Academic Earth/Space Science : Midterm Exam Study Guide

Timlin, Block 3

Oxygen, silicon, aluminum, calcium, iron, magnesium, sodium, and potassium.

What are the major elements of Earth’s crust?

Relation between elements and minerals

elements make up minerals

Isotope

an atom that has the same number of protons but a different number of neutrons.

compound

consists of two or more elements that are chemically combined in specific proportions

covalent bonds

form when atoms share electrons

metallic bonds

form when metal ions share electrons

ionic bonding

forms between negative and positive ions

Characteristics of a mineral

crystalline structure, chemical compound, solid, naturally occurring, and inorganic

silicon-oxygen tetrahedron

the building blocks of all silicates

What is a mineral’s streak?

the color of the powder of a mineral

Which mineral property is least useful?

color

Why would a mineral cleave?

In the atomic structure of a mineral, some bonds are weaker than others. These weak bonds are places where a mineral will break when it’s stressed.

density formula

d=m/v

How are rocks classified?

By how they form

Rock Cycle

slow cooling

underground causes large grains

fast cooling

above ground causes smaller grains

What are the various changes that occur during metamorphism?

new minerals grow with different sizes, shapes, and orientations than those of other minerals.

Contact metamorphism

intruding magma causes localized areas of elevated temperature that alter rock

regional metamorphism

occurs over large areas of Earth’s crust, usually during mountain building, and is associated with very high temperatures and pressure

placer deposits

minerals that fall into the cracks of creek beds

Advantages of solar energy

free, clean, renewable source

Nuclear fusion

a uranium atom is split in a controlled reaction, which creates energy, which generates heat, which boils water, which creates steam that spins a turbine

How does hydroelectric power create energy?

water spins a turbine

point source pollution

pollution from a known and specific location, such as factory pipes

non-point source pollution

pollution that doesn’t have a specific point or origin

When were the most anti-pollution laws passed?

1970s

What is the most important law for air pollution?

Clean Air Act

mechanical weathering

occurs when physical forces break rock into smaller and smaller pieces without changing the rock’s mineral composition

frost wedging

the mechanical breakup of rock caused by the expansion of freezing water in cracks and crevices

What type of weathering is most effective in mid-latitudes?

frost wedging

What affects the rate of weathering?

rock characteristics and climate

In which climate is weathering the most effective?

hot, wet climate

what are the various components of soil

mineral matter, or broken-down rock; humus, which is the decayed remains of organisms; water; and air.

What determines a soil’s texture?

grain size, sand (large), silt, and clay (small)

What is the main source of organic matter in soil?

plants

A horizon

loose and partly decayed mineral matter)

B horizon

clay transported from above

C horizon

partially weathered parent material

pedalfer

usually form in temperate areas that receive more than 63 cm of rain every year. This soil is present in much of the forested areas in the eastern area of the states. The B horizon in this type of soil usually contains a large amount of iron oxide, making it a red-orange color.

pedocal

found in the western US in areas that have grasses and bush vegetation. Since chemical weathering is slower in drier climates, they usually contain less clay than pedalfers. They contain calcite, or calcium carbonate, and are typically a light-gray brown.

laterite

form in hot, wet, tropical areas. Chemical weathering is intense. The large quantity of water that passes through these soils removes most of the calcite and silica. Iron oxide and aluminum are left behind and the iron oxide gives it it’s distinct red color.

soil erosion rates today vs the past

The soil erosion rates are faster today because of human and biological removal of plant life and vegetation

How do humans impact soil erosion?

Human activities that remove natural vegetation, such as farming, logging, and construction, have greatly accelerated erosion

What are the various trigger of mass movements?

saturation of surface materials with water, over steepening of slopes, removal of vegetation, and earthquakes.

over-steepened slope

a steepened slope that exceeds over 40 degrees

What is the general seed of the various mass movements?

creep is the slowest, mudslide is the fastest

fault

a fracture in the earth where movement has occurred

focus

the point where an earthquake starts

foreshock

a small earthquake that can happen days or years before an earthquake

aftershocks

after an earthquake and can happen for weeks or months after the initial quake

P waves

the fastest, can travel through solids, liquids, and gasses

S waves

come second, and can only travel through solids

surface waves

come last and are the most destructive

What are the various scales used to measure earthquakes?

richter scale, seismograph, modified mercalli scale, and momentum magnitude

seismograph

instrument that records earthquake waves

seismogram

comes from the seismograph

How does the Richter scale measure earthquakes?

based on the height of the largest seismic wave based on a seismograph

tsunami

triggered by an earthquake, occurs where a slab of the ocean floor is displaced vertically along a fault

Layers of the Earth defined by physical properties

Lithosphere, Asthenosphere, Lower Mantle, Inner core, Outer Core

Layer of the Earth defined by Composition

Crust, Mantle, Core

Core

below mantle and composed of iron-nickel alloy

mantle

has the igneous peridodite

crust

thin, rocky layer that is mostly made out of granite

lithosphere

crust and uppermost mantle

asthenosphere

below the lithosphere and has the upper mantle

lower mantle

consists of rocks that are very hot and capable of gradual flow

outer core

liquid layer surrounding the inner core

inner core

behaves like a solid due to extreme pressures