Unit IV: Surface Processes & Landscapes Taken From: http://www-personal.umich.edu/~jensenl/visuals/album/2006/pictured/ on 1/5/07
What is weathering?
Weathering slides modified from work done by Caitlin F., Julianne R., Courtney G., Elizabeth R., Miranda B., Katie T., Mick M. and Brandan S..
The physical and chemical processes that change the characteristics of rocks on Earth’s surface.
>>> Break down of Earth’s materials <<<
Taken From www.geosci.unc.edu/faculty/glazner/Images/Weathering/weathering.html on 1/5/07 Cavernous weathering of granite on the island of Paros, Greece. This sort of weathering is common along many coastlines and probably results from deposition of salt in cracks (salt wedging).
Weathering is the response of rocks to change in their physical environment . A number of different factors in the environment can help cause weathering such as air, water in some form (ice, snow, liquid), gravity, and man.
Taken From: http://www-personal.umich.edu/~jensenl/visuals/album/2006/pictured/ on 1/5/07
Evidence of Weathering
The Weathering Process:
When rocks are exposed to the hydrosphere and the atmosphere the composition and characteristics of the rock change. The end products of weathering are sediments .
Taken From http://gpc.edu/~pgore/geology/geo101/weather.htm on 1/5/07 Exfoliation on Stone Mountain, Georgia
Sediments can be classified into a number of different groups including boulders, cobbles, pebbles, sand, silt, clay, collides, and dissolved particles (ionic materials).
Taken from http://www.uta.edu/paleomap/homepage/Schieberweb/Picture%20Pages/shphoto3.htm on 1/5/07 ESRT p.6
Describe the two types of weathering and give examples of each. Be able to tell how climate affects both types.
Physical Weathering- rocks are broken into smaller pieces without changing the chemical nature of the rock.
Taken from http://gpc.edu/~pgore/geology/geo101/weather.htm on 1/5/07
Example of Physical Weathering
When water goes into the crack of a rock then freezes causing the rock to break because water expands when frozen.
http://regentsprep.org/Regents/earthsci/units/ weathering/weathering.cfm found on 1-3-07 Frost action can be quite detrimental to pavement Taken from http://www.uky.edu/AS/Geology/ howell/goodies/elearning/module07swf.swf on 1/7/08
Another Example of Physical Weathering
When gravity causes a rock to fall causing the rock to break.
Takenfrom http://images.google.com/imgres?imgurl=http://humanities.cqu.edu.au/geography/GEOG11023/images/BlockyScreeSlope.jpg&imgrefurl=http://humanities.cqu.edu.au/geography/GEOG11023/Landforms.htm&h=480&w=640&sz=71&hl=en&start=2&tbnid=Oaaqc6AbsMqCBM:&tbnh=103&tbnw=137&prev=/images%3Fq%3Dweathering%2Band%2Berosion%26gbv%3D2%26svnum%3D10%26hl%3Den on 1/7/08
Another Example of Physical Weathering
When flowing water breaks down rocks into rounded sediments.
Taken from http://www.yenacupuncture.com/water%20rocks.jpg on 8/13/08
Chemical Weathering- rocks are
broken and the rock material
itself is also changed.
Taken from http://www.endex.com/gf/buildings/liberty/solgallery/kj053.jpg on 1/5/07 >>> The Statue of Liberty <<<
Example of Chemical Weathering
Oxidation- oxygen from the air combines with the minerals of the rock to form oxides.
http://gpc.edu/~pgore/geology/geo101/weather.htm found 1-5-06
Another Example of Chemical Weathering
Carbonation- water containing carbonic acid dissolves the minerals of the rock.
Taken from http://www.devsys.co.uk/Album/Places%20of%20Interest/limestone%20caves.jpgon 1/13/08
Another Example of Chemical Weathering
Hydration- minerals such as mica and feldspar absorb water, weaken, and crumble to form clay.
Hydration animation Taken from on http://uregina.ca/~sauchyn/geog323/275.jpg 8/13/08
Climate Effects Of Weathering
Physical weathering dominates in cold and moist climates, such as Canada and N e w York State
Taken from http://www.blueplanetbiomes.org/climate.htm on 1/3/07
Chemical weathering dominates in warm and humid climates such as Florida or a Rain Forest. 1/3/07 Taken from: http://www.blueplanetbiomes.org/climate.htm Generally, the more moisture, the more weathering that takes place. Weathering Review
Explain how particle size and hardness effect rate of weathering
a.) Relationship between particle size and amount of weathering
The smaller the material, the faster the rate of weathering. This is because of a greater surface area on the smaller material that exposes more of it to weathering agents. This type of relation ship is described as inverse.
