Earth Science (Chapter 7-16) Flashcards
Earth Science by Tarbuck, Lutgens, and Tasa
Together with his associates, he constructed a map that pieced together the edges of the continental shelves of South America and Africa.
Edward Bullard
The title of the book written by Alfred Wegener to support the Continental Drift Theory.
The Origin of Continents and Oceans
Divergent and convergent plate boundaries each account for about ________ of all plate boundaries. Transform faults account for the remaining __________.
40 percent; 20 percent
The majority of, but not all, divergent plate boundaries are associated with
mid-oceanic ridges (MOR)
the longest topographic feature on Earth’s surface, exceeding 70,000 kilometers (43,000 miles) in length.
Global ridge system
along the crest of some ridge segments is a deep canyonlike structure called
rift valley
Typical rates of seafloor-spreading average around ______ per year.
5 centimeters (2 inches)
Where can we found fastest and slowest spreading rates.
15cm/yr - East Pacific Rise; 2cm/yr Mid-Atlantic Ridge
the tallest peaks in Africa
Mount Kilimanjaro and Mount Kenya
A volcanic arc in Atlantic that forms through the subduction of the Atlantic seafloor beneath the Caribbean plate.
Lesser Antilles arc
An island arc located off the tip of South America.
Sandwich Islands
The nature of transform faults was discovered in 1965 by Canadian geologist ______.
J. Tuzo Wilson
When did the Arabian plate begin to split from Africa forming the Red Sea?
20 million years ago
the last remnant of a once vast ocean called Tethys Ocean
Mediterranean sea
a drilling ship capable of working in water thousands of meters deep, was built for Deep Sea Drilling Project from 1968-1983.
Glomar Challenger
IODP means
Integrated Ocean Drilling Program (IODP).
The two drilling ships that was utilized in IODP.
JOIDES Resolution (2003) and Chikyu (2007)
The major divisions of the mag netic time scale last roughly 1 million years.
chrons
This convection is a driving force for the movement of tectonic plates, asthe horizontal movements of mantle under the crust drag the plates with them.
Mantle drag
He concluded that the earthquake must have involved an “elastic rebound” of previously stored elastic stress.
H. F. Reid of Johns Hopkins University
Large strike-slip faults that slice through Earth’s lithosphere and accommodate motion between two tectonic plates
Transform Fault
San Andreas fault separates what plates?
North American and Pacific Plate
the plate boundary between a subducting slab of oceanic lithosphere and the overlying plate form a fault referred to as
megathrust fault
The earliest known instrument used to measure earthquakes are made by?
Zhang Heng
How wide is the maximum area from the epicenter that an earthquake can be felt roughly?
20 to 50 kilometers
An earthquake that provided geologists with insights into the role of ground shaking as a destructive force.
1964 Alaskan earthquake, also known as theGreat Alaskan earthquakeand Good Friday earthquake
What type of faulting triggered the 1964 Alaskan earthquake?
megathrust fault It had a moment magnitude of 9.2, making it the second largest earthquake on record.
The zone of greatest seismic activity is called?
circum-Pacific belt
The circum-Pacific belt encompasses the coastal regions of?
Chile, Central America, Indone sia, Japan, and Alaska, including the Aleutian islands
A major concentration of strong seismic activity that runs through the mountainous regions that flank the Mediterranean Sea and extends past the Himalayan Mountains
Alpine–Himalayan belt
The last major earthquke event in San Andreas Fault that occurred in Pallet Creek segment in 1857, roughly 150 years ago.
Fort Tejon
Lavas that have have surfaces of rough, jagged blocks with dangerously sharp edges and spiny projections.
Aa lava
What is the diameter of a caldera?
more than 1km
From its base on the floor of the Pacific Ocean to its summit, Mauna Loa is over_________ high, exceeding the elevation of Mount Everest.
9 kilometers (6 miles)
Most of the recent activity on Kilauea has occurred along the flanks of the volcano, in a region called
East Rift Zone
A cinder and spatter cone that formed when the eruption of Mt. Kilauea became localized at a single vent and a series of 44 short-lived episodes of lava fountaining
Puu Oo
A cinder cone located in Mexico, erupted for nine years.
Parícutin
Well known for eruptions that eject incandescent blobs of lava that it has been referred to as the “Lighthouse of the Mediterranean.”
