Module 5 Study Guide PDF

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This is a completed study guide for Dr. Henry's GEO 122 class, Module 5. It included definitions, examples, and links to information....

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GEO 121/122 Module 5 Study Guide (Dr. Henry)  Introducing Physical Geography (6th Edition) by Alan Strahler (2013) Wiley, 664 pp. ISBN: 978-1-118-39620-9 or Fundamentals of Physical Geography http://bit.ly/funphysgeog ! Topics marked with ! are not in the ebook, but should be easily found online elsewhere (just basic background info- I have some suggested links). (g) Topics marked with (g) are in the ebook glossary.  Ebook: Chapter 10: Introduction to the Lithosphere  Module 5 is on plate tectonics and weathering, but you will be focusing most on hazards- there are some sections that you can pretty much skip, as they will not be important for the next team activity.  Chapter 11: Earth Materials & Plate Tectonics http://www.physicalgeography.net/fundamentals/10a.html The Rock Cycle http://www.physicalgeography.net/fundamentals/10b.html Geologic Time http://www.physicalgeography.net/fundamentals/10e.html Characteristics of Igneous Rocks http://www.physicalgeography.net/fundamentals/10f.html Characteristics of Sedimentary Rocks http://www.physicalgeography.net/fundamentals/10g.html Characteristics of Metamorphic Rocks http://www.physicalgeography.net/fundamentals/10h.html Structure of the Earth http://www.physicalgeography.net/fundamentals/10i.html Plate Tectonics http://www.physicalgeography.net/fundamentals/10o.html Physicography of Earth’s Terrestrial Surface  structure of Earth's interior (order of layers, role of layers in plate tectonics) (10h) ● crust (ocean vs. continental): topmost part of the lithosphere, made of cool, brittle, rigid material; both oceanic and continental crust are less dense than the rocks making up the upper mantle layer below them; both crusts are composed of tectonic plates that float on top of the mantle and can be moved by convection currents within the mantle ○ Oceanic crust: thin, between 5 and 10 kil thick, composed of basalt with a density of 3 grams per cubic centimeter ○ Continental crust: 20-70 kil thick, composed of a lighter granite, density is 2.7 grams per cubic centimeter; thickest beneath mountain ranges and extends into the mantle ● Asthenosphere: t he top layer of the upper mantle, 100-200 kil below the surface, rocks in this layer are more brittle and rigid because of cooler temperatures and lower pressure

Lithosphere: layer that includes the crust and the upper-most part of the mantle, has ability to glide over the rest of the upper mantle; deeper portions are capable of plastic flow over geologic time; zone of earthquakes, mountain building, volcanos, and continental drift ● Mantle: the thickest layer of the Earth, 2900 kil thick, comprised of the upper mantle, which starts from the crust and goes for 670 kil, and the lower mantle, which goes from 670 kil to 2900 kil below the surface and is hot and plastic with higher pressure ● outer core: at earth’s center, located around the inner core, liquid ● inner core: a  t earth’s center, theorized to be solid rock types (How do they form? Where are they located?) (10e, 10f, 10g) ● Igneous: produced by the crystallization and solidification of molten magma ● Sedimentary: 3  groups ○ Formed by lithification of weathered rock debris that have been transported and deposited (e.g. sandstone) -> called clastic ○ Created from chemical precipitation and crystallization -> called non-clastic ○ Lithification of once living organic matter -> called non-clastic ● Metamorphic: c an occur in three ways ○ Thermal metamorphism: involves the heating and structural and chemical alteration of rocks through processes associated with plate tectonics; 2 sub categories ■ Regional: large scale ■ Contact: small scale ○ Dynamic metamorphism: causes only the structural alteration of rock through pressure. The minerals in the altered rocks do not change chemically. The extreme pressures associated with mountain building can cause this type of metamorphism ○ Metasomatic metamorphism: involves the chemical replacement of elements in rock minerals when gases and liquids permeate into bedrock. ● don't worry about minerals or chemical content of rocks rock transformation/cycle (Figure 11.17, 10a) ● a general model that describes how various geological processes create, modify, and influence rocks (Figure 10a-1). This model suggests that the origin of all rocks can be ultimately traced back to the solidification of molten magma. Magma consists of a partially melted mixture of elements and compounds commonly found in rocks. Magma exists just beneath the solid crust of the Earth in an interior zone known as the mantle ●

  geologic time (not the specific time divisions, but understanding how it differs from human time scales) (10b) ● Eons, eras, periods, and epochs (largest to smallest) ● Established at the occurrence of some important geologic event  See see p. 402-403 map (and slides) and know examples of these formations: (10o) ● alpine chains (e.g., Alps, Himalayas) ● continental shields (see slides): large stable area of Earth’s crust under low relief ● continental rupture (rift valley → narrow ocean → large ocean): o  ccurs when tectonic forces uplift a plate of the lithosphere and pull it apart (ex: the Red Sea) ● island arc (e.g., Japan, New Zealand): a curved chain of volcanic islands located at a tectonic plate margin, typically with a deep ocean trench on the convex side  plate tectonics (10i) ● extensional tectonic activity: activity that forms structures by stretching the lithosphere or crust ● compressional tectonic activity: activity that forms structures by shortening and thickening the crust plates and boundaries (examples of each, where they are located, landforms associated with each)