Particle size Rate of weathering Taken from on http://www.catskillhouse.us/blog/files/paulthurst41_Jotul_F100_with_kindling.jpg 8/13/08 Kindling
b.) Relationship between hardness and amount of weathering
Harder minerals have a slower rate of weathering while softer minerals weather much faster. A greater hardness of a particular mineral is determined by its chemical structure and composition which provides greater resistance to weathering. The relationship between hardness and weathering is an inverse relationship.
Hardness Rate of weathering
The Dirt on Soil Soil slides modified from work done by Devon M., Macy T., Cody G., Cory H., Will M. and Cory W. www.island2000.org.uk 1/7/08 Objective #4: Describe how soil is formed, the different types and how it can be conserved.
Let’s start off with some facts about soil!
Soil Makes up the outermost layer of our planet.
Roots hold the soil together to prevent erosion
Topsoil is the most productive soil layer
Natural processes can take more than 500 years to produce an inch of topsoil
An average soil sample is 45% minerals, 25% water, 25% air and 5% organic matter.
http://www.epa.gov/gmpo/edresources/soil.html on 1/7/08
Soil Formation Soil formation Is the production of soil, particles of rocks, and minerals, and organic matter. The formation of soil happens over a very long period of time. It can take up to 1000 years. Soil is formed from the weathering of rocks and minerals. Rocks from the surface go through a process of weathering and break down into smaller pieces. From there it is mixed with other organic matter, and over time creates a thin layer of soil. http://library.thinkquest.org/J003195F/soil.htm on 1/7/08 http://images.encarta.msn.com/xrefmedia/aencmed/targets/illus/ilt/T045308A.gif on1/7/08
S oil C omposition Soils are a mixture of different things; rocks, minerals, and dead, decaying plants and animals. Soil can be very different from one location to another, but generally consists of organic and inorganic materials, water and air. www.macaulay.ac.uk on 1/8/08
Climate is the most important factor in determination of soil type, soils formed from parent materials of different materials will have different chemical composition.
http://images.google.com/images?hl=en&q=soil+composition&btnG=Search+Images&gbv=2 on 1/7/08 A diagram of what soil is made of.
Good soil is more valuable than gold because good soil enables lots of production for farmers to support the earths growing population.
Stages of Soil Formation
There are four stages of soil formation Shown to the right.
The Stages of Soil Formation begins at stage one. Stage one has a very thin layer of soil and a thick layer of rock. As The formation progresses the rock layers become thinner because they break apart, and as they break off the pieces become smaller and turn into dirt which in time makes the dirt layer thicker and the rock layer thinner. Also as the formation progresses plants begin to grow on top of the dirt.
Stage One Stage Two Stage Three Stage Four http://library.thinkquest.org/J003195F/soil.htm 1/8/08
Unit of soil classification, including the characteristics of the soil, composition, porosity, permeability, structure, and the ability to support life.
www.jupiterimages.com 1/7/08 www.nap.edu/staff/mjensen/iacrl/overview.htm 1/7/08 A plowed field, that is able to support life. A field that is planted with corn and is Supporting the corn for a crop.
S O I L H O R I Z O N S
A Soil horizon is a specific layer in the soil which measures parallel to the soil surface and possess physical characteristics which differ from the layers above and beneath
here There are many soil horizons the first is the O Horizon . This is made up of leaf litter and humus. A Horizon this is the second horizon it is called topsoil. It is made of humus and mineral particles. E Horizon this is the third horizon. This layer is made up of mostly sand and silt. B Horizon this is the fourth horizon. The B horizon contains clay and mineral deposits that it receives from the layers above when water drips through. C Horizon This is the fifth horizon that is made of slightly broken up bedrock. Plant roots do not penetrate into this layer. R Horizon This is the sixth horizon. This is the bedrock layer. Soil Horizons Diagram http://www.enchantedlearning.com/geology/soil/ 1/8/08
Immature Soil is less developed. It only has one to three layers. Top soil, Partly weathered rock, and unweathered rocks. ( the rock layers in order from top to bottom.)
Dry- Less water. Less vegetation and animals. Poor soil with little organic minerals.
Humid- High in organic matter, not a lot of salt. Better developed. Supports plants and animals.
http://cache.viewimages.com/xc/1277168.jpg?v=1&c=ViewImages&k=2&d=17A4AD9FDB9CF19390335F8FA9CA92A68F94408D73F68A7F9930FDCFC4C15FBB 1/7/08 Animals grazing on rich soil
Different Climates Continued
Bedrock type- Different bedrocks provides different minerals for soil.
