Earth Science (UPCAT reviewer)

Minerals

naturally occurring inorganic solid material that possesses an orderly crystalline structure and can be represented by a chemical formula

Properties of minerals

crystal shape (habit), luster, color, streak, tenacity, hardness, cleavage, fracture, density

Most common element composition of minerals

oxygen (O), silicion (Si), aluminum (Al), iron (Fe), calcium (Ca), sodium (Na), potassium (K), magnesium (Mg)

Silicates

most common group of minerals, contain -SO2 groups that have a tetrahedral crystal shape

Carbonates

minerals that contain carbonate ions that exhibit effervescence (foaming reaction to acids)

Ore

naturally occurring concentration of mineral deposits that can be extracted economically

Rocks

consolidated mixtures of minerals

Igneous Rocks

formed from cooling magma that solidified through crystallization

Igneous Rocks

classified by texture and mineral composition

Igneous Rocks

size of solidified crystals dependent on rate of cooling of magma

Intrusive Igneous Rocks

large crystals formed from slow cooling of magma below Earth's surface (e.g. Granite)

Extrusive Igneous Rocks

small crystals formed from quick cooling of magma at the earth's surface (e.g. Basalt)

Sedimentary Rocks

formed from the lithification (compaction) of sediment

Detrital Sedimentary Rocks

originate as solid particles derived from weathering and are transported (e.g., shale, sandstone)

Chemical Sedimentary Rocks

originate from soluble materials produced by chemical weathering (e.g., limestone, chert)

Metamorphic Rocks

formed from previous rocks that were subjected to extreme pressure and heat

Metamorphism

rocks are subjected to extreme heat and pressure

Effects of Metamorphism

increased density, recrystallization (formation of larger crystals), reorientation of mineral gains (foliation), formation of new minerals

Continental Drift

hypothesis proposed by alfred wegener of the breaking apart of a supercontinent (pangaea) into smaller continents, then drifting into their current positions; no scientific explanation for the drifting mechanism was proposed

Plate Tectonics

provides the mechanism for the continental drift hypothesis; proposes that the earth is divided into a solid and liquid layer

Lithosphere

outer solid layer of the earth, divided into segments called plates

Plates

move uniformly and are deformed across their boundaries

Asthenosphere

weaker inner liquid layer of the eartg

Earthquake

rapid vibration of earth due to the release of energy from rocks that were subjected to extreme pressure; happens in faults, which are associated with plate boundaries

Divergent Boundary

plates move apart from each other

Divergent Boundary

results in upwelling of magma

Divergent Boundary

associated with seafloor spreading (e.g., mid-atlantic ridge)

Divergent Boundary

also associated with continental rifts

Transform Boundary

plates grind against each other

Transform Boundary

no lithosphere is created nor destroyed

Transform Boundary

can be sites for earthquakes

Convergent Boundary

plates move towards each other

Convergent Boundary

results in subduction of oceanic lithosphere

Convergent Boundary

associated with the formation of volcanic arcs

Convergent Boundary

also associated with the formation of mountain ranges (e.g., himalayas)

Evidence of Plate Tectonics

jigsaw fit of the coastlines of south america and africa, similar fossils found on continents separated by water, similar fragments of mountain belts found on continental separated by water, similar glacial deposits found on antartica, africa, south america, india, and australia and sediments closer to plate boundaries have ages that are different from those of farther sediments

Island Hotspots

moving lithosphere creates new several islands even if there is only one magma source (e.g., hawaii)

Paleomagnetism

evidences of the changing location of the magnetic north pole; different paths of the change of the magnetic north pole imply that the plates move

Composition of a volcanic eruption

lava flow, gases, pyroclastic material

Types of Pyroclastic Material by size (smallest to largest)

ash/dust -> lapilli/cinder -> block -> bomb

Composite Volcano

symmetrical cones with structures of interbedded lava and pyroclastic material

Cinder Cone Volcano

have steep slopes composed of pyroclastic material

Shield Volcano

broad, doomed volcanoes composed of basaltic lava

Weathering

external process of the lithosphere / disintegration and decomposition of rock near the surface

Mass-wasting

external process of the lithosphere / transfer of rock material downslope incorporation and transportation of material by a mobile agent

Movement of tectonic plates

internal process of the lithosphere / can result in earthquakes and the formation of volcanoes, mountains, rift valleys, trenches, mid-oceanic ridges, and islands