Stromboli
When was the most recent volcanic activity of Mt. Vesavius?
1944
Refers to dense cloud of tiny sulfuric-acid droplets. Like fine ash, they can alsolower the mean temperature of the atmosphere by reflecting solar radiation back to space.
aerosols
Other term for craters
collapse pits
Term used for intrusions that cut across existing structures
discordant
It refers to an intrusion if they inject parallel to features such as sedimentary strata
concordant
These are discordant bodies that cut across bedding surfaces or other structures in the country rock
Dikes
Refers to nearly horizontal, concordant bodies that form when magma exploits weaknesses between sedimentary beds or other structures
Sills
The thickness of dikes and sills ranges from
less than 1 millimeter to more than 1 kilometer
While dikes and sills can occur as solitary bodies, dikes tend to form in roughly parallel groups called
dike swarms
occurs when igneous rocks cool and develop shrinkage frac tures that produce elongated, pillar-like columns that most often have six sides
Columnar jointing
A plutonic body must have a surface exposure of ________ in order to be considered a batholith
greater than 100 square kilometers
Smaller plutons are termed as
stock
Who gave the name laccoliths?
G. K. Gilbert
A mass ofigneousrock, typically lens-shaped, that has beenintrudedbetween rockstratacausingupliftin the shape of a dome.
Laccoliths
What is the temperature for geothermal gradient?
25°C per kilometer in the upper crust
Occurs where hot, solid mantle rock ascends in zones of convective upwelling, thereby mov ing into regions of lower pressure
Decompression melting
Most intraplate volcanism occurs where a mass of hotter-than-normal mantle material called
Mantle Plumes
A general term that refers to the changes in the shape or position of a rock body in response to differential stress.
Deformation
stress is applied uniformly in all directions
confining pressure
stress is applied unequally in different directions
differential stress
A change in shape caused by stress.
strain
Each layer of a fold is bent around an imaginary axis called a
hinge line
These are produced by rapid vertical slips in dip-slips that generate earthquakes.
fault scarps
when the hanging wall block moves down relative to the footwall block
normal fault
produced by alternating uplifted fault blocks
horst
down-dropped fault blocks
graben
fault blocks that have been tilted
half-grabens
the slopes of the large normal faults associated with the Basin and Range Province decrease with depth and eventually join to form a nearly horizontal fault called
Detachment fault
strike-slip faults that slice through Earth’s crust and accommodate motion between two tectonic plates
Transform Fault
fractures along which no appre ciable displacement has occurred
joints
This type of mountain building is characterized by subduction beneath a continent rather than oceanic lithosphere.
Andean-type mountain Building
The resulting chaotic accumulation of deformed and thrust-faulted sediments and scraps of ocean crust
Accretionary wedge
As an accretionary wedge grows upward, it acts as a barrier to the movement of sediment from the volcanic arc to the trench. As a result, sediments begin to collect between the accretionary wedge and the volcanic arc. This region, which is composed of relatively undeformed layers of sediment and sedimentary rocks
forearc basins
a crustal fragment that consists of a distinct and recognizable series of rock formations that has been transported by plate tectonic processes.
terrane
eastern portion of the Pacific basin
Farallon plate
Much of the remaining penetration into Asia caused lateral displacement of large blocks of the Asian crust by a mechanism described as
continental escape
The Laramide Rockies in Rocky Mountains was produced duringa period of deformation known as the
Laramide Orogeny
involves ductile spreading at depth and normal faulting and subsidence in the upper, brittle portion of Earth’s crust.
gravitational collapse
Combining the principles of lateral continuity and superposition lets us extend relative age relationships over broad areas. This pro cess, called
correlation
Refers to a piece of rock trapped in another type of rock.
xenolith
These are “foreign” minerals incorporated into the magma during magma scent or during xenoliths fragmentation.
xenocrysts
When we observe layers of rock that have been deposited essentially without interruption, we call them
conformable
Represents a long period during which deposition ceased, erosion removed previously formed rocks, and then deposi tion resumed
unconformity
Where can we find fossils of mammoth?