Humans- Increase erosion of soil, adds salt and toxic chemicals to soil.
http://www.spusa.org/mindfull/wp-content/uploads/2006/12/basel-action-network.jpg 1/7/08 Humans putting toxins into the soil
Using soil in ways to preserve and protect it.
www.belfastcity.gov.uk on 1/8/08 Planting a garden can give the soil nutrients and the roots can hold it together so that it doesn’t erode away. Why is it important to conserve soil?
Soil conservation is a set of management strategies for prevention of soil being eroded from the earth’s surface or becoming chemically altered by overuse and contaminated.
No-till farming, is considered a kind of conservation tillage system and is sometimes called zero tillage. It is a way of growing crops from year to year without disturbing the soil through tillage. Once called chemical farming, the reference was subdued in order to promote the idea of no-till being more natural. It is becoming more common as researchers study its effects and farmers uncover its economic benefits
Pic found at http://en.wikipedia.org/wiki/No-till_farming on 1/7/08 Info found at http://en.wikipedia.org/wiki/Soil_conservation on 1/7/08 No-tillage farming
Objective # 5
What Is Erosion?
Erosion and sediment slides modified from work done by Nate K., Rachel P., Morgan M., Brittany W., Paige G., Scott T., Anthony S., Jacob W., Moria S., Emma G., Elizabeth B., Madison M., Kaleb B. and Frank B.
Erosion is the transportation of rock, soil, and minerals from one place to another .
The primary force that drives erosion is gravity .
Bank erosion started by four wheeler all-terrain vehicles, Yauhanna, South Carolina Taken from http:// en.wikipedia.org/wiki/Erosion on 1.3.08 Displacement is another way to say movement of a sediment. Displacement of sediments from their source to another location is the major evidence for erosion.
Explain the difference between residual and transported sediments Objective # 6
Two characteristics that can tell you were a sediment came from are mineral composition of sediments and organic remains within the sediment.
If you find lime stone, you know it probably came from around here in the Thousand Islands region. If you find red sand around here, you know it probably didn’t come from here.
Residual sediment- material that remains at the location of the weathering
Transported sediments- erosional product that has been moved to another location
The sand is a transported sediment from the bottom of the ocean.
1/5/07 Taken from www.hawaiiweb.com /.../ waianapanapa_park.html Stream animation
Between residual sediments and transported sediments , the transported sediment is more common in NYS.
This picture was taken from: http://en.wikipedia.org/wiki/Pebble on 1-5-07
Objective # 7
Tell the different characteristics of minerals moved by running water, wind and ice.
Taken from http://www.mfr.usmc.mil/4thmaw/mag46/detb/HMM764/Deployment/PhotoSandstorm.htm on 1-4-07 Sandstorm in Iraq
Properties of Transported Materials
*Transporting agents- actions that affect erosion and move sediments from one place to another.
Taken From: http://www.freenaturepictures.com/pictures/sunny-forest-stream-2.html on 1-5-07 A stream flowing through the forest in the sunlight. In Wyoming.
There are three basic transporting agents that are going to be mentioned: water, wind and ice. Each transporting agent leaves distinctive marks or characteristics on the material that it moved. Therefore, it is often possible to determine what eroding force moved a particular sediment.
Taken from: http://www.environment-agency.gov.uk/commondata/103196/1457133?referrer=/subjects/waterres/1014767/ on 1-5-07 This is a tributary of the River Wey that has been dry during the summer of 2006 due to the drought.
* Water tends to smooth and round rock particles
Taken from: http://education.usgs.gov/schoolyard/RockDescription.html on 1-5-07 These are rocks that have been smoothed by water
* Wind tends to leave sediments pitted or “frosted” as a result of abrasion during their travel.
Taken from: http://www.wildnatureimages.com/sand_dune_pictures.htm on 1-5-07 Sand dunes at Death Valley National park in California
* Glacial products often have surface scratches due to being pushed and scraped by the ice .
Taken from: http://education.usgs.gov/schoolyard/glacialstriations.html on 1-8-07 Rock surface after the glacier that once sat on this area melted. Located in Glacier National Park, Montana
Objective # 8
Give characteristics of the 5 factors that transport sediments.
Factors affecting transportation
The five main factors affecting transportation are: gravity, water, wind, ice, and human activity.
http://www.thegardenhelper.com/102920.JPG on 1/5/07
Gravity is the main force behind all transporting systems. Gravity may also act alone. An example is when a loose rock on the side of a slope breaks away and falls down the hill.
We got these pictures from http://seis.natsci.csulb.edu/bperry/Mass%20Wasting/Slides.htm 1/5/07
Running water is a predominant agent of erosion. As streams down cut the underlying bedrock, they initially carve V- shaped valleys.
http://www.geography4kids.com/files/land_erosion.html on 1/9/08 1.7.08 found at http://www.mrsciguy.com/sciimages/vshaped.gif
Strong winds and storms can erode sediments leaving them with a pitted or “frosted” appearance from the abrasion. Wind erosion can also form a variety of unique formations such as dunes. Light winds move only smaller sediments, and strong winds may move heavier and larger particles such as sand.
