Integrated Science Ch 33
what is the difference between plains and plateaus?
PLAINS are broad, flat areas that don't rise far above sea level. PLATEAUS on the other hand, are flat areas uplifted more than 600 m above sea level
name and describe the three main types of volcanoes
Shield volcanoes = broad, gentle slopes; erupt thin, runny lava that spreads out over the land, has Basaltic lava has a low viscosity (flows easily) cinder cones = small volcanoes with steep sides, built from various ejected materials, including ash, cinders, glass and lava fragments, and rocks; materials erupt explosively and pile up at a steep angle composite cones = they have steep summits but gently sloping lower flanks; they are built of layers of lava, ash, and mud; Mt. St. Helens
why is folded rock usually produced deep underground?
because deeper underground it is hotter and because it is hotter magma is able to run further which produces folded rock
plains
broad, flat areas of land that don't rise above sea level
how are folded mountains formed?
by the compression and complex folding of layers of rock EXAMPLE: Himalayas
how are landforms such as valleys and canyons produced?
by weathering and erosion, the action of water, wind or ice wearing down and transporting rock
reservoir
a location where water or other material that transfers from place to place in a cyclical manner is stored
runoff
precipitation that is not absorbed by the ground or evaporated and that runs over the earth's surface
what are the three ways the ocean changes as you go deeper?
1. the deeper you go the less light there is -sunlight can penetrate only up to about 200m, so the deep ocean is black 2. temperature decreases with depth -the bottom of the ocean is dense and near freezing; dense, cold water of the ocean bottom mixes very little with water near the surface 3. pressure increases with depth -pressure in the abyssal plains is several hundred times atmospheric pressure
how much of the earth is covered by ocean?
3/4
what is a water table and where is it located?
?... the upper boundary of the saturated zone
fold
a bend in layers of rock
what is a fault?
a break in the rock if the rock on both sides have moved relative to one another
fault
a crack in Earth's crust along which different sections of rocks have shifted
upwarped mountain
a dome-shaped mountain produced by a broad arching of Earth's crust
glacier
a large mass of dense ice formed from snow
fault-block mountain
a mountain produced by normal faulting and the uplifting of blocks of rock
folded mountain
a mountain produced by the folding of rock
volcano
a mountain that is the accumulation of lava or other erupted materials
compression (stress)
a squeezing force on rock
tension (stress)
a stretching force on the rock
what is an aquifer and how does it get replenished?
a zone of rock that groundwater can flow through, high porosity and high permeability, contain enormous amount of groundwater Groundwater continues to collect as precipitation percolates down from the surface, process of recharging is very slow, groundwater is a non renewable resource
Aquifer
a zone of water-bearing rock through which groundwater can flow
saturated zone
an underground region where all the open spaces are filled with water
how does the water cycle work?
as water flows it also changes phase, evaporating and condensing in different parts of the cycle. the sun gives water the energy it needs to evaporate. Gravity supplies the force that pulls water back to Earth's surface as precipitation (rain, snow, sleet, or hail). Gravity's constant pull moves water across Earth's surface downhill toward the ocean. when precipitation falls on the ocean, the water is completed quickly because it evaporates directly back to the atmosphere. precipitation falling on land can take a longer time to complete the cycle because it may become part of a snowpack or glacier and be locked up as ice for many years. or it may soak deep underground through infiltration and be stored as groundwater. eventually, even water stored as ice or groundwater evaporates into the atmosphere or flows through rocks and cracks, ultimately reaching the ocean. the cycle begins again as the ocean's water precipitates
water pollution
chemical, physical, or biological material introduced into water that harms organisms that depend on the water
define and describe precipitation?
rain, snow, sleet, or hail; gravity supplies the force that pulls water back to Earth's surface such as precipitation
what is a reservoir?
each of the places water is stored as it moves through the water cycle (glaciers, oceans, underground storage areas)
plateau
flat areas of land more than 600 m above sea level
What is an abyssal plain?
flattest places on earth because thick accumulations of sediment bury the uneven and rocky oceanic crust; there is less than a 1 ft vertical change for every 1000 square feet of area in the abyssal plains - they are literally flatter than a pancake
what is water in this saturated zone called?
groundwater
how much of the Earth is fresh water and where is most of it found?
less than 3% of the Earth is freshwater and most of it is found as solid ice and snow in the mountains and in polar regions
what is salinity?
measure of the amount of dissolved salts in a given amount of water
Why do mountains exist?
mountains exist because of the movement of tetonic plates
how are fault-block mountains formed?
mountains that form from tension and have at least one side bounded by a normal fault; tetonic forces also pull apart
what is the difference between normal faulting, reverse faulting, and strike-slip faults?
normal faults - indicate that rock has undergone tension, the plates are pulling away from each other reverse faults - typically occur where there has been compression, the rocks are being squeezed together strike slip faults - opposing forces cause plates to move horizontally, large strike slip faults at transform plate boundaries are called transform faults
what is tension?
occurs where masses of rock are pulling away from one another EXAMPLE: at divergent plate boundaries
what is the difference between point pollution and non-point pollution?
point = pollution due to a specific source (wastewater treatment plants) non-point =doesn't come from a single source (salt applied to roadways)
how is a glacier formed?
snow rarely melts in extremely cold places, it piles up year after year, the weight of overlying snow crushes buried snow into ice crystals, a giant mass the size of football fields or even a continent is produced
what is residence time and which reservoir holds water the longest?
the average amount of time that a water molecule spends in each reservoir; oceans hold water the longest (3200 years)
residence time
the average length of time that any given atom will stay in a particular reservoir, such as the ocean or atmosphere
what is the biggest divide in North America and what does it separate?
the continental divide separates the Pacific basin from the Atlantic basin
water cycle
the continuous movement of water in all of its phases among Earth's reservoirs
permeability
the ease with which fluid can flow through rock
how do creationists believe the mid-ocean ridge came to be?
the flood; water came shooting out of the ground and caused ridges
what produces the stresses that fault and fold rock?
the forces that produce folding usually come from the collision of tetonic plates; also, magma sometimes pushes against rock and compresses it
what causes water pollution?
the growth of large-scale factories and the human population explosion
watershed
the land area that drains into a particular stream
why does the ocean not get saltier over time?
the ocean's salinity is constant because salts are removed as quickly as they are added EXAMPLE: heavy rains (freshwater) dilute the ocean salt precipitates out of water when the water becomes saturated biology helps maintain the constant salinity of seawater; marine organisms remove salts from the ocean as well as dissolved gases, and other solutes
porosity
the proportion of rock that consists of pore spaces
what is topography?
the shape of the Earth's surface
continental margin
the transition zone between dry land and the ocean bottom
water table
the upper boundary of the saturation zone
ocean basin
the vast depression on Earth's surface underlain by oceanic crust and filled with ocean water
groundwater
the water that resides in a saturated zone
how are upwarped mountains formed?
they form from magma that wells up under Earth's surface and pushes it outward, over millions of years, the magma under the dome cools to become a solid core, eventually, erosion wears away soft surface rock, and durable igneous or metamorphic rock is exposed as an upwarped mountain
why do Geologists map faults?
to locate these resources (faults affect the distribution of groundwater, minerals, and fossil fuels)
what is compression?
when two tetonic plates collide, massive blocks of rocks are squeezed together