spreading boundary: linear feature that exists between plates that are moving away from each other ● convergent boundary: 2 or more lithospheric plates are colliding; one plate eventually slides beneath the other, leading to subduction ● subduction zones: r egion of Earth’s crust where tectonic plates meet continents of the past ● Pangea   Chapter 12: Volcanic & Tectonic Landforms http://www.physicalgeography.net/fundamentals/10l.html Folding & Faulting http://www.physicalgeography.net/fundamentals/10m.html Earthquakes http://www.physicalgeography.net/fundamentals/10n.html Volcanoes  Japan earthquake & tsunami of 2011 ! (or this source) What tectonic setting and event caused this earthquake and tsunami? !  ● The Pacific Plate subducts beneath the Eurasian plate; the two plates were rocky, and stuck together. When they finally shifted, an immense amount of pressure was released, causing the plate to shift 50 meters and instigating the earthquake and tsunami tectonic landforms (especially faults) ● Japan Trench What geologic setting results in the different types? (10l) ● normal fault: 2  plates moving away from each other, resulting with a downthrown and upthrown block ● Graben: a  block has been lowered relative to the blocks around it ● Horst: a block has been raised higher relative to the blocks around it ● strike-slip fault: two plates move horizontally against each other in opposing directions (hands sliding together) ● reverse fault: two plates push against each other with one going down and the other going up, resulting in landsliding ● overthrust fault: w  here older rocks are thrust above younger rocks  Earthquakes (10m) How do plate tectonics cause earthquakes? ● Friction can prevent plates from moving, causing a buildup of potential energy. When it is released as kinetic energy, an earthquake can happen. Where do earthquakes tend to occur (geologically)? ● Tend to occur along faults, tectonic plate boundaries, or mid-oceanic ridges Tsunamis (10m) What causes a tsunami and where do they tend to occur? ● Sudden movement of the seafloor causes waves that radiate outward in concentric shells. In open ocean, waves are only 1-3 meters high. However, as they get closer to ●

land, the waves slow and collide with each other. This produces a super wave that can be as tall as 65 meters.  volcanic landforms (especially active volcanoes) (10n) Where are they found, how do they compare in terms of size and eruption type? ● Found at subduction zones and mid-oceanic ridges ● stratovolcano (composite): alternate layers of exploded rock and lava layers, 100-3500 meters tall; magma has more granite, and is therefore more explosive due to a higher water content ● shield volcano: produce very fluid basaltic magma, flat to gently sloping (e.g Hawaiian islands) ● hotspot volcano: an area in the mantle from which heat rises as a thermal plume from deep in the Earth. High heat and lower pressure at the base of the lithosphere (tectonic plate) facilitates melting of the rock. This melt, called magma, rises through cracks and erupts to form volcanoes ● cinder cone: small, 100-400 meters tall, made up of exploded rock, form when large amounts of gas accumulate in rising magma  Well known tectonic landforms (see slides) ● East African Rift Valley ● Mariana Trench ● Mauna Loa, Hawaii ● Mid-Atlantic Ridge ● Mt. Rainier, Washington ● San Andreas Fault  Chapter 13: Weathering & Mass Wasting http://www.physicalgeography.net/fundamentals/10r.html Weathering http://www.physicalgeography.net/fundamentals/10x.html Mass Movement  weathering processes (just overview for context in mass wasting) (10r) What are the major types of weathering and where do they occur? ● Freeze-thaw: as it freezes, water volume grows by about 9%, causing cracks ● salt-crystal growth (crystallization): crystals form with change in temperature, salt changes volume from 1-5% ● exfoliation (unloading): u  nloading of pressure causes horizontal pressure mass wasting (types, causes, where they occur see slides) (10x) ● soil creep: Slow mass movement of s oil downslope. Occurs where the stresses on the slope material are too small to create a rapid failure ● earthflow, mudflow: F  orm of mass movement where fine textured s ediments and s oil mix with water to create a liquid flow ● Landslides: Term used to describe the downslope movement of soil, r ock, and other weathered materials because of gravity. 

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Rockfall: T  ype of mass  movement that involves the detachment and movement of a small block of rock from a cliff face to its base. Normally occurs when the rock has well defined bedding planes that are exaggerated by freeze-thaw action or thermal expansion and contraction. lahar (g  ): A very rapid type of downslope mass movement that involving m  udflows from volcanic ash. 

 Sample Quiz Questions for this Module: ● The presence of sedimentary rock in an area can tell you that ________. ● Weathering processes that rely on freeze-thaw action are most common in which climates? T  he poles?? Places where it drops below freezing at night ● Most violent volcanic eruptions are caused by ________. Change in pressure, temperature, or tectonic activity ● What does a slump look like? ...