Taken From: http://www.phototravels.net/egypt/egypt-v/egypt-v-072.html on 1/5/07 1.7.08 Photo found at http://www.disc.wisc.edu/pubs/images/wind.jpg
The steeper the valley of a mountain the faster a glacier will move and the more larger sized materials that it can carry. Glaciers can transport the largest sized sediments, boulders. Material moved by glaciers often have scratched surfaces.
http://www.hickerphoto.com/iceberg-photos-4630-pictures.htm on 1/6/07
Humans have greatly influenced the process of land erosion
w/ a number of activities such as:
Highway and industrial construction,
Destruction of forests (fire, tree cutting, etc.)
Strip mining and
Poor landfill products, etc.
Displacement of rocks and soil increases land erosion.
http:// www.gradingandexcavation .com/gx_0611_flexibility.html found 1/8/07 . Photo found at 1.8.08 http://www.uec-utah.org/position/salvageTS-cedarcityrd-DIXIE.jpg
Mass movement or mass wasting
This occurs when soil and/or pieces of rock are pulled down slope. Mass movement may be rapid like a landslide or slow like a soil creep.
trunks indicate a
http://gpc.edu/~pgore/geology/geo101/masswasting.html 0n 1/5/07 http://gpc.edu/~pgore/geology/geo101/masswasting.html on 1/5/07
Objective #9 Describe differences between straight and meandering stream channels and the 3 factors related to stream velocity.
Stream slides modified from work done by Kevin B. and Pat M.
Stream velocity and size of sediments carried by stream.
As the velocity of the stream increases, the size of the particles that can be moved by the stream increases .
This is a direct relationship.
Fast moving streams can carry a variety of sized particles.
Streams can carry dissolved material in suspension , small particles in suspension such as colloids, clay, silt, and sand, and larger particles like pebbles, cobbles, and boulders by rolling, bouncing or dragging along the stream floor. Animation
A graph comparing stream velocities with particle size in in the ESRT on p. 6 .
As the stream slows down, the size of the particles that it can carry decrease . The smaller sized particles will be dropped or deposited first.
Friction- force found at the contact of two surfaces that offers resistance to motion often producing heat or another energy.
The greater the amount of friction a stream has with its bed or channel, the slower the water will flow.
The most efficient channel is one that is smooth and has a semicircular shape.
Velocity Differences Within a Stream Channel http://www.chemistry.org/portal/a/c/s/1/wondernetdisplay.html?DOC=wondernet%5Cwhatsup%5Cfriction%5Cpencil.html 1/5/07
Taken from http:// www.paleocurrents.com/castle_rock/docs/meandering_river.htm on 1-03-07 Taken from clip art on 1-4-07 Stream Diagrams Erosion point Deposition point The stream is fastest at this point
Meandering-curving pattern of a river due to erosion and deposition.
The fastest flowing water in a straight section of a stream is in the center just below the surface where friction is least.
In a meandering stream the fastest water is on the outside of the curve or meander, so that is where erosion is the greatest .
Discharge- volume of water in the stream at any given location during a specific amount of time
The greater the stream discharge, the greater the average stream velocity. This is a direct relationship. In the spring time, both of these variables are usually greater due to snow melt and greater runoff.
More discharge Less discharge Taken from clip art 1-4-07
3 factors related to Stream Velocity
Slope of the Stream Bed
3) Size of Particles carried by the stream increasing Discharge Stream Velocity increasing Slope Stream Velocity increasing Particle Size Stream Velocity
Objective #10 Describe ocean waves, the parts of a wave and what creates a wave. Ocean slides modified from work done by Andrew G., Jeremiah S., Mike H. and Jamie S.
Most of waves on the oceans surface are caused by wind.
http://fly.hiwaay.net/~mhongser/art/waves.htm on 1/7/08
The length the wind blows across in a given direction will produce the wave length.
http://en.wikipedia.org/wiki/Ocean_surface_wave on 1/7/08
The distance of the wave expanded is known as the Fetch.
The less objects blocking the wind will cause a greater fetch . Trees or buildings may block the wind causing a smaller fetch St. Lawrence river From Cape Vincent NY, original photo by Jamie St.Onge
A great enough one may generate a tsunami.
Tsunamis: seismic sea wave commonly referred to as a tidal wave although its not caused by tides.
Waves can also be produced by submarine earthquakes, landslides, or underwater volcanoes. http://www.ess.washington.edu/tsunami/index.html 1/7/08 The last major tsunamis happened on 26 Dec 2004, 00:58:53 UTC (7:58:53 am local time), when a magnitude 9.0 earthquake occurred off the west coast of northern Sumatra, Indonesia.