Arctic tundra of Siberia and Alaska
Where can we find fossils of sloths?
dry cave in Nevada
When mineral-rich groundwater permeates porous tissue such as bone or wood, minerals precipitate out of solution and fill pores and empty spaces, a process called
permineralization
When a shell or another structure is buried in sediment and then dissolved by underground water, a ______ is created
mold
If these hollow spaces are subsequently filled with mineral matter, ______ are created
casts
Animal footprints made in soft sediment that later turned into sedimentary rock.
Tracks
Tubes in sediment, wood, or rock made by an animal. These holes may later become filled with mineral matter and preserved.
Burrows
Some of the oldest-known fossils are believed to be
worm burrows
Fossil dung and stomach contents that can provide useful information pertaining to the size and food habits of organisms
Coprolites
Highly polished stomach stones that were used in the grinding of food by some extinct reptiles
Gastroliths
To develop a geologic time scale that is applicable to the entire Earth, rocks of similar age in different regions must be matched up. Such a task is referred to as
correlation
a fossil that is useful for dating andcorrelatingthestratain which it is found
index fossil
Fossils that provide geological records of the activities and behaviors of past life. Some examples include rock evidence of nests, burrows, footprints, and scat.
trace fossils
other term for trace fossils
Ichnofossils
Refers to the fossils of bones, teeth, and shells.
body fossils
the property of some unstable atoms (radionuclides) to spontaneously emit nuclear radiation
radioactivity
It refers to the earliest interval (eon) of Earth history—before the oldest-known rocks.
Hadean
When the term “Hadean” was coined in 1972, the age of Earth’s oldest rocks was thought to be about
3.8 billion years
A well-known fossil of a human ancestor _________ was discovered in Ethiopia and is 3.2 million years old. The oldest bones thus far assigned to the human genus Homo, are from the early Pleistocene epoch and are about 2.4 million years old.
(Australopithecus afarensis) known as Lucy
This early atmosphere was enhanced by a process called __________, through which gases trapped in the planet’s interior are released
outgassing
alternating layers of iron-rich rocks and chert
banded iron formations
what era did the Great Oxygenation Event occur
Paleoproterozoic era of the Precambrian period
One apparent spike in oxy gen levels occurred during the _________, when oxygen made up about 35 percent of the atmosphere, compared to modern levels of only 21 percent.
Pennsylvanian period (300million years ago)
Another positive benefit of the Great Oxygenation Event is
oxygen molecules (O2) readily absorb ultraviolet radi ation and form ozone (O3)
The oldest-known sample of Earth is a 4.4-billion year-old zircon crystal can be found in
a metaconglomerate in the Jack Hills area of western Australia.
The large landmass in the Southern Hemisphere called Gondwana, comprised mainly of present day
South America, Africa, India, Australia, and Antarctica
The cold current, called ______, effectively isolated the entire Antarctic coast from the warm, poleward-directed currents in the southern oceans. As a result, most of the Antarctic landmass became covered with glacial ice.
West Wind Drift
In what period did the Gondwana and Laurasia collided forming Pangaea
Permian - Triassic
Considered as the world’s richest storehouse of dinosaur fossils. In what period did it formed?
Morrison Formation - Jurassic
The first known organisms were simple single-cell bacteria
prokaryotes
stony structures built by colonies of microscopic photosynthesising organisms called cyanobacteria
Stromatolite
This period was the golden age of trilobites
Cambrian
Trilobites developed a flexible exoskel eton of a protein called
chitin
These are mobile, highly developed mollusks that became the major predators of their time. Descendants of these include the squid, octopus, and chambered nautilus that inhabit our modern oceans.
cephalopods
This period marked the appearance of abundant cephalopods
Ordovician
By the late Devonian, this type of fish had evolved into air-breathing amphibians with strong legs yet retained a fishlike head and tail.
lobe-finned fish
They were the first true terrestrial animals with improved lungs for active lifestyles and “waterproof” skin that helped prevent the loss of body fluids.
Reptiles
produced “naked” seeds that are exposed on modified leaves that usually form cones
gymnosperms
Gymnosperms that resembled large pineapple plants
cycads
Gymnosperms that had fan-shaped leaves
ginkgo
the largest gymnosperm plants whose modern descendants include the pines, firs, and junipers
conifers
The largest herbivorous dinosaurs.
Apatosaurus
Largest carnivorous dinosaurs.
