GRADE DISTRIBUTION. The Great Plains OVERVIEW. Great Plains and Prairies. The Great Plains 4/27/2015 DATES TO REMEMBER. and Prairies Part 1

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1 GRADE DISTRIBUTION EXAM II results: 3A+ (highest score = 04) 7A 8B 4C D 0F 50% of your grade is in. 25% Exam III (final) 25% Required landscape exercise. P L U S Exam Scoring Numbers st = short answers 2 nd = essays 3 rd = extra credit definitions 4 th = extra credit assignment 5 th = total score Any of the extra credit options on the syllabus: Research paper on a preapproved topic; Geography in the News collection of articles. DATES TO REMEMBER COURSE EVALATION PERIOD NOW OPEN Go to Check your Hunter account for notice from the Dean of Students. Can do it on line or on a SmartPhone May : Last day to hand in REQUIRED LANDSCAPE EXERCISE without penalty and last day to hand in preapproved extra credit research paper. May 4: Last class lecture WEDNESDAY, May 20: Exam III: The Final Exam From 3 to 5 PM << note different day/time from class Same format as exams I and II. Last day to hand in Exam III extra credit exercise and Geography in the News extra credit option. Regional Landscapes of the United States and Canada and Prairies Part Prof. Anthony Grande Great Plains and Prairies When you think about this region, what images come into your mind? Boring landscape Flat grasslands Small towns Cattle Cowboys & Indians Straight roads Blizzards Windy area Wheat farms AFG Big sky country. Amber waves of grain. 5 OVERVIEW Ch. 9 in American Landscape; review Ch. 2, 7. Sect. 6 in Historical Atlas Flat to rolling landscape with some irregularities. Experiences extreme and violent weather. Has a rainwater deficiency; dependent on groundwater. Historically, an area of many negative misconceptions, esp. as a place to live and farm and about the Indian occupants. Good food source: hunting to grazing to farming. Characterized by a rectangular land division system. East-west transportation routes pass through it. Has been affected by farm management decisions. Part of both the Louisiana Purchase and Spanish North America not uniform culturally. 6

2 Plains vs. Prairies: What s the difference? Great Plains at Night Plains is a topographic term signifying expansive and relatively flat land. Prairie is a vegetation unit that refers to a variety of grasses. Most of the Great Plains was originally covered by prairie. Prairie covered plains. 7 What do you notice about the pattern and density of the dots within the boxes? 8 Great Plains at Night 9 Area of minimal topographic relief. Situated between the Interior Lowlands (east) and the Rocky Mts. (west) and from Canada s northern coniferous forest (north) to the Mexican border (south). Layers of sedimentary rock are very thick and slope toward the Mississippi River. Some layers are porous and contain great water supplies. WEST EAST Gently increases in elevation from east to west ( ft.) Area closest to the Rocky Mts. is called the High Plains. 0 Physiography AREAS of RUGGED TERRAIN INCLUDE: Cyprus Hills (Sask) Badlands (ND,SD) Blacks Hills (SD) Sand Hills (Neb) Edwards Plateau (TX) Note the parallel, E-W alignment of the rivers. The Llano Estacado or Staked Plains is the flattest, most featureless section of the Great Plains. Unusual Terrain Features Badlands erosional landscape of deep gullies carved into soft rock by running water; barren or sparsely vegetated. Badlands NP is in South Dakota. Braided stream a drainage pattern created by slow-moving water carrying a large sediment load; characterized by numerous shallow, shifting channels. The Platte River of Nebraska is a much used example. 2 2

3 Unusual Terrain Features Sand hills grass-covered, stabilized sand dunes. The most famous in the US is the Sand Hills region of Nebraska. Buttes features created from the erosion of layers of sedimentary material; used as landmarks. Wagon Mound is in New Mexico. Geologic domes an area of metamorphic rock uplift created by deep volcanism; surrounded by sedimentary rock cuestas. The Black Hills straddle the South Dakota/ Wyoming border. 3 Black Hills and Vicinity 4 CLIMATE In the rain shadow of the Rockies. D R Y Rocky Mts. Great Plains PHYSICAL CONDITIONS Precipitation Natural Vegetation Forest Tall grass area extends into the Midwest as the prairie peninsula and is part of the agricultural core s Corn Belt. It has a semi-arid climate with cold winters and snow (BSk) in the north and dry subtropical conditions in the south (BSh). Precipitation decreases from east to west. It occurs along the frontal zones of air west east masses inch line 40 inch line 6 VEGETATION Pioneer Sod House Grasses predominate. Taller and more dense in the eastern plains Shorter and sparser in the western plains Intricate root systems Add decayed organic matter to soil Short grass prairie Very difficult to plow Can be cut into blocks; it was used as construction material (sod houses) Trees are found along rivers and in areas where water is close to the surface

4 SOILS Chief soil type is Mollisols: forms under grasses not forests. Characterized by a thick surface layer (up to 5 ft) and high organic content that comes from the grasses dense root systems. Excellent for grain production. AIR MASSES are in the zone of conflict between major air masses. Greatest difference in the temperature of the air masses is during spring and autumn. Thunderstorms, blizzards, high winds and tornadoes are common Area of Extreme Weather Great seasonal swings of temperature. - Range is from below 0 F to over 00 F Blizzards Heavy snow + high wind + intense cold Can last for several days Can cause whiteouts that limit visibility Windy environment - Increases rate of evapotranspiration (desiccation) - Experiences some of the highest average wind speeds in North America outside of severe storms. Drought cycles. - Undependable precipitation. 2 Kansas Drought Cycles Precipitation is not dependable: Wide variation from year to year (80% to 20% of average ) with periods of drought. Drought occurs in roughly 20 year cycles. Optimism in good years leads to disaster in dry years. 22 DUST BOWL Dust Bowl: an area on the southern High Plains that experienced major dust storms during the severe drought of the 930 s. Dust storm: when strong winds blow fine particles high into the air and reduce local visibility. Its forward edge is usually marked by a wall of dust. It was immortalized by John Steinbeck s novel, The Grapes of Wrath, which told the story of poor Oklahoma farmers during the Great Depression. 23 Dust Bowl Area Dust clouds reached the east coast. BARE DRY SOIL + WIND = DUST 24 4

5 930s Dust Storms Caused by a combination of natural and human deeds:. Inappropriate deep-plowing techniques. 2. The false belief that rain follows the plow. 3. Several years of drought that contributed to a drying of the exposed topsoil. 4. High winds that picked up the dried soil and carried it away. More Extreme Weather Chinook: a regional wind called the snow melter Occurs in winter as warm dry air descends from Rocky Mts. Gives relief from bitter cold and snow. Thunderstorms with hail - Collision of contrasting air masses - Creates intense local weather conditions Tornadoes - Result of extreme thunderstorm conditions. - Extremely destructive within small areas Tornado Alley Tornado Formation Tornado Alley A vernacular region that refers to parts of the U.S. where tornadoes are most frequent Tornadoes on the Ground Texas Landscapes of Destruction: Aftermath of a Tornado Kansas Iowa ture/ stm wmvfn7y8v8&feature=related dk6h9d6j0 29 Joplin, Missouri 30 5