VIRTUAL EARTHQUAKE http://www.sciencecourseware.org/virtualearthquake/php/DoRichter3.php

http://www.slideshare.net/cfoltz/earth-science-41-inside-the-earth

http://www. slideshare http://www.slideshare.net/allsaintsscience/7th-grade-ch-1-sec-1-earths-interior

DIVERGENT BOUNDARY Boundary between two plates that are moving apart.

CONVECTION CURRENT A current in Earth’s mantle that transfers heat in Earth’s interior and is the driving force for plate tectonics.

ASTHENOSPHERE Plastic like layer of Earth on which the tectonic plates float and move around.

LITHOSPHERE The rigid layer of Earth about 100 km thick, made of the crust and a part of the upper mantle.

CONVERGENT BOUNDARY Boundary where two plates come together. They can form mountain ranges, volcanoes and tranches.

SEAFLOOR SPREADING When oceanic plates separate and form mid-ocean ridges. Rising magma cools and forms new oceanic crust.

TRANSFORM BOUNDARY Formed where two plates slide past each other. They move in opposite directions.

SEISMIC WAVES Waves generated by an earthquake that travel through Earth.

MAGNITUDE A measure of the energy that is released from an earthquake. Richter magnitude scale

TSUNAMI Ocean waves caused by earthquakes. Seismic sea waves.

VENT An opening in Earth’s surface where magma is released.

EPICENTER The point on the Earth’s surface directly above the focus of the earthquake.

FOCUS The point where the energy release of the earthquake first occurs. Located about 65 km beneath the surface of the Earth.

SEISMOGRAPH An instrument that measures seismic waves from earthquakes and volcanic eruptions. They register the waves and record the time of the wave arriving at the station.

PRIMARY WAVES Particles in rock stretch and compress as energy moves through it. The first wave that leaves the focus of the earthquake.

SECONDARY WAVES Particles in rock move in a backward, rolling motion and a side to side, swaying motion. Picture a wave moving through a jump rope.