Wavelength- distance between two successive wave crest.
Trough- bottom part of a wave.
Crest- top of a wave.
As waves move trough the water, the water particles rise and fall on a circular paths with little forward moment until the wave gets close to shore. When a wave reaches shallow water along the shore, friction causes the bottom of the wave to move more slowly than the crest, which falls over on the shore forming a breaker resulting in the foaming water called surf .
A = At deep water. B = At shallow water. 1 = Progression of wave 2 = Crest 3 = Trough From http://upload.wikimedia.org/wikipedia/commons/1/11/Wave_motion-i18n.png on 1/4/08 wavelength crest Trough
OBJECTIVE #11 Know the difference between beach and shoreline vocabulary: jetties, groins, refraction and longshore current
Coastal Processes (Cont.)
Longshore current- Current moving sediments parallel to the coastline.
As waves strike the shoreline at an angle they form a longshore current. The sands transported by these currents are deposited farther along the coast. May costal communities build groins and jetties to stop erosion caused by longshore currents.
Shoreline of lake Ontario from Tibbets Point Lighthouse. Original Photo
Beach- shoreline region of deposited particles may contain sand, gravel, pebble, cobble and/or boulders.
Beaches vary in shape size and composition. Beaches also vary in color depending upon the parent material forming the sand.
St. Lawrence river from Cape Vincent NY, Original Photo
As a line of waves approaches the shore it tends to bend and strike the shore “head on”. The force of the waves striking the headlands breaks the rocks straightening the coastline. Erosion and deposition are constantly changing coastlines. Several meters of material can be moved by one violent storm.
From http://upload.wikimedia.org/wikipedia/commons/3/37/Shallow_water_waves.gif on 1/7/08
http://www.south-seas-adventures.com/Gallery/South_Pacific_Beaches_1/image001.htm#description (1/3/07) When a wave reaches shallow water along the shore, FRICTION causes the bottom of the wave to move more slowly than the CREST witch falls over on the shore forming a breaker resulting in the foaming water called SURF . Friction is whatever gets in the way of a smooth and uninterrupted flow of events www.glossika.com/articles/re-energize_your_business.php (1/3/07)
The water that hits shore is pulled back by GRAVITY and this backwash rolls beach materials toward the ocean. If the waves strike the shoreline at an angle, they form a LONGSHORE current in the SURF ZONE witch moves sediment parallel to the coast. Beach sand is transported by longshore currents are deposited farther along the Cost. http://en.wikipedia.org/wiki/Image:Longshoredrift.gif (1/5/07)
Coastal communities may build walls ( GROINS ) perpendicular to the shore to prevent this removal of sand. Rock barriers ( JETTIES ) are also built on both sides of a harbor entrance to slow sedimentation which would clog the entrance to the harbor. JETTIES http://texascoastgeology.com/passes/Packery%20jetties%207-22-05.jpg (1/8/07) GROINS http://www.msstate.edu/dept/geosciences/CT/TIG/WEBSITES/RESEARCH/Gregory_Harris/shorel_jpg.jpg (1/8/07)
Objective #12 What is deposition? Describe 4 factors that affect deposition and how both vertical and horizontal sorting occur. Deposition slides modified from work done by Korrey R., Tiffany B., Anthony B., Pete L., Scott H. and Jessica W.
Deposition Deposition is the process by which sediments carried by a transporting agent are dropped from the medium . Deposition is also called sedimentation. Final deposition occurs at the end of a stream and losses velocity upon entering a larger body of water. Ex. Lakes, oceans, ect . http://physics.uwstout.edu/geo/sect5.htm January, 4 th , 2007 Picture of a sandbar. It shows the sand and rocks and sand on the shallow part of a lake, to show the dropping off of rocks and minerals.
Four Factors Affecting Deposition Particle size Particle shape Particle density http://pds-rings.seti.org/saturn/artwork/plate_07.gif 1/7/08 http://www.vacet.org/gallery/images_video/particle-heightfield_sm.png 1/7/08 www.rsc.org/ejga/JM/2006/b513095f-ga.gif 1/7/08 Stream Velocity
As a stream’s velocity decreases, larger particles settle out first as gravity pulls them down. Smaller sediments settle out more slowly . As long as the water moves lightly the smallest particles called colloids may remain in suspension.
http://regentsprep.org/Regents/earthsci/ January 10th 2007
Spherical shape sediments are deposited more quickly than flatter disk-shipped particles. This is due to greater resistance on the flatter particle that causes it to drop more slowly .
