The Water Cycle Water turns into steam by evaporation and transpiration ground back to the oceans, lakes a plants. It then condenses in the lower atmosphere & eventually precipitate s as rain, snow, etc. The water then flows over the ground as rivers and under the (oceans and lakes) (evaporation directly from plant leaves). 1
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The Water Cycle Water turns into steam by evaporation and transpiration ground back to the oceans, lakes and plants. It then condenses in the lower atmosphere.
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The Water CycleWater turns into steam by evaporation
and transpiration
ground back to the oceans, lakes and plants.
It then condenses in the lower atmosphere & eventually precipitates asrain, snow, etc.The water then flows over the ground as rivers and under the
(oceans and lakes)(evaporation directly from plant leaves).
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When air warms up, more water evaporates or transpires. This makes warm, humid air and when you warm a fluid, the warm, humid air willexpand, become less dense and rise.
As the air rises, it cools and then it will becomemore dense and it will eventually sink.
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Weathering and ErosionWeathering Physical - breaks rock into smaller
pieces without changing chemical composition Ice
When water freezes to form ice, the water expands. This expansion acts like a wedge and opens the gaps the water has entered
Plants Plant roots grow into the small
crack in rocks. Once there they provide a strong force that gradually pries the rock apart through the cracks
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Erosion by Water
Meanders & Oxbow lakes are formed by surface water erosion on level or gently sloping land
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Chemical – process in which rock is broken down by chemical reactions. Water is an effective solvent that dissolves the
minerals in rock, changing them over time Rusting of minerals rich in iron involves
oxidation acid rain can dissolve minerals (water and
carbon dioxide combine to form carbonic acid) The carbonic acid in the rain water can dissolve
minerals causing underground caves 1990 the acid rain act was added to the 1970
clean air act that required power plants and factories to reduce the release of sulfur dioxide
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ErosionErosion - process by which rock and /or the products of
weathering are removed.
Water – running water erodes land Moving water scrapes the earth and carries sediment
away to new places. Faster water carries heavier sediments while slower
water cannot, resulting in the releasing of these sediments
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Other Water Terms
Longshore drift moves sand along the shore.
A sea stack is formed by wave erosion.
Density differences in ocean water cause deep currents.
An upwelling brings cold water from deep ocean to the surface
Glaciers – Constantly moving masses of ice exert tremendous force on surrounding forces on rock. Can carry huge amounts of sediment As the glaciers move
they create U-shaped valleys as they cut across the landscape
As the glacier melts it will deposit its sediment to create a new landforms.
Portage Glacier in Alaska - probably the most visited glacier in AK.
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Moraine
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A mound of sediment at the downhill end and sides of a glacier
Medial moraine visible as a dark line along the centre of the glacier. Wide lateral moraines can be seen on either side.
that is saturated with waterLandslide – rock and soil
moving down a slope rapidly
Creep – fences curving down a hillside
Delta – soil deposited when river flows into an ocean
Deep ocean currents – result of density differences in H20
Upwelling – ocean current rising cold, deep H20
Longshore Drift – process that moves sand along shore
Frost wedging – water frozen is cracks pushed out soil and rock
Most of Earth’s fresh water is found in groundwater.
A stream’s ability to erode is a result of its speed
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Weathering TermsChemical Weathering
Agents:Rainwater, oxidation,
carbonic acid
Chemical weathering – evident most on limestone in hot, rainy area
Cave & sinkhole formation – by chem weathering
Caves can be formed by groundwater formation
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Other Important TermsRadioactive Isotopes
– used to more precisely determine the age of rocks
Rad. Isotopes, Index fossils, relative dating – used to determine age of sedimentary rocks in different locations
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Alluvial Fan
• Alluvial Fan• Credit: USGS EROS Data Center; NASA • A vast alluvial fan blossoms across the desolate landscape
between the Kunlun and Altun Mountains that form the southern border of the Taklimakan Desert in China's XinJiang Province. The river appears electric blue as it runs out of the mountains at the bottom right corner of the scene and then fans out into scores of intricate, braided channels that disappear into the desert. Dry channels - the river's former paths - appear as silvery etchings at lower right. This scene was acquired by the ASTER instrument on NASA's Terra satellite on May 2, 2002
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Alluvial FanCredit: USGS EROS Data Center; NASA A vast alluvial fan blossoms across the desolate landscape between the Kunlun and Altun Mountains that form the southern border of the Taklimakan Desert in China's XinJiang Province. The river appears electric blue as it runs out of the mountains at the bottom right corner of the scene and then fans out into scores of intricate, braided channels that disappear into the desert. Dry channels - the river's former paths - appear as silvery etchings at lower right. This scene was acquired by the ASTER instrument on NASA's Terra satellite on May 2, 2002
Glacial Horn in Nepal
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Sinkholes are depressions or holes in the land surface that occur throughout west central Florida. They can be shallow or deep, small or large, but all are a result of the dissolving of the underlying limestone.
Hydrologic conditions, including lack of rainfall, lowered water levels, or, conversely, excessive rainfall in a short period of time, can all contribute to sinkhole development. More facts about sinkholes can be found in the District’s
Earth’s History
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Geologists use the law of superposition to determine the relative age of rocks.In sedimentary rock, older rock is in a
deeper levelIndex fossils that lived during a well-
defined period of time are used to determine relative age, also.
Radioactive dating is used to determine the absolute ages of rocks.Half life is the time it takes for half of a
radioactive substance to change into something else. Seeing how many half lives have passed, can be used to tell how much time has passed; and how old something is.
Exploring Radioactive Dating
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1. A fossil contains 40.0 milligrams of U-238, which has a half life of 4.5 billion years. How much U-238 will remain after two half lives?
40.0 mg divided by 2 divided by 2 = 40/4 =10.0 mg2. How long will it take for 50.0 mg of Th-232 in a rock
to decay to 25.0 mg? One half life for Th-232 is 14.0 billion years.
25/50 = s½ so, 1 half life or 14.0 billion years3. How long will it take for 80.0 mg of Rb-87 to
decay into 10.0 mg? T½ for Rb-87 is 48.8 billion years.
10/80 = 1/8 = 1/23 . The exponent tells 3 half lives so 3 x 48.8 billion years = 146.4 billion years !!!