Tyrannosaurus
These are airborne dinosaurs the “dragons of the sky” that possessed huge membra nous wings that allowed them rudimentary flight.
pterosaurs
These ancestors of modern birds had feathered wings but retained reptilian characteristics, such as sharp teeth, clawed digits in the wings, and a long tail with many vertebrae.
Archaeopteryx
Referred to as fish-eating dinosaurs. These reptiles became proficient swimmers but retained their reptilian teeth and breathed by means of lungs rather than gills.
plesiosaurs and ichthyosaurs
These mammals are born very young and then move to a pouch on the mother.
marsupial mammals
These mammals spend a longer time in utero and are born in a relatively mature state compared to marsupials.
placental mammals
Anthropoids are also informally called?
apes
The genus ________ , which came into existence about 4.2 million years ago, showed skeletal characteristics that were intermediate between our apelike ancestors and modern humans.
Australopithecus
The earliest fossils of our genus Homo include_______ , nicknamed “handy man” because their remains were often found with sharp stone tools in sedimentary deposits from 2.4 to 1.5 million years ago
Homo habilis
During the next 1.3 million years of evolution, our ances tors developed substantially larger brains and long slender legs with hip joints adapted for long-distance walking.
Homo erectus
The oldest-known fossils of Homo sapiens outside Africa were found in the Middle East and date back to
115,000 years ago
Mastodons and mammoths can be found in?
North America
The oldest anatomically modern human fossils are _________ old.
200,000 years
Humans evolved from primate ancestors in ______ over a period of 8 million years.
Africa
called as the land hemisphere
Northern Hemisphere
Referred as the water hemisphere.
Southern Hemisphere
largest ocean and the largest single geographic feature on the planet
Pacific Ocean
Depth of Pacific Ocean
average depth of 3940 meters (12,927 feet, or about 2.5 miles)
about half the size of the Pacific Ocean and not quite as deep. It is a relatively narrow ocean compared to the Pacific and is bounded by almost parallel continental margins.
Atlantic Ocean
slightly smaller than the Atlantic Ocean but has about the same average depth. Unlike the Pacific and Atlantic Oceans, it is largely a Southern Hemisphere water body.
Indian Ocean
about 7 percent the size of the Pacific Ocean and is only a little more than one quarter as deep as the rest of the oceans.
Arctic Ocean
The meeting of currents near Antarctica is called the _______.
Antarctic Convergence
Oceanographers also recognize an additional ocean near the continent of Antarctica in the Southern Hemisphere. Defined by the meeting of currents near Antarctica called the Antarctic Convergence, it is actually those portions of the Pacific, Atlantic, and Indian Oceans south of about 50° south latitude.
Southern Ocean or Antarctic Ocean
The measurement of ocean depths and the charting of the shape (topography) of the ocean floor is known as
bathymetry
The basic approach used in measuring water depths as in sound energy is
sonar (sound navigation and ranging)
The first devices that used sound to measure water depth, called
echo sounders
the speed of sound waves in water
about 1500 meters (4900 feet) per second
Deep, steep-sided valleys known as ________ are cut into the continental slope and may extend across the entire continental rise to the deep-ocean basin
submarine canyons
Refers to the downslope movements of dense, sediment-laden water.
Turbidity Currents
deposits of turbidity currentsand commonly show graded bedding with a sequence of sedimentary structures indicative of waning flow during the passage of the turbidity current
turbidites
chaotic accumulation of deformed sediment and scraps of oceanic crust
Accretionary wedge
The opposite process of accretionary wedge. Rather than sediment accumulating along the front of the overriding plate, sediment and rock are scraped off the bottom of the overriding plate and transported into the mantle by the subducting plate. It is particularly effective when the angle of descent is steep.
Subduction erosion
are deep, incredibly flat features; in fact, these regions are likely the most level places on Earth.
Abyssal Plains
Submarine volcanoes
seamounts
These are eroded seamounts
guyots
The term guyot comes from the name of ________, Princeton University’s first geology professor.
Arnold Guyot
Seafloor sediment that consists primarily of mineral grains that were weathered from continental rocks and transported to the ocean.
Terrigenous Sediment
Consists of shells and skeletons of marine animals and algae. This debris is produced mostly by microscopic organisms living in the sunlit waters near the ocean surface.
