Science Words

Front 1

Fault

Back 1

Surfaces along which rocks break and move; rocks on either side of a fault move in different directions relative to the fault surface.

Front 2

Earthquake

Back 2

The movement of the ground, caused by waves of energy released as rocks move along faults.

Front 3

Normal Fault

Back 3

A pull apart "tension" fracture in rocks, where rocks that are above the fault surface drop downward in relation to rocks that are below the fault surface like this:

Front 4

Reverse Fault

Back 4

A compression fracture in rocks, where rocks that are above the fault surface are forced up over rocks that are below the fault surface like this:

Front 5

Strike - Slip Fault

Back 5

A break in rocks due to shearing forces, where rocks on either side of the fault move past each other without much upward or downward movement.

Front 6

Seismic Wave

Back 6

In an earthquake, the energy waves that move outward from the earthquake focus and make the ground quake.

Front 7

Focus

Back 7

The point in Earth's interior where earthquake energy is released.

Front 8

Primary Wave

Back 8

Waves of energy, released during an earthquake, that travels through Earth by causing particles in rocks to compress and stretch apart in the direction of the wave.

Front 9

Secondary Waves

Back 9

Waves of energy, released during an earthquake, that travel through Earth by causing particles in rocks to move at right angles to the direction of the wave.

Front 10

Epicenter

Back 10

The point on Earth's surface directly above an earthquake's focus.

Front 11

Surface Wave

Back 11

Wave of energy, released during an earthquake, that reach Earth's surface and travel outward from the epicenter in all directions; travel through Earth by giving rock particles an elliptical and side to side motion.

Front 12

Inner Core

Back 12

A dense, solid center of Earth, formed mostly of iron and nickel.

Front 13

Outer Core

Back 13

The liquid layer of Earth's core that surrounds the solid Inner Core and is comprised of iron and nickel.

Front 14

Mantle

Back 14

The thickest layer of Earth; that lies between the Outer Core and the Crust and is described as plastic like; formed mostly of silicon, oxygen, magnesium, and iron.

Front 15

Crust

Back 15

The outermost layer of Earth, varying in thickness from more than 60 KM to less than 5 KM.

Front 16

Moho Discontinuity

Back 16

The boundary between Earth's crust and the mantle; the seismic waves travel faster below the Moho and slower above it.

Front 17

Seismologist

Back 17

A scientist who studies earthquakes and seismic waves.

Front 18

Seismograph

Back 18

An instrument used by Seismologists to record Primary, Secondary and Surface waves from earthquakes.

Front 19

Magnitude

Back 19

In earthquakes studies, a measure of the energy released by an earthquake; the Richter Scale is used to describe earthquake magnitude.

Front 20

Tsunami

Back 20

An ocean wave in (seismic sea wave) that begins over an earthquake focus and can reach 30 M high.

Front 21

Volcano

Back 21

A vent in Earth's surface that often forms a mountain built of lava and volcanic ash, which erupts and builds up.

Front 22

Vent

Back 22

In volcanic regions, an opening in Earth's surface through which can flow lava, ash, cinders, smoke, and steam.

Front 23

Crater

Back 23

A steep-walled depression at the top of a volcanic vent.

Front 24

Pacific Ring of Fire

Back 24

The area around the Pacific Plate where volcanoes and earthquakes are common due to tectonic movement.

Front 25

Hot Spot

Back 25

Areas in Earth's mantle that are hotter than the neighboring areas forming melted rock that rises toward the crust.

Front 26

Geothermal Energy

Back 26

Thermal energy from magma bodies inside Earth that can be used to produce electricity with very little environmental pollution.

Front 27

Hot Dry Rock (HDR)

Back 27

A new technology in which heat from Earth's internal hot dry rock material is used to generate energy.

Front 28

Shield Volcano

Back 28

A broad volcano with gently slopping sides, built by quiet eruptions of fluid basaltic lava, which spreads out in flat layers; example: the Hawaiian Islands.

Front 29

Tephra

Back 29

Lava that is blasted into the air by violent volcanic eruptions and solidifies as it falls to the ground as ash, cinders, and volcanic bombs.

Front 30

Cinder Cone

Back 30

A type of volcano in which tephra (cinders) piles up into a steep-sided cone.

Front 31

Composite Volcano

Back 31

A type of volcano built of silicarich lava and tephra layers accumulated from repeating alternating cycles of tephra eruptions and lava eruptions.

Front 32

Batholith

Back 32

The largest intrusive igneous rock bodies that form when magma cools and solidifies under ground and stops rising to the surface.

Front 33

Sill

Back 33

An intrusive igneous rock body formed when magma is squeezed into a horizontal crack and solidifies under ground.

Front 34

Volcanic Neck

Back 34

Solid igneous core of event that remains after the outer layers of lave and tephra have been eroded away from an extinct volcano.

Front 35

Caldera

Back 35

A large opening formed at the top of a volcano when a crater collapses into the vent following an eruption.

Front 36

Continental Drift

Back 36

A hypothesis

Front 37

Continental Drift

Back 37

A hypothesis proposed by Alfred Wegener, which states that continents have moved horizontally around the globe, over time, to reach their current locations.

Front 38

Pangaea

Back 38

The name Alfred Wegener gave to large land mass, made up of all continents, that he believed existed before it broke apart to form the present continents.

Front 39

Plate Tectonics

Back 39

The theory that Earth's crust and upper mantle (Lithosphere) are broken into sections, called plates, that slowly move around on the mantle.

Front 40

Plate

Back 40

In plate tectonics, a section of Earth's Lithosphere (crust and upper mantle) that moves around on the mantle.

Front 41

Lithosphere

Back 41

The rigid, outermost layer of Earth, about 100 KM thick, composed of the crust and part of the mantle.

Front 42

Asthenosphere

Back 42

The plasticlike layer below the Lithosphere in Earth's mantle.

Front 43

Divergent Boundary

Back 43

In Plate Tectonics, the boundary between two plates that are diverging, or moving away from each other.

Front 44

Convergent Boundary

Back 44

In Plate Tectonics, the boundary between two plates that are converging, or moving toward each other.

Front 45

Subduction Zone

Back 45

In Plate Tectonics, the area where an ocean-floor plate collides with a continental plate, and the denser ocean plate sinks under the less dense continental plate.

Front 46

Transform Fault

Back 46

The layer of Earth's atmosphere closest to the ground; contains clouds, smog, weather and 75% of the atmospheric gases.

Front 47

Convention Current

Back 47

The driving force of Plate Tectonics in which hot, plasticlike material from the mantel rises to the Lithosphere, moves horizontally, cools, and sinks back to the mantle.