Stress

BD: A force that acts on rocks to change its shape or volume.

MD: Pressure that changes that shape or volume.

Tension

BD: Stress that stretches rock so that it becomes thinner in the middle.

MD: Pressure that pulls a rock from both sides.

Compression

BD: Stress that squeezes rock until it folds or break.

MD: Pressure breaks or folds a rock.

Shearing

BD: Stress that pushes masses of rock in opposite directions, in a sideways movement.

MD: Pressure that moves rocks opposite direction.

Normal Fault

BD:A type of fault where the hanging wall slides downward; cuased by tension in the crust.

MD: A fault cuased by tension in the crut.

Hanging Wall

BD: The block of rock that forms the upper half of a fault.

MD: A block of rock that is the upper half of a fault.

Footwall

BD:The block of rock that forms the lower half of a fault.

MD:A block of rock that is on the bottom of a fault.

Reverse Fault

BD:A type of fault where the hanging wall slides upward; caused by compression in the crust.

MD: A fault where the hanging wall is going up.

Strike-slip Fault

BD:A type of fault in which rocks on either side move past each other sideways with little up or down motion.

MD: A fault in which the plates move past each other.

Anticline

BD:An upward fold in rock formed by compression of Earth’s crust.

MD: The upper fold of on the Earth's crust.

Syncline

BD:A downward fold in rock formed by compression in Earth’s crust.

MD: The downward fold of on the Earth's crust.

Plateau

BD:A large area of flat land elevated high above sea level.

MD: A falt land above sea level.

Earthquakes

BD:The shaking that results from the movement of rock beneath Earth’s surface.

MD: Shaking of the Earth because of rock under Earth's surface.

Epicenter

BD:The point on Earth’s surface directly above an earthquake’s focus.

MD: The center of the earthquake

Focus

BD:The point beneath Earth’s surface where rock breaks under stress and causes an earthquake.

MD: The point where the rock breaks.

P-waves

BD:A type of seismic wave that compresses and expands the ground.

MD:A seismic wave that that spreads the ground.

S-waves

BD:A type of seismic wave that moves the ground up and down or side to side.

MD: A seismic that make the ground go up and down or side to side.

Surface Waves

BD:Water waves and travel along the Earth's surface. They travel slower than L waves.

MD: Waves that travel along the Earth's surface.

Magnitude

BD:The measurement of an earthquake’s strength based on seismic waves and movement along faults.

MD: The measurement of earthquakes' strength based on seismic waves.

Intensity

BD:magnitude, as of energy or a force per unit of area, volume, time, etc.

MD: The force per unit of area etc.

Seismograph

BD:A device that records ground movements caused by seismic waves as they move through Earth.

MD: A device that records earthquake movements.

Seismogram

BD:The record of an earthquake’s seismic waves produced by a seismograph.

MD:The sheet that has the seismic waves on it.

Friction

BD:The force that opposes the motion of one surface as it moves across another surface.

MD: The force that blocks the motion of one surface as it goes into another surface.

Aftershock

BD: A earthquake that occurs after a larger earthquake in the same area.

MD: A small earthquake after the main one.

Tsunami

BD:A large wave produced by an earthquake on the ocean floor.

MD: A large wave made by an earthquake.

Seicmic Waves

BD: Vibrations that travel through Earth carrying the energy released during an earthquake.

MD: Vibrations released during an earthquake.