Biogenous Sediment
The most common biogenous sediment and has the consistency of thick mud.
calcareous (CaCO3) ooze
composed primarily of tests of diatoms (single-celled algae) and radiolaria (single-celled animals)
siliceous (SiO2) ooze
Seafloor sediments that consists of minerals that crystallize directly from seawater through various chemical reactions.
Hydrogenous Sediment
are rounded, hard lumps of manganese, iron, and other metals that precipitate in concentric layers around a central object
Manganese nodules
form by precipitating directly from seawater in warm climates.
Calcium Carbonate
These are usually precipitated as coatings on rocks near black smokers associated with the crest of a mid-ocean ridge. These deposits contain iron, nickel, copper, zinc, silver, and other metals in varying proportions.
Metal Sulfides
form where evaporation rates are high and there is restricted open-ocean circulation.
Evaporites
are natural gas reservoirs in ice like crystalline solids found in sediments on the deep-ocean floor and in Arctic permafrost areas deeper than 200 meters (660 feet).
Gas Hydrates
Gas hydrates contain ______ which is the main ingredient of most natural gas—which is trapped within a lattice-like cage of water molecules.
methane molecules
Refers to the total amount of solid material dissolved in water. More specifically, it is the ratio of the mass of dissolved substances to the mass of the water sample.
salinity
the average salinity of seawater
3.50%
The layer of ocean water between about 300 meters (980 feet) and 1000 meters (3300 feet), where there is a rapid change of temperature with depth, is called the?
thermocline
experience a more dramatic seasonal thermocline and exhibit characteristics intermediate between high- and low-lati tude regions.
Midlatitude waters
The layer of ocean water between about 300 meters (980 feet) and 1000 meters (3300 feet), where there is a rapid change of density with depth, is called the?
pycnocline
A pycnocline is not present in high latitudes; instead, the water column is
isopycnal (iso = same, pycno = density)
organisms—algae, animals, and bacteria—that drift with ocean currents
plankton
photosynthetic planktons
phytoplankton
animal planktons
zooplankton
All animals capable of mov ing independently of ocean currents, by swimming or other means of propulsion, are called
nekton
most of Earth’s biomass—the mass of all living organisms—consists of ______ adrift in the oceans.
plankton
describes organisms living on or in the ocean bottom
benthos
An area in the deep-ocean floor that exhibit abundant life-forms
hydrothermal vents
The upper part of the ocean into which sunlight penetrates
Photic zone
A portion of the photic zone near the surface where light is strong enough for photosynthesis to occur.
Euphotic zone
Deeper part of the ocean where there is no sunlight.
Aphotic zone
Refers to the conversion of carbon atoms into organic compounds without sunlight for energy.
chemosynthesis
The area where the land and ocean meet and overlap is called the _________. This narrow strip of land between high and low tides is alter nately covered and uncovered by seawater with each tidal change.
intertidal zone
Seaward from the low-tide line is the_________. This covers the gently sloping continental shelf out to the shelf break.
neritic zone
Beyond the continental shelf is the?
oceanic zone
Open ocean of any depth is called the ________. Animals in this zone swim or float freely.
pelagic zone
The photic part of the pelagic zone is home to?
phytoplankton, zooplankton, and nekton
This part of the pelagic zone has strange species like viperfish and giant squid that are adapted to life in deep water.
aphotic part
Includes any sea-bottom surface, regardless of its distance from shore, and is mostly inhabited by benthos organisms.
benthic zone
A subdivision of the benthic zone and includes the deep-ocean floor, such as abyssal plains. This zone is characterized by extremely high water pressure, consistently low temperature, no sunlight, and sparse life.
abyssal zone
The amount of carbon fixed by organisms through the synthesis of organic matter using energy derived from solar radiation (photosynthesis) or chemical reactions (chemosynthesis).
Primary Productivity
The principal elements that contribute to the ocean’s salinity are?
chlorine (55%) and sodium (31%)
Huge, circular-moving current systems dominate the sur faces of the oceans. These large whirls of water within an ocean basin are called
gyres
The center of each gyre coincides with the subtropics at about 30° north or south latitude, so they are often called
subtropical gyres
In the North Atlantic, this zone of calmer waters is known as the
Sargasso Sea
The only current that completely encircles Earth is the
West Wind Drift
the temperature at which water vapor condenses
dew point
The rising of cold water from deeper layers to replace warmer surface water, is a common wind-induced vertical movement.
upwelling
It occurs when winds blow toward the equator and parallel to the coast
Coastal upwelling
An accumulation of sediment found along the landward margin of an ocean or a lake.
