Final test # 3

 

Geography 102  Section 2 of the course looks at the tectonic processes, hydrologic cycle, soils, and landforming processes

 

Updated 7 March 08 This list is still good

 

Note:

Morning class writes both the regular test 3 and the second lab exam 8am – 10am 20 March.

Evening class writes both the regular test 3 and the second lab exam in the regular class time on 19 March.

 

Morning section:  Last class Monday 17 March

Evening section: Lass class is Monday 17 March. 

 

Ch 14 Internal processes that cause surface deformation of various sorts including mountain building

                  Plate tectonics:

  • Plate Tectonics: meaning of words
  • Lithospheric plates: ride on convection cells that exist in the asthenosphere
  • Earth has a number of plates which move relative to each other
  • Bremerton as being on the North American Plate near the Juan de Fuca plate
  • Continental Drift (Wegener, 1914) – continents ‘match’ in shape, mountain ranges and rock types.
  • Pangaea, a supercontinent about 250 million years ago, supporting evidence
  • Oceanic plates are denser than continental plates
  • Plate Margins; divergent, convergent, transform
  • Divergent (rift): Plates move apart from each other. Mid-ocean ridges dues to seafloor spreading,  rift valleys (Africa, Iceland)
  • Convergent: Plates move towards one another; 3 types

o    continental-continental – collision and mountain building (Himalayas)

o    continental-oceanic – subduction (Cascades, Andes, )

o    oceanic-oceanic – subduction  (Japan, Indonesia, Philippines)

  • Plate tectonics results in various types of orogenesis (mountain building)
  • Transform: Plate slip jerkily past one another. (San Andreas Fault)
  • Hot spots: Plates move over a hot zone in the mantle (Hawaii)
  • Accreted terranes – Formation of west coast mountains in USA, Olympic peninsula.
  • Edges of plates are associated with mountain building, volcanoes, earthquakes depending on the type of interactions.  Ring of fire around the Pacific Ocean.
  • Know location of the Pacific, North American, South American, Eurasian plates,  (see pg 387), the North Atlantic ridge, Sunda trench, Himalayas

·         Resultant landforms: midocean ridges, ocean trenches, volcanoes (shield and composite), faults and earthquakes, rift valleys.

  • Vulcanism – the study of volcanoes!
  • Endogenic process
  • Volcanoes as relative to plate boundaries and hot spots, types of volcanoes, volcanic islands, hydrothermal power, Mt St. Helens.
  • Pyroclastic flow: lava, bombs, ash, hot gas flows, also gas, steam, mudflows from melted glaciers                 
  • Stratovolcanoes (composite volcanoes) viscous lava, gas bubbles are trapped, explosive release    
  • Shield volcanoes: hotter, low silica content, more fluid              
  • Earthquakes: Causes, seismographs, Richter scale, shaking intensity scale, hypocenter, focus, aftershocks, wave types, liquefaction, landslides, prediction. Tsunamis.
  • Earthquake preparedness: earthquake safe house and then water, food, medicines, basic first aid … enough so you can survive comfortably for a week.

·         Folding

·         Rocks: Composed of collection of minerals in crystal form: eg silicon, magnesium, iron, aluminuim

·         Rock types: igneous, sedimentary, metamorphic

·         Crustal deformation: Forces of tension, compression and shear which results in a variety of effects including surface thinning, folds and faults. Normal faults, thrust faults, strike-slip fault. (Faulting as a cause of earthquakes)

 

Ch 13 Introduction to Landform Study 

(We are only looking at a few sections of this chapter, I am combining what you need to know in a presentation on Chapter 14)

  • Earth thought to have formed 4.6 – 4.7 Billion years ago from dust, gases and icy comets
  • Oldest rocks: 4.3 Billion years measured by radioisotope dating
  • Earth’s structure: Densest materials near the center
  • Lithosphere = crust plus upper mantle ‘glide’ on ‘plastic’ asthenosphere
  • Earth’s structure: determined largely from seismic testing, also drilling in crust surface
  • Crust      -oceanic: below oceans/6 miles thick/ as denser than continental crust below land/20 miles thick/
  • Asthenosphere 40-200 mile depth, plastic, convective movement, hot spots
  • Magnetism – magnetic field caused by core rotations. Magnetic reversals average 500,000 years, magnetism as protecting the earth from solar wind and cosmic radiation, movement of magnetic north pole as separate from the geographic north pole
  • Isostatic movements of the crust: change in the amount of continental crust or ice sheet changes, visit them in Norway!