This is a picture of a diagram that explains that the rounder the particle, the faster it settles, but the flatter the particle, the slower it settles. http://regentsprep.org/Regents/earthsci/units/weathering/particleshape.gif January 10 th 2007
A high density particle will settle faster than a low density particle because the high density sediment is heavier .
This is a picture of lead. Lead is a very high density type of rock and will settle quicker to the bottom of a body of water than a rock made out of feldspar. http://www.galleries.com/minerals/elements/lead/lead.jpg January 10 th , 2007
Sediments being carried by a stream generally do not move at the same velocity as the water. Most particles tend to move at a speed slower than the speed of the moving water. The lone exception may be colloid particles in suspension which can move along at the same speed as the water.
http://www.frw.ca/albums/Correcting-Stormwater-Mistakes/Serious_Erosion_of_Morningside_Stream_below_Malvern_Outfall_2998_IMG0061.jpg January 10 th , 2007 Picture of a stream. It shows how the velocity of the stream slows down after going down a hill.
Horizontal Sorting When a body of water loses velocity, and particles with greater weight and density settle first it is called Horizontal Sorting. This sorts sediments according to size along the river bed. http://www.mrsciguy.com/sciimages/horizontal.jpg January 8th, 2007 Picture of Larger rocks and sediments like boulders and cobbles, being dropped off before the smaller rocks and sediments such as sand, salt and clay. Animation
Vertical Sorting Vertical Sorting (Graded Bedding) is deposition is very rapid and different sorting occurs. The particles are sorted on top of one another alternating bands of large to small sediments. http://www.geog.uu.nl/fg/mkleinhans/publicat/conf/gbr5/kleinhans5.htm January 10 th , 2007 Vertical Sorting separated the sand & pebbles into bands. http://regentsprep.org/Regents/earthsci/ January 10th 2007
Deposition made by gravity acting alone or by glacial ice is unsorted since sediments of all sizes, shapes and densities are deposited together. Glacial debris deposited by melt waters will show characteristics similar to stream deposits.
http://www.homepage.montana.edu/~geol445/hyperglac/terminal3.jpg January 9th, 2007 Picture of glacier and a mountain that deposits rocks, sand, and sediments at the bottom.
Wind deposited sediments are most common in regions with arid or dry climates and along coastlines where sand dunes may form. Although the range of particle sizes deposited by the wind is smaller than those of other agents of erosion, the sediments still show the characteristic of sorting . Changes in direction of the wind may result in the layers or beds of sediment being deposited at different angles called cross bedding . In areas with strong winds, rock formations, buildings and other structures may show the effects of sand blasting.
Picture of a sand dune. This shows how the wind blows and drops off the sand in another location. http://www.indiana.edu/~g103/G103/Week8/week8.html on 1/6/07
Crossbedding Changes in direction of the wind that results in the layers or beds of sediment being deposited at different angles is called Crossbedding. http://epod.usra.edu/archive/epodviewer.php3?oid=131328 January 10 th 2007 Picture of part of the Bright Angel Trail in the Grand Canyon. The angled strips are caused by wind blowing sand towards the rock and the sand (sandblasting) causes the rock to weather.
Objective 13: What is a glacier, how are they formed and how do they move?
Objective 14: Contrast the 2 types of glaciers and their characteristics.
Objective 15: Describe the recent history of glaciers in NYS and explain the glacial vocabulary terms.
Glacier slides modified from work done by Skyler B., Carissa C., Amber D., Jessica H., Robert F. and Robert K. Glaciers A Glacier in Canada http://www.nsf.gov/od/lpa/news/02/images/glacier_hi.jpg 1/3/08 Glacial Glossary link
What exactly is A Glacier?
It’s a huge mass of ice slowly flowing over a land mass, formed from compacted snow in an area where snow accumulation exceeds melting and sublimation.
Glaciers are found at high altitudes and at high latitudes also known as high mountains. http://images.google.com/imgres?imgurl=http://imagecache2.allposters.com/images/pic/NIM/KC356~Matunuska-Glacier-Alaska-Posters.jpg&imgrefurl=http://www.allposters.com/-sp/Matunuska-Glacier-Alaska-Posters_i310875_.htm&h=450&w=320&sz=26&hl=en&start=10&tbnid=vW1tM6L6yZi6PM:&tbnh=127&tbnw=90&prev=/images%3Fq%3DGlacier%26gbv%3D2%26svnum%3D10%26hl%3Den on January 4, 2008 Where are Glaciers found? It must be cold!
Glaciers and Icebergs are different because an iceberg is on water and a glacier is on land. When a glacier gets closer to the water a piece will break off and that is what we call an iceberg.
