ADVECTION FOG: Occurs when moist air passes over a cool surface via wind and is cooled. It is most common at sea when the tropical air collides with the cooler waters.
Thursday, April 29, 2010
Frontal or Cyclonic Rainfall
ADVECTION FOG: Occurs when moist air passes over a cool surface via wind and is cooled. It is most common at sea when the tropical air collides with the cooler waters.
Orographic Precipitation
OROGRAPHIC UPLIFT: Occurs when air is forced to rise and cool due to features such as hills or mountains. If the cooling is enough then water vapor will turn into clouds, and even more cooling can result in rain or snow. This means that there are often more clouds and rain or snow in higher regions.
ADIBATIC HEATING: Is a change in temperature due changes in the pressure of a gas while not adding or subtracting any heat. Adibatic heating occurs when the pressure of a gas is increased. It is common in convective currents in the atmosphere. As a mass of air descends in the atmosphere, such as when it moves downslope on a mountain range, the air encounters increasing pressure. Compression of this air mass means an increase in temperature.
CHINOOK WIND: Along the eastern slopes of the Rocky Mountains the Chinook wind is a lovely warm breeze during the winter season. These winds are caused by most weather patterns coming from the Pacific coast, cooling as they climb the western slopes of the mountain and then quickly warming as they come down the eastern side. They often begin with a sudden change in the direction of the wind towards the west and in increase of the speed of the wind.
WINDWARD SIDE: The side of something such as a mountain or hill that is facing the wind. The direction the wind is blowing towards.
LEEWARD SIDE: The side of a hill or mountain that is sheltered from the wind. The direction in which the wind is blowing.
RAIN SHADOW: A dry area on the mountainside that is facing away from the direction of the wind. A mountain or hill blocks the passage of rain producing clouds causing a "shadow" or dryness to follow behind them. This occurs because as warm moist air rises to the top of a mountain it cool and rains on the top of the mountain. Then as the air comes back down it has lost all of its moisture and has no more to precipitate.
ADIBATIC HEATING: Is a change in temperature due changes in the pressure of a gas while not adding or subtracting any heat. Adibatic heating occurs when the pressure of a gas is increased. It is common in convective currents in the atmosphere. As a mass of air descends in the atmosphere, such as when it moves downslope on a mountain range, the air encounters increasing pressure. Compression of this air mass means an increase in temperature.
CHINOOK WIND: Along the eastern slopes of the Rocky Mountains the Chinook wind is a lovely warm breeze during the winter season. These winds are caused by most weather patterns coming from the Pacific coast, cooling as they climb the western slopes of the mountain and then quickly warming as they come down the eastern side. They often begin with a sudden change in the direction of the wind towards the west and in increase of the speed of the wind.
WINDWARD SIDE: The side of something such as a mountain or hill that is facing the wind. The direction the wind is blowing towards.
LEEWARD SIDE: The side of a hill or mountain that is sheltered from the wind. The direction in which the wind is blowing.
RAIN SHADOW: A dry area on the mountainside that is facing away from the direction of the wind. A mountain or hill blocks the passage of rain producing clouds causing a "shadow" or dryness to follow behind them. This occurs because as warm moist air rises to the top of a mountain it cool and rains on the top of the mountain. Then as the air comes back down it has lost all of its moisture and has no more to precipitate.
Convectional Rainfall
CUMULONIMBUS CLOUD: These occur at the same heights and with the same vertical growth as the cumulus clouds. These are towering thunderheads that bubble up through the troposphere. Due to the fact that they reach freezing altitudes they often become “crowned” with a giant feathering anvil top of ice crystals. They will produce heavy rain, thunder and lightning.
CONVECTIONAL OVERTURNING: The outer shell of a cumulus cloud is often quite stable and the pattern of it is very clear cut, because of the result of mixing cloud and unsaturated air. Toward the center of the cloud there is instability, due to mixing and increasing water content. The rate at which the mass of air in a cloud increases equals the rate of entrance through sidewalls and top, meaning the amount of air that goes in and out must be equal.
CONVECTION CURRENT: A current caused by the expansion of in this case a liquid as the temperature rises. The expanded material being less dense rises while the colder material will sink. They occur in the atmosphere above warm land masses or seas giving rise to sea and land breezes.
