Geography 1111 Lecture 21 Notes
Geography 1111 Lecture 21 Notes GEOG 1111
Popular in Intro to Physical Geography
Popular in Geography
This 4 page Class Notes was uploaded by Bridget Notetaker on Friday September 30, 2016. The Class Notes belongs to GEOG 1111 at University of Georgia taught by Hopkins in Fall 2016. Since its upload, it has received 13 views. For similar materials see Intro to Physical Geography in Geography at University of Georgia.
Reviews for Geography 1111 Lecture 21 Notes
Report this Material
What is Karma?
Karma is the currency of StudySoup.
You can buy or earn more Karma at anytime and redeem it for class notes, study guides, flashcards, and more!
Date Created: 09/30/16
Geography 1111 Lecture 21 Notes Introduction to Geomorphology: o Definition: the development and changes on the Earth’s surface over time o Basic Terms: Landform: an individual element of a landscape, a mountain, a valley, etc. Topography: refers to the elevation changes of the Earth’s surface over a given space or distance Ex: ridges, valleys, etc. Uniformitarianism: the idea that the process of change we see today are the same as they were in the past and will be in the future Ex: the way a volcano functions today is the same way that volcanoes “worked” in the past and will into the future Types of Landforms: o Tectonic: those developed by the rearrangement of Earth’s crust, driven by internal energy. Earthquakes, volcanoes, etc. o Fluvial: refers to those developed by flowing liquid water (rivers) o Karst: is a type of landscape developed primarily by the chemical weathering (carbonation) of limestone o Glacial: refers to those landforms developed by glacial ice (solid water) o Eolian: landforms are those developed by wind processes o Coastal: landforms are the result by ocean waves and current processes o Geomorphic Processes are of 2 basic types: 1. External Processes: those that occur on the Earth’s surface, such as fluvial, glacial, wind, coastal, etc. 2. Internal Processes: those that occur or originate within Earth’s crust, volcanism, mountain building, massive crustal rearrangement (plate tectonics), earthquakes, etc. Remember the ideas of equilibrium state, steadystate equilibrium, dynamic equilibrium, negative and positive feedback mechanisms from Lecture 1 Earth’s Internal Structure: o Characteristics: From what we know, the Earth’s interior is composed of or arranged in concentric layers or spheres, with heavier elements having settled toward the center and is the result of cooling since formation of the Earth, some 4.6 billion years before present (BYBP) Each layer is distinct in chemical composition and/or temperature and is either solid, molten, or a combination of the two Our assumptions as to the composition and character of the Earth’s interior are based on analysis of the material in the crust and of molten material (magma/lava) which comes to the surface Analysis of the behavior of seismic waves (the energy waves produced by an earthquake) also helps us understand the interior by analyzing their speed and direction as they pass thru the Earth Seismic waves change in both speed and direction with changes in the temperature and density of material they pass through Cooler material yields higher velocities while hotter material yields slower velocities AND changes in density of the material may reflect or refract the waves Three basic types of seismic waves: 1. P waves or Primary waves, which are push or compression waves 2. S waves or Secondary waves, which are shear or shake waves 3. L waves or Surface waves, which move through the surface/ground and are the waves you feel in an earthquake The Earth’s Layers: o Inner Core: The material in this layer is in a solid state and consists primarily of iron (Fe) and Nickel (Ni) o Outer Core: This layer is in a liquid/molten state, but also consists of Fe and Ni The material in this layer is under less pressure since there is less material on top of it o This causes its melting temperature to be lower, thus the material is in a liquid/molten state The Outer Core also generates most (~90%) of the Earth’s magnetic field Because this layer is molten and the material moves within the layer, it causes fluctuations in the magnetic field over time Discontinuities: exist between layers and are broad, uneven transition zones from areas differing in chemical composition and/or density The discontinuity between the Outer Core and the layer above it (the Lower Mantle) is called the Gutenberg Discontinuity o Lower Mantle: This layer is primarily solid, but with molten material also present and it consists of Fe oxides, magnesium (Mg) and silicon (Si) o Upper Mantle: This layer is a mixture of molten and solid material and consists of silicate minerals The Upper and Lower Mantle comprise about 80% of Earth’s volume and are often together referred to simply as the Mantle o Asthenosphere: It is primarily molten, with some solid material It is the main source (but not the only) of magma, the molten rock or lava which erupts onto the surface o Lithosphere: Consists of two solid layers, the Uppermost mantle, and the Crust There are 2 types of crustal material, Continental and Oceanic which vary in thickness The zone of contact between the Uppermost mantle and the Crust is the Mohorovicic Discontinuity or Moho Continental Crust Oceanic Crust Material of lower density Material of higher density Sialic rock or sial (Si and Aluminum) Simatic rocks or sima (Si and Magnesium) Ex: granite, shale, marble Ex: basalt, lava The Crustal Surface: o Topography or Topographic relief is the vertical difference between the highest elevation and the lowest elevation over a given area, as measured above sea level EX: In Georgia the highest elevation is Brasstown Bald and the lowest elevation is Sea Level (0') o Each continent has a core or nucleus of crystalline rock, called a craton These are usually of low elevation and greater than 570 million years old o Earth’s overall relief as measured above and below sea level is a high at Mt. Everest, and a low of 36,168' below sea level (in the Mariana Trench, Pacific Ocean) This is ~12.34 miles in topographic relief.
Are you sure you want to buy this material for
You're already Subscribed!
Looks like you've already subscribed to StudySoup, you won't need to purchase another subscription to get this material. To access this material simply click 'View Full Document'