The Difference between an Iceberg and a Glacier http://images.google.com/images?hl=en&q=Glacier&gbv=2 on Jan. 4,2008 http://images.google.com/images?gbv=2&svnum=10&hl=en&q=iceberg on Jan.4,2008
Ice flows because of the gravity of motion pulling it slowly from its center of accumulation or snow field.
What causes Ice to Flow?
Glacier found in a mountain valley.
How do I know if it is an alpine glacier?
Well an Alpine Glacier will be between two mountains in the dip or valley and it will be a long sheet of ice or snow.
Alpine Glaciers http://images.google.com/images?hl=en&q=alpine+glacier&gbv=2 on Jan,2008
Alpine Glaciers carve U-shaped valleys.
Alpine Glaciers form cirques, horns, tarns & arétes.
They are large ice sheets like those found in Antarctica and Greenland.
As they move out from their center of accumulation, the weight of the thick ice tends to depress, scour and round the land surface. As glaciers move, they carry, push and drag enormous amounts of glacial till (unsorted sediment ). The sediment ranges in size from large boulders to the finest clay. http://www.uwsp.edu/geo/faculty/ritter/images/lithosphere/glacial/glacier_Ellesmere_GSC_small.jpg 1/4/08
Sediments frozen in the bottom of the glacier gouge out parallel striations or grooves in the bedrock over which the glacier passes. These striations or grooves indicate the direction of moving the glacier. In new York state, rounding of rock surfaces and glacial striations in both the Catskills and Adirondacks mountains show that glaciers at least one mile deep covered NYS http://www.ux1.eiu.edu/~cfjps/1300/striae2.JPG 1/16/08 Parallel Striations
Striations can be observed at about 4000 feet elevation on Hunter Mountain in the Catskills. They show that the ice was a minimum of a mile thick over this part of New York State. Thomas McGuire, Cave Creek, AZ Author, Amsco School Publications, NY
The melting of glacial ice randomly drops large boulders called erratics that are left scattered over the landscape. Sometimes the rock type of erratics can be distinctive enough to let scientists trace the rock to its source and therefore give evidence of the direction of ice flow.
Occasionally an erratic is left perched on top of smaller boulders after many years of erosion. This perched erratic is at North Salem in Westchester County. Thomas McGuire, Cave Creek, AZ Author, Amsco School Publications, NY
Round bottomed valleys carved as a result of glaciers.
Glacial hill shaped like back of spoon.
www.geography-site.co.uk on 1/7/08 oz.plymouth.edu on 1/7/08
Hundreds of drumlins lie between Rochester and Syracuse, NY. This is part of a drumlin field east of Rochester. Note that the trailing ends of the hills are the southern slopes. The north slopes are usually more blunt. Thomas McGuire, Cave Creek, AZ Author, Amsco School Publications, NY
Large ridge of glacial till marking the farthest advance of glacial ice.
www.swisseduc.ch on 1/7/08 3dparks.wr.usgs.gov on 1/7/08
Horizontal layers of sorted glacial material deposited in front of the glacier by the melt waters of the glacier.
www.isgs.uiuc.edu on 1/7/08 pubs.usgs.gov on 1/7/08
Kettle hole filled with water.
piru.alexandria.ucsb.edu on 1/7/08
The Finger Lakes of Western New York State were excavated as U-shaped valleys by the glaciers advancing to the south. Moraines dammed the former south flowing outlet rivers. Thomas McGuire, Cave Creek, AZ Author, Amsco School Publications, NY
Superimposed layers of weathered till give scientists and other observers that there have been several glacial periods in New York State and throughout the USA in the Pleistocene Epoch.
We have experienced many glacial and interglacial periods
We are shown to be currently in an interglacial period
The average global temperatures over the past 1000,000 years. Thomas McGuire, Cave Creek, AZ Author, Amsco School Publications, NY
Ice coverage of North America approximately 21,000 years ago Thomas McGuire, Cave Creek, AZ Author, Amsco School Publications, NY
The only part of New York that was clearly never covered by glaciers is Allegheny State Park in Western New York State.
Long Island was built by glacial sediment. Thomas McGuire, Cave Creek, AZ Author, Amsco School Publications, NY
The Ronkonkoma Moraine dips below sea level at Montauk Point. This is New York’s most eastern landfall. Note the boulders washed out of the moraine. Thomas McGuire, Cave Creek, AZ Author, Amsco School Publications, NY
Glacial ice ages in New York State as well as the rest of the world, has not only altered the landscapes, but it has caused the migration of animals and changes in the animal and plant communities [Hint: the Ice Age]
Most soils in New York State are thin, rocky, and poorly developed. These poor soils are made of weathered glacial till and are found all over NYS supporting the idea that glaciers have covered almost all of NYS
“ I think I’m gonna be sick…, this Ice Age thing stinks… Melt already!” Found 1-12-07
As glaciers grew and the ice advanced , sea level dropped because more water was being frozen as ice. Fossil and geologic evidence from the Pleistocene epoch indicates that periodic changes in sea level coincide with the advancing and retreating of ice sheets.