Beach
Beaches consist of one or more ______, which are relatively flat platforms often composed of sand that are adjacent to coastal dunes or cliffs and marked by a change in slope at the seaward edge.
berms
Part of the beach is the beach face, which is the wet sloping surface that extends from the berm to the shoreline.
beach face
The time it takes one full wave— one wavelength—to pass a fixed position
wave period
a critical point that is reached where waves grow so tall that they topple over, forming ocean breakers
whitecaps
As the wave travels, the water passes the energy along by moving in a circle.
circular orbital motion
The turbulent water created by breaking waves
surf
Refers to the bending of waves that affects the distribution of energy along the shore and thus strongly influences where and to what degree erosion, sediment transport, and deposition will take place.
wave refraction
Occurs as incoming waves carry sand at an angle up the beach, while the water from spent waves carries it directly down the slope of the beach.
beach drift
Concentrated movements of water that flow in the opposite direction of break ing waves
Rip currents
originate in the cutting action of the surf against the base of coastal land. As erosion progresses, rocks overhanging the notch at the base of the cliff crumble into the surf, and the cliff retreats.
wave-cut cliffs
A relatively flat, benchlike surface that is left behind by the receding cliff.
wave-cut platform
If a wave-cut platform is uplifted above sea level by tectonic forces, it becomes a
marine terrace
a sandbar that completely crosses a bay, sealing it off from the open ocean
baymouth bar
They develop either because an area experiences uplift or as a result of a drop in sea level.
Emergent coasts
They are created when sea level rises or the land adjacent to the sea subsides.
Submergent coasts
What type of coast exhibits rising land or falling water levels expose wave-cut cliffs and marine terraces above sea level.
Emergent coasts
They are often highly irregular because the sea typically floods the lower reaches of river valleys flowing into the ocean. The ridges separating the valleys, however, remain above sea level and project into the sea as headlands. These drowned river mouths, which are called estuaries, characterize many coasts today.
Submergent coasts
A tidal pattern that is characterized by a single high tide and a single low tide each tidal day.
diurnal tidal pattern
Exhibits two high tides and two low tides each tidal day, with the two highs about the same height and the two lows about the same height. This type of tidal pattern is common along the Atlantic coast of the United States.
semidiurnal tidal pattern
Similar to a semidiurnal pattern except that it is characterized by a large inequality in high water heights, low water heights, or both. In this case, there are usually two high and two low tides each day, with high tides of differ ent heights and low tides of different heights.
mixed tidal pattern
Refers to the the term used to describe the horizontal flow of water accompanying the rise and fall of the tides.
Tidal current
Tidal currents that advance into the coastal zone as the tide rises
flood currents
As the tide falls, seaward-moving water generates
ebb currents
Periods of little or no current, called _______, separate flood and ebb
slack water
The areas affected by these alternat ing tidal currents are called
tidal flats
Delta made by tidal currents in landward of an inlet
flood deltas
Delta made by tidal currents in the sea ward side of an inlet.
ebb deltas
Composition of Air:
78% nitrogen, 21% oxygen and 1 % other gases (Argon-0.9% and CO2-0.04%) and water vapour.
Refers to the state of the atmosphere at a given time and place.
weather
Describes the sum of all statistical weather information that helps describe a place or region.
climate
A mixture of many discrete gases, each with its own physical properties, in which varying quantities of tiny solid and liquid particles are suspended.
air
means “hidden heat”
latent heat
A collective term for tiny solid and liquid particles in the atmosphere such as sea salts from breaking waves, fine soil blown into the air, smoke and soot from fires, pollen and microorganisms lifted by the wind, ash and dust from volcanic eruptions.
aerosols
From a meteorological standpoint, what are the three significance of aerosols?