THUNDER: The sound of lightning, and depending on the distance or the the nature of the lightning the sound can either be a sharp loud crack, to a low long rumble. The quick increase in both temperature and and pressure from lightning creates rapid expansion of the air and this expansion creates a sonic shock wave. You can calculate the distance of lightning to you by the time between and the flash of light and the sound that follows.
Wednesday, April 28, 2010
Clouds
STRATUS: The base of these clouds can occur anywhere from almost ground level to about 5000 feet. They are rather dark and often have many layers with broken patches called fracto-stratus. It is quite thin and will really only produce a drizzle.
CUMULUS: These clouds often extend vertically quite high. The base can be anywhere from 1600 to 35000 feet. They are thick bubbling clouds with flat bases. Often blue sky surrounds them. They will not produce precipitation.
NIMBO STRATUS: These type of clouds occur close to the surface of the Earth. It is often thick, enough so that ice crystals can form but it will not produce precipitation.
Thursday, April 22, 2010
The Atmosphere
Stratosphere: Right above the troposphere and extends to about 50 km. It is both drier and less dense then the troposphere. This is often where flying equipment reaches its height. There are very few to no clouds in this region due to the lack of water vapour. Due to the lack of vertical convection in this layer it means that chemicals often stay there for very long periods of time.
Ozone Layer: The ozone layer if made up of three oxygen molecules, unlike the air that we breathe in which is made up of only two. When enough of these molecules are present it causes a pale blue gas to form. It has the same chemical structure in all layers of the atmosphere however depending on its location it is either good or bad ozone. The bad ozone occurs in the troposphere. It is an air pollutant that damages humans, vegetation and other materials. In the stratosphere is the good ozone which protects the life on earth from harmful UV rays. There is much worry about the build up of bad ozone, and the deteriorating of the good ozone.
Thursday, April 15, 2010
Desert Landforms
Bajada: When many alluvial fans all come together in one place, or deposit in the same area it creates a bajada. Because of the gathering of all the fans it means that there is much more water and sediment then usual, and it is quite evenly spread out throughout the whole bajada.
Pedestal Rock: A large bolder on top of a very narrow base. This occurs when there is soft rock underneath that is easily eroded and harder rock on top that can not be eroded away.
Despite the lack or limited amount of precipitation in deserts, water is the major agent of erosion. Rainfall when it comes is brief and intense, and due to the hard rocky surface and limited vegetation tends to RUN OFF, creating FLASH floods. Because of limited precipitation PHYSICAL weathering is dominant. The main physical processes are HEATING-COOLING ,FREEZING-THAWING, and EXFOLIATION. Despite the fact that water is the most important agent of erosion in deserts, wind is quite important too. The action of wind eroding, transporting and depositing sediments is called EOLIAN processes. Wind erosion is common because there is little VEGETATION to hold the sand or sediment in place. Deflation is the large scale removal of sediment by wind. Abrasion is the process where sand carried by the wind “sandblasts” rocks. Regions covered in sand are called SAND SEAS or ERGS. Regions which are bare rock are called DESERT PAVEMENTS or REGS in Algeria.
Longshore Drift and Headward Erosion
Longshore Drift: The transport of sediments, such as sand and gravel, along the coast at an angle to the shore which depends on the wind direction, waves and the backwash of waves. The initial waves moves sediment up the beach, then the backwash pushes it back down the beach. This creates a zig-zag movement of sediment on the coast. Large sediment is found updrift and the smaller sediment which is more usually moved is found downdrift.
Headward Erosion: Backwards erosion of material at the start of a river or stream. Gravel or soil at the source of the river are carried away causing the start of the river to move backwards as erosion takes place in the opposite direction of the flow of the river.
Tuesday, April 13, 2010
Coastal Landforms: Depositional Features
A terrace on the seacoast, formed by the merging of a wave-built terrace and a wave cut platform. An embankment of loose material on the coast.
Spit:
At one end spits are connected to the land, and on the other hand they are in open water. They are formed by the movement of sediment, usually sand, along the shore by the process of longshore drift. When the wave is no longer able to carry the load of
sediment then it is deposited in the form of a spit.
Barrier Island:
A coastal landform and type of barrier that are narrow strips of sand that run parallel to the land. They often occur in chains of many islands. Like spits they are formed by the dropping off of sediment.
Tombolo:
An island that is attached the mainland usually by a small strip of land such as a spit. When many of these islands are linked together then it is called a tombolo.