 

  • Landforms: a balance between endogenic processes (largely building processes) and exogenic processes of weathering and erosion

 

  • Rock cycle: igneous, sedimentary, metamorphic
  • Igneous – crystal sizes depend on cooling rates, intrusive, extrusive
  • Sedimentary – water, wind, layers, lithification, fossils, layers of junk, sandstone, coal
  • Metamorphic – heat and pressure changes igneous or sedimentary rocks, eg limestone to marble, shale to slate

 

Ch 15 Weathering and mass wasting

·         Weathering of rock: Chemical and mechanical weatering as a perlude to erosion.

·         Mass wasting

 

Ch 12 Soils

  • Soil components: inorganic, organic, water, air,
  • Soil formation, top down, bottom up
  • Composting at all scales
  • Soil formation factors: climatic (precip, temp, geology, topographic, biological, chronological
  • Soil classification based on horizons,
  • Texture and particle size and shape: Sand, silt, clay, colloids,
  • Acidity ( pH), nutrient attachments to clay, soil structure
  • Soil maps
  • Issues of concern to soil scientists: erosion, nutrient loss, salinization, covering up of valuable soils by houses

 

Erosion (I am going to do a ‘cliff notes’ for the chapters on glaciation, fluvial and aeolian erosion)

·         Erosion as moving weathered material (water, wind and ice)

·         Deposition is when eroded material is left behind

·         Gravity and soil creep, landslides, rockfalls,

·         Agents of erosion: water (fluvial), ice (glacial), wind (aeolian), oceans (coastal processes) , humans

·         Streams and rivers, gentle and steep gradients, deposition and erosion, think of Theler

·         Humans erosion and deposition: agriculture, construction and forestry- can increase erosion by wind and water.

·         Glaciers: act to rearrange loose material on earth and also carve anything from scratches to deep U-shaped channels hundreds of feet deep.  Glaciation is not something that we think about much but they have formed some of America’s iconic landscape eg Yosemite, as well as the Puget Sound and Hood Canal environments, remember Illahee and Theler .

·         Wind: erosion and deposition (dunes), dust bowl of the 1930s

·         Coastal erosion: wind waves and  tsunamis, currents, alongshore transport, sea level rise as affecting coastal erosion.

·         Erosion produces cliffs, beaches are depositional

·         Human impact on coastal processes, new patterns of erosion and deposition.

·         Speed of these endogenic and exogenic processes varies hence the degree of hazard varies

·         Relationship between wealth and experience of hazards

·         Bremerton and Seattle hazards,

·         Hazard perception.

 

Chapter 9 The Hydrosphere

Hydrologic cycle

  • Phases of water
  • Infiltration, , evaporation, transpiration, evapotranspiration, groundwater, zone of saturation, runoff, subsurface flow
  • Location of Pacific, Atlantic, Arctic and Indian Oceans, also Bering, North, Baltic, Black, Okhotsk, Japan, Yellow, china Seas, Gulf of Mexico, Hudson Bay,
  • Currents circulate water about the ocean basins; two major currents are the Gulf Stream, California Current
  • Cover 71% of Earth and contains 97% of Earth’s water, most of our rain comes from Pacific Ocean
  • 40% of population lives within 100 km of coastlines
  • Source of food, transportation, climate modification, recreation
  • Scientific frontier … still yet to be entirely mapped, still many unknowns
  • Sea is a small ocean
  • Oceans have energy that is dissipated at coastlines
  • Puget sound: narrow arm of sea connecting to the Pacific Ocean
  • Ocean currents: driven by prevailing winds
  • Chemical composition: 35parts/thousand, types of salts  
  • Know: Source of salt, terms brackish brine, areas of the world where salt can be harvested.
  • Sea is a force that erodes and deposits materials within the littoral zone, and especially in the zone between high and low tide
  • Groundwater resources, water aquifer, aquiclude, water table, perched water table, unconfined water table, recharge basins, artesian wells, saltwater intrusion, pollution of ground water, fossil groundwater, watersheds, groundwater resources, aqueducts, saltwater intrusion
  • Depletion of the Ogallala aquifer
  • Bremerton water supply
  • Water as a critical resource with population growth
  • Permafrost: continuous and discontinuous, distribution, permafrost features, patterned ground, pingos, ice wedges, mammoths, ground subsidence with thawing
  • Iceberg location, range of sizes, International Ice patrol, detection and mapping
  • Sea ice, first year ice and multiyear ice, brine drainage, human interactions, detection and mapping, egg code.
  • Glaciers and sea ice thickness and extents are changing; melting is causing a 2-3mm/year sea level rise