First, many act as surfaces on which water vapor can condense, an important function in the formation of clouds and fog. Second, aerosols can absorb, reflect, and scatter incoming solar radiation. Thus, when an airpollution episode is occurring or when ash fills the sky following a volcanic eruption, the amount of sunlight reaching Earth’s surface can be measurably reduced. Finally, aerosols contribute to an optical phenomenon we have all observed—the varied hues of red and orange at sunrise and sunset.
One-half of the atmosphere lies below an altitude of
5.6 km
90 percent of the atmosphere has been traversed at
16 kilometers
the average pressure at sea level
1000 millibars (mb)
It is in this atmospheric layer that essentially all important weather phenomena occur.
troposphere
The temperature decrease in the troposphere is called
environmental lapse rate
The average value of environmental lapse rate (temperature drop rate) in the troposphere.
6.5°C per kilometer
Refers to an instrument package that is attached to a balloon and transmits data by radio as it ascends through the atmosphere.
radiosonde
The outer boundary of the troposphere
tropopause
Atmospheric layer where the ozone layer can be found.
Stratosphere
The coldest temperatures anywhere in the atmosphere occur at the?
mesopause
When the Sun is directly over head, the rays strike the atmosphere at a 90-degree angle and travel the shortest possible route to the surface. This dis tance is referred to as
1 atmosphere
On June 21 or 22, Earth is in a position such that the north end of its axis is tilted 23½° toward the Sun. At this time, the vertical rays of the Sun strike 23½° north latitude (23½° north of the equator), a latitude known as the ________.
Tropic of Cancer
For people in the Northern Hemisphere, June 21 or 22 is known as the __________, the first “official” day of summer.
summer solstice
Six months later, on about December 21 or 22, Earth is in the opposite position, with the Sun’s vertical rays striking at 23½° south latitude. This parallel is known as the?
Tropic of Capricorn
For those in the Northern Hemisphere, December 21 and 22 is the
winter solstice
On these dates, the vertical rays of the Sun strike the equator (0° latitude) because Earth is in such a position in its orbit that the axis is tilted neither toward nor away from the Sun
equinox
the date of the autumnal (fall) equinox
September 22 or 23
the date of the spring equinox
March 21 or 22
The length of daylight is greater than the length of night.
summer solstice
the nights are longer than the days
winter solstice
During this season, the length of daylight is 12 hours everywhere on Earth, because the circle of illumination passes directly through the poles, dividing the latitudes in half.
equinox (meaning “equal night”)
refers to the quantity of energy present
heat
refers to the intensity—that is, the degree of “hotness.”
temperature
the transfer of heat through matter by molecular activity
conduction
the transfer of heat by mass movement or circu lation within a substance.
convection
heat transfer mechanism by which solar energy reaches our planet.
radiation
Have the longest wavelengths in the electromagnetic spectrum.
Radio waves (1-10 km)
Have the shortest wavelengths in the electromagnetic spectrum.
less than one-billionth of a centimeter long
has the shortest wavelength in the visible light
violet (0.4 µm)
has the longest wavelength in the visible light
red (0.7 µm)
The surface temperature of Sun.
nearly 6000°C
The surface temperature of Earth.
average surface temperature of about 15°C
The Sun radiates maximum energy at ________, which is in the visible range.
0.5 micrometer
The maximum radiation for Earth occurs at a wavelength of ________, well within the infrared (heat) range.
10 micrometers
The process whereby light bounces back from an object at the same angle at which it encounters a surface and with the same intensity.
Reflection
produces a larger number of weaker rays that travel in different directions.
scattering
The fraction of the total radiation that is reflected by a sur face is called
albedo
Although incoming solar radiation travels in a straight line, small dust particles and gas molecules in the atmosphere scatter some of this energy in all directions. The result, called _________, explains how light reaches into the area beneath a shade tree and how a room is lit in the absence of direct sunlight.
diffused light
poor absorber of all types of incoming solar radiation.
Nitrogen
efficient absorbers of ultraviolet radiation
Oxygen and ozone
Refers to a line that connects points on a map that have the same temperature.
Isotherm
Describes the amount of temperature change per unit of distance.
temperature gradient
Refers to any factor that causes temperature to vary from place to place and from time to time.
temperature control
known as the water hemisphere
Southern Hemisphere
A coastal location where prevailing winds blow from the ocean onto the shore.
wind ward coast
coastal location where the prevailing winds blow from the land toward the ocean
leeward coast