Bar:
An elevated reigon of sand or gravel that has been deposited by the flow of the ocean. There are many different kinds and they are often connected to things such as tomobolos or barrier islands.
Coastal Landforms: Erosional Features
Wave Cut Platform:
A narrow flat area found at the base of a sea cliff or along the shoreline or a body of water. They are often only visible at low tide, appearing as large areas of flat rocks. They are created by waves
undercut
ting a cliff, eventually it cuts so deep that the cliff is not able to support itself and breaks away creating a flat area.
Sea Cliff:
A significant vertical, or close to vertical rock exposure. They are often found on the coasts and occur where the rock is not prone to, or is strong against erosion and weathering.
Sea Cave:
A cave formed by the wave action of the sea. In order to form the cave the rock must have a weak zone. Rock is then eroded at a faster rate, however because the rest of the rock cliff is strong it is able to support the weight. Because of the confined space that the waves are often eroding it becomes stronger and more powerful and is able to go deep and far into the rock.
Arch:
Erosion from the ocean finds weak parts in the rock and cuts away at it creating a natural arch way under the rock. The strength of the rock means that it is able to maintain its shape, however erosion and weathering also cuts at the side meaning the support can be quite thin.
Stack:
Rock formation that stands alone and is no longer attached to a cliff. Like sea caves and arches the ocean works away at the weak part of the rock slowly breaking it free from the cliff it was once a part of. It usually begins as a cave in the rock, which then becomes an arch due to more erosion, and when finally the rock can not hold and breaks away it becomes a stack.
Monday, April 12, 2010
Oceans
Ocean Currents

1. Currents are the transfer of vast quantities of water from one place to another. The most obvious cause of the currents is the air above the oceans. Winds literally push waters along by catching on to waves ad ripples of the ocean. Another cause of ocean currents is the difference in temperature from the water at the Equator and the water that is further North and South. This causes the water to move in a gyre, or a circular motion, clockwise in the Northern Hemisphere and counter-clockwise in the Southern Hemisphere. Another cause for this gyre movement is Coriolis Force, or a deflective force caused by the rotation of the Earth. The last cause for the currents in the ocean is the salinity or the saltiness of the water, causing more dense water to flow in currents.
2. Peru Current on the Coast of Chile: This current causes for the coast of Chile to have the most abundant fish population of anywhere in the world and about 18-20% of the worlds fish catching comes from this area. It also causes for the temperature of Chile to not be over heated, and for their to be some cooler areas.
Gulf Stream on the weather conditions in Newfoundland: Warm surface waters always move into colder latitudes, and then return from polar ares in the form of strong currents such as the Labrador current off the coast of Eastern Canada. This current slips under the Gulf Stream, which is always warmer then the surrounding waters. Because of this difference in temperature from the climate of the landscape and the water the Earth's temperature is able to be regulated. If not for currents like these then the polar reigons of the Earth would get MUCH colder and the tropical environments would get MUCH warmer.
Tides
1. Causes: Tides are influenced by both the gravitational pull of the sun, and more strongly the pull of the moon. When the moon is overhead it pulls the water toward it, causing more water to go to one side of the Earth, or a high tide. As the moon goes around the world in a day, it pulls the water with it. When the sun and the moon pull the water in the same direction it causes for a very high tide, or a SPRING TIDE. When the moon and the sun pull it from both directions then it causes for a low - high tide or a NEAP TIDE.
2. How are Tides Beneficial?
-High tides are used to drive turbines and to produce electricity in some areas of the world.
-Boats are also able to use the changing of the Earth's tide to their advantage and make it more easy for them to travel the world.
- When the tide comes in it brings with a variety of marine life, meaning for good fishing.
Wednesday, April 7, 2010
Groundwater and Aquifers
Importance of Groundwater in my Community, Canada, and the World:
Community: The province of British Colombia has 28.5% of the population using groundwater for domestic purposes.
Canada: 8.9 million or 30.3% of the population rely on groundwater for domestic use.
The World: 20% of the world's fresh water supply.
Artesian Well:
Man's Impact on Groundwater and Aquifers:
Ogallala Aquifer: Covering an area of 450 000 square km, it is one of the world's largest aquifers, located in the Great Plains of the US. It yields about 30% of the groundwater used for irrigation of farms, as well as 82% of the water used for drinking in the area.Urban Water Cycle: A project with countries around the North Sea working to develop solutions to their water problems. Holland, Germany, England, and Denmark all share their ideas on how they sustain and provide water for their countries, and together by sharing their ideas and seeing what has been working and not working they are developing the best way to sustain and use the water we have in the world.
