Unit 4B - The Earth

Question 1

Crust

Answer 1

The thin and solid outermost layer of the Earth above the mantle.

Question 2

Divergent boundary

Answer 2

A tectonic plate boundary where two plates move away from each other.

Question 3

Earthquake

Answer 3

Sudden and violent shaking of the ground, sometimes causing great destruction, as a result of movements within the earth’s crust.

Question 4

Erosion

Answer 4

The process by which wind, water, ice, or gravity transports soil and sediment from one location to another.

Question 5

Fault

Answer 5

A crack in the earth’s crust where earthquakes occur.

Question 6

Hot spots

Answer 6

Places in the middle of tectonic plates where molten material from the mantle reaches the surface.

Question 7

Leaching

Answer 7

Process in which various chemicals in upper layers of soil are dissolved and carried to lower layers.

Question 8

Lithosphere

Answer 8

The rigid outer layer of the earth that floats on the asthenosphere.

Question 9

Loam

Answer 9

Soil with an equal mixture of sand, silt, and clay that is ideal for agriculture.

Question 10

Mantle

Answer 10

The hot, mostly solid, layer of the Earth between the core and crust.

Question 11

Parent material

Answer 11

The base geological material in a particular location from which the inorganic parts of soil are derived.

Question 12

Permeability

Answer 12

The ability of a rock or sediment to let fluids flow through its open spaces.

Question 13

pH

Answer 13

A scale from 0-14 that is a measure of the hydrogen ion concentration in a substance, with lower values being acidic and higher values being alkaline or basic.

Question 14

Plate boundary

Answer 14

The region where two tectonic plates meet.

Question 15

Plate tectonics

Answer 15

The theory that pieces of Earth’s lithosphere are in constant motion, driven by convection currents in the mantle.

Question 16

Porosity

Answer 16

A measure of how much of a rock is open space, which allows it to hold water.

Question 17

Sand

Answer 17

The coarsest size of soil particles.

Question 18

Seafloor spreading

Answer 18

The formation of new ocean crust as a result of magma pushing upward and outward from Earth’s mantle to the surface.

Question 19

Silt

Answer 19

The intermediate size of soil particles.

Question 20

Soil

Answer 20

A mixture of inorganic rock fragments, organic material, living organisms, water, and gases that can support the growth of plants.

Question 21

Soil horizons

Answer 21

Horizontal layers of soil with differing characteristics such as color and texture.

Question 22

Soil profile

Answer 22

A vertical section of soil that shows all of the horizons that make up the soil in a particular place.

Question 23

Soil texture

Answer 23

Relative amounts of the different types and sizes of mineral particles in a sample of soil.

Question 24

Stratification

Answer 24

The process in which sedimentary rocks are arranged in layers of deposited minerals.

Question 25

Tectonic plates

Answer 25

Sections of the Earth's lithosphere that move due to convection currents in the asthenosphere below.

Question 26

Transform boundary

Answer 26

A tectonic plate boundary where two plates move past each other in opposite directions.

Question 27

Volcano

Answer 27

A fissure in the earth's crust that allows magma as well as gases to reach the surface.

Question 28

Weatering

Answer 28

The breaking down by wind, water, or chemical means, of rocks on the Earth's surface.

Question 29

Humus

Answer 29

Rich, dark organic material formed by decay of vegetable matter, essential to soil's fertility

Question 30

Convergent plate boundary

Answer 30

A tectonic plate boundary where two plates collide, come together, or crash into each other.

Question 31

Subduction zone

Answer 31

The region where oceanic plates sink down into the asthenosphere.

Question 32

Clay

Answer 32

the finest soil, made up of particles that are less than 0.002 mm in diameter.

Question 33

Ore

Answer 33

a rock that contains a large enough concentration of a mineral making it profitable to mine

Question 34

Tsunami

Answer 34

A huge destructive wave (especially one caused by an earthquake)

Question 35

Mountaintop removal

Answer 35

A mining technique in which the entire top of a mountain is removed with explosives

Question 36

Subsurface mining

Answer 36

The extraction of mineral and energy resources from deep underground deposits.

Question 37

Strip mining

Answer 37

involves the removal of the Earth's surface all the way down to the level of the mineral seam.

Question 38

Placer mining

Answer 38

the process of looking for minerals, metals, and precious stones in river sediments

Question 39

Desertification

Answer 39

Degradation of land, especially in semiarid areas, primarily because of human actions like excessive crop planting, animal grazing, and tree cutting.

Question 40

Soil sanitization

Answer 40

in arid regions, irrigation water evaporates, leaving salts behind

Question 41

Tailings

Answer 41

Rock and other waste materials removed as impurities when waste mineral material is separated from the metal in an ore.

Question 42

Slag

Answer 42

stony waste matter separated from metals during the smelting or refining of ore.

Question 43

Soil compaction

Answer 43

When soil is pressed down tightly resulting in the removal of air pockets; therefore not allowing water to penetrate or plants to grow.

Question 44

Soil nutrients

Answer 44

an inorganic ion that a plant requires for normal growth and reproduction and that it acquires from the soil

Question 45

Overburden

Answer 45

Layer of soil and rock overlying a mineral deposit. Surface mining removes this layer.

Question 46

Remediation

Answer 46

return a contaminated area to its original state

Question 47

Mitigation

Answer 47

The policy of constructing or creating man-made habitats, such as wetlands, to replace those lost to development