Long Island is an example of this
The ice ages left behind an important geological resource for the NYS economy. This resource is sorted and layered deposits of gravel and sand
Long Island Found 1-12-07
Also: Frink Park in Clayton has striations within the rocks near the shore. These were caused by glaciers because a long time ago this part of New York was covered in glacial ice.
More History of Glaciers in New York
Glacial ice can also give clues to environmental conditions of the past. Scientists can drill ice cores from deep into a glacier. Ice deep within the glaciers was formed hundreds of thousands of years ago.
More About Glacial Ice http://tvl1.geo.uc.edu/ice/Image/pretty/467-4.html on 1/12/07
This ice may contain trapped air, dust or pollen from the distant past that may also give indications of past environmental conditions.
More About Glacial Ice Continued http://tvl1.geo.uc.edu/ice/Image/pretty/hang.html 0n 1/12/07
Objective #16 Compare landscape characteristics for plains, plateaus, and mountains Landscape slides made by Eric H-W., Sara A. and Mark W. in January 2007. Modified by Mr. O.
D. Landscape Characteristics I. Landscape Regions Distinctive landscape regions can be identified by sets of landscape characteristics that seem to occur together . These characteristics help classify landscapes into mountains , plateaus or plains . relief- difference between the highest elevation and the lowest http://www.picturesofplaces.com Picture of grand canyon
Relief & Elevation Rock Layers High relief, high elevation deformed rock structure Moderate relief, high elevation horizontal rock structure Low relief, low elevation horizontal rock layers Mountains Plateaus Plains http:// www.freenaturepictures.com
Generally landscape regions have well-defined boundaries separated by natural boundaries such as mountains and bodies of water. The United States and New York State have a number of different landscape regions. The landscape regions for NYS are found on ESRT p. 2. http:// www.wvhighlands.org
Objective #17 Describe how Geological Forces, Climate, Bedrock type, Time and Human Activities influence the development of landscapes
II. Factors influencing landscape development
A .Geologic Forces
The two major forces which oppose each other in the formation of landscapes are uplifting and leveling . They are also called constructional and destructional forces.
Uplifting- to build mountains, enlarge continents and increase the elevation of some landscapes.
Leveling- The processes of weathering/erosion and subsidence which causes leveling.
The present conditions of a landscape are determined by which of these two forces are currently dominant and were dominant in the recent past.
1). Humid climates ( humid – wet ) There is a greater amount of weathering ,erosion and deposition causing rounded hills and less steep slopes. Streams are permanent, flowing into rivers and eventually larger bodies of waters therefore, weathered sediment is often are transported great distances from the source of weathering. http://www.travel-himalayas.com/himalayas-pictures/
Arid ( dry)
Arid regions have less water erosion, so therefore hill slopes are generally more steep and angular. Streams are usually intermittent ( seasonal) and water is usually collected in basins in the region so weathered sediment is often found from the source of the weathering.
The angular and jagged landscapes of the Southwest such as at Monument Valley in Arizona, indicate an area that was never covered by continental glaciers. Thomas McGuire, Cave Creek, AZ Author, Amsco School Publications, NY
C) Bedrock effect on Landscape Development
Rock resistance – is the ability of different rock types to resist the forces and erosion.
When bedrock with varying degrees of rock resistance occur together, the softer bedrock is weathered and eroded at a faster rate than the more resistant rock. This results in an irregular landscape. The softer, the weaker less resistant or incompetent rocks usually result in valleys and other low level areas.
Meandering streams thick soil horizons and deep layering characterize areas with weak rocks. Harder, more resistant or competent rocks often are responsible for plateaus , mountains and escarpments. These areas often have slow rates of change. Escarpment- which is a steep slope separating two gently sloping surfaces.
Volcanic cones & young Domes Radial Drainage
Domes the have eroded Annular Drainage
Parallel folds and/or faults Trellis Drainage
Flat area with consistent bedrock Dendritic Drainage
Type of Drainage Pattern
Rectangular Drainage A. B. C. D. Trellis Drainage Dendritic Drainage Radial Drainage
Older landscapes generally show more effects of weathering and erosion than younger landscapes.
1) Negative Affects by Humans on Landscapes. Ex. Both intentional and unintentional technological oversights have brought about planned consequences that have destroyed or reduced the quality of life in many landscapes regions.
Positive Affects by Humans On Landscape Ex Humans have begun to intervene in the widespread destruction, through the efforts of indivduals, community groups, in conservation clubs.