The Hydrosphere

continental shelf, continental slope, continental rise, deep-ocean basin, deep-ocean trenches, abyssal plains, seamounts and guyots, oceanic plateaus, atolls, oceanic ridge, ocean currents, coriolis effect, upwelling, shore, beach, tides, hydrologic cycle, drainage basin, groundwater, spring, geyser

Continental Shelf

underwater landmass that extends from the coastline to the shelf break, then towards the deep-ocean basin

Continental Slope

steep sloping from the continental shelf into deep ocean floor

Continental Rise

found where trenches do not exist, less steep and has a gradual incline after the continental slope

Deep-ocean Basin

lies between continental margin and oceanic ridge system

Deep-ocean Trenches

crustal plates descending into mantle

Abyssal Plains

level area, contains thick accumulations of sediment

Seamounts and Guyouts

isolated volcanic peaks

Oceanic Plateaus

accumulations of basaltic lava flows

Atolls

reef-building of corals and other organisms on the flanks of sinking volcano islands

Oceanic Ridge

found in the middle of ocean basins, site of divergent plate boundaries where seafloor spreading occurs

Ocean Currrents

masses of ocean water that flow from one place to another, follow a circular movement across the ocean (gyres)

Coriolis Effect

movement of particles opposite that of the rotation of the earth, causes gyres in the northern hemisphere to turn clockwise and gyres in the southern hemisphere to turn counterclockwise

Upwelling

upward movement of cold water from deeper layers

Shore

area extending between the lowest tide level and the highest elevation on land that is affected by storm waves

Beach

accumulation of sediment along the landward margin of the ocean

Tides

daily rise and fall in the elevation of ocean surface at a specific location; caused by gravitational attraction of the moon and the sun

Hydrological Cycle

continuous interchange of water among oceans, the atmosphere, and continents

Drainage Basin

the land area that contributes water to a stream

Groundwater

water that occupies spaces in the bedrock (water table), largest reservoir of freshwater available to humans

Spring

intersection of a water table to the surface

Geyser

heated groundwater that expands and changes to steam, causing a water eruption

Thermosphere

where space shuttles orbit, gases here are not distributed uniformly, temperature increases as altitude increases

Mesosphere

where meteors burn up, temperature decreases as altitude increases

Stratosphere

site of absorption of ultraviolet radiation due to high concentration of ozone (O3), temperature increases as altitude increases

Troposphere

site of most weather phenomena, temperature decreases as altitude increases

Air Mass

large body of air with the same temperature and moisture content

Air Pressure

downward force exerted by air molecules

Anticyclone

center of high-pressure regions, fair and clear weather is expected

Climate

generalization of weather conditions of a place over a long period of time

Clouds

condensed visible aggregates of water droplets or ice crystals

Cirrus

type of clouds / high, white, and thin

Cumulus

type of clouds / consist of globular individual masses

Stratus

type of clouds / low lying, sheet-like

Cyclone

air mass rotating around a low-pressure center; cloudy conditions and precipitation are expected

El Niño

periodic warming of the central and eastern parts of the pacific ocean

Fog

cloud with a base at or near the ground

Front

separates air masses of different densities

Humidity

describes the amount of water vapor in the air

Hurricanes

tropical cyclones with wind speeds exceeding 119 kph

La Niña

periodic cooling of the central and eastern parts of the pacific ocean

Precipitation

joining of several small cloud droplets, may be in the form of rain, snow, sleet, glaze, hail, or rime

Thunderstorms

caused by the upwards movement of warm, moist air, associated with cumulonimbus clouds

Tornadoes

violent windstorms taking the form of a rotating column of air that extends down a cumulonimbus cloud

Weather

state of the atmosphere at a certain period of time

Elements of Weather

air temperature, relative humidity, cloudiness, precipitation, air pressure, wind speed

Wind

flow of air from areas of high to low pressure

Geocentric

Ptolemy / belief that the earth is the center of the solar system/universe

Heliocentric

belief that the sun is the center of the solar system

Rotation

circular motion of earth about its own axis

Revolution

movement of earth in its orbit around the sun

Precession

a slow motion of Earth's axis that traces out a cone over a period of 26,000 years

Solar Eclipse

occur when the moon is directly between the sun and the earth / moon = middle

Lunar Eclipse

occurs when the Earth is directly between the sun and moon