
a scale that rates seismic waves as measured by a particular type of mechanical seismograph
moment magnitude scale
a scale that rates earthquakes by estimating the total energy released by an earthquake
any characteristic of a substance that can be observed or measured without changing the composition of the substance
the expulsion of ash, cinders, bombs, and gases during an explosive volcanic eruption
a steep, cone-shaped hill or small mountain made of volcanic ash, cinders, and bombs piled up around a volcano's opening
a tall, cone-shaped mountain in which layers of lava alternate with layers of ash and other volcanic materials
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