Walkerton, Ontario: In May 2008 the water supply of Walkerton, Ontario was contaminated with the E.coli bacteria from farm run off into an adjacent well. Half of the population of the small town of 5000 became ill from the water, and 7 died due to the fact that the city did not admit to the problem earlier on.
Impacts in Canada: Things such as septic systems, leaky tanks or pipes, spills of chemicals, landfills, livestock waste, graveyards, and chemicals used on farms all have an impact on the safety of the ground water in Canada. Some contamination can be so bad that the groundwater can be completely unusable, which obviously has a large impact on Canada seeing that many people rely on it for their water needs.
Thursday, April 1, 2010
Stream Cycle
Youthful Stream
Youthful Stream: A steep gradient, and a fairly straight channel. For the most part it flows in a V-shaped valley in highlands of mountainous areas with very little shifting of its channel. It reaches quite high speeds, and it works at lowering its channel through downcutting so that it can reach the base level. It has a very little floodplain, and rapids and waterfalls may be on its course.Mature Stream
Mature Stream: A stream in its middle stage has a medium gradient and speed because it has eroded the bed downward and gotten closer to the base level. Though it is still eroding downwards it mainly erodes laterally.
Old Age Stream
Old Age Stream: A stream that has nearly reached the base level. Its gradient and speed are very slow, and because of this it has lost the power to erode downwards. It deposits as much as it erodes, and has a wide well developed floodplain defined by oxbow lakes.Flood Plain: Flat land adjacent to a stream or river created by the stream flooding over and leaving deposits of rock and soil. This land often experiences flooding.
Oxbow Lakes: A U-shaped body of water that has been formed when a wide meander of a stream or river is cut off to create a lake.
Stream Rejuvenation
Paired Terraces: A terrace on the same level of either side of a stream or river. This occurs when the water downcuts evenly on both side of a valley.
Meander: A bend or a loop in a streams course
V-Shaped Valley: An erosional feature created by a stream. A stream erodes a fairly narrow path through the landscape, often trying to get to the base level. If the rock it is cutting through is weak and breaks away easily then it will most likely cause a steep v-shaped valley with more rock cut away at the top and less at the bottom.
Interfluve: A region of higher land between two rivers that are in the same drainage system.
Divide: A division or split of a drainage system by higher land that causes them to drain into different bodies of water.
Parts of a Drainage Basin/Watershed
Tributaries: A stream or river that flows into a main or parent river. It does not directly flow into a large body of water like an ocean or lake, but instead connects up to a river that does.
Distributaries: A stream or river that branches off of the main or parent river. It then can lead to a larger body of water, or in some cases it might steal so much water from the parent river that it becomes the main.
Yazoo Streams: A stream that runs parallel to a river, and eventually joins up to it.
Confluence: The meeting of two or more bodies of water. It usually refers to the tributary of two rivers or streams meeting up but sometimes it can be two channels, or a channel and a lake.
Estuary: A partly enclosed coastal body of water with one or more rivers flowing into it and an open connection to the sea. It is prone to both ocean and river influences.
Braided Stream: A stream with many small shallow channels that divide and recombine many times creating a braided pattern. They form when a sediment load is too heavy and it has to be deposited along the channel.
Groundwater: Water that is located beneath the surface of the Earth in pores in the soil.
Drainage Patterns
Trellis: A type of drainage system. As a river flows down a valley, smaller tributaries flow into it from the slopes of mountains at a 90 degree angle causing it to have the trellis appearance.
Radial: A type of drainage system. Streams radiate outwards from a high central point. Volcanoes often have this feature.
Dendritic: The most common form of drainage system. Form in v-shaped valley where many small tributaries join together and then join onto a main river, giving it the appearance of a tree.
Deranged: A type of drainage system with no coherent pattern or system. It occurs where there has been much upset or disruption of the surrounding area.
Radial: A type of drainage system. Streams radiate outwards from a high central point. Volcanoes often have this feature.
Deranged: A type of drainage system with no coherent pattern or system. It occurs where there has been much upset or disruption of the surrounding area.
Subscribe to:
Posts (Atom)