Geography Chapter 2 - Notes PDF

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Geography Chapter 2- Portraying Earth 1. Maps and Globes a. Maps- a flat representation of Earth, shown reduced in size with only selected features of data showing. i. “Portray distance, direction, size, and shape in their horizontal spatial relationships.” ii. Thematic maps- have a special purpose and set of information to convey iii. Map Distortions 1. Most maps are not entirely accurate… it is virtually impossible to represent Earth completely due to its curved nature. 2. Map Scale- “describes the relationship between the distance measured on a map and the actual distance it represents on the Earth’s surface.” a. Scale Types i. Graphic Map Scales- “uses a line marked off in distances to represent actual distances on Earth’s surface.” 1. Simple to understand 2. Very common ii. Fractional Map Scales- “conveys the relationship between distance measured on a map and the actual distance that represents on Earth with a fraction or ratio called a representative fraction . ” iii. Verbal Map Scales- “also known as a word scale  states in words the relationship between the distance on the map and the actual distance on Earth’s surface, such as “one centimeter to ten kilometers” and “one inch equals five miles.”” 1. Very similar to fractional map scales b. Large Scale and Small Scale Maps i. Large Scale Map- contains a large ratio for representing distance 1. Ex: 1/ 10,000… shows a small part of a single city ii. Small Scale Map- contains a small ratio for representing distance 1. Ex: 1/10,000,000… shows about ⅓ of the United States 3. Map Projections and Properties a. Map Projections- “a system in which the spherical surface of Earth is trandformed for display on a flat surface.” i. No matter what, images on maps will be distorted from actual size and scale. b. Map Properties i. Equivalence- “the correct size ratio of area on the map to the corresponding actual area on Earth’s surface is maintained over the entire map.” 1. Easily done in larger maps in comparison to smaller maps. ii. Conformality- “proper angular relationships are maintained across the entire map.”

1. Often times things must be considerably distorted in order to give off the proper shape. iii. Compromise Projection- “”neither equivalent nor conformal but instead balances reasonably accurate shapes with reasonably accurate areas.” 4. Families of Map Projections a. Cylindrical Projections- “obtained by “wrapping” the globe with a cylinder of paper in such a way that the paper touches the globe only at the globes equator which is called the circle of tangency  and become the standard parallel  of projection.” i. Mercator--- the Most Famous Projection: 1. “Devised in 1569 by Gerhardus Mercator… the Mercator projection is a conformal map projection designede to facilitate oceanic navigation.” a. Loxodrome- “a line on the surface of a sphere that crosses all meridians at the same angle and represents a line of constant compass directions.” b. Planar Projections- “obtained by projecting the markling of a center-lit globe onto a flat piece of paper that is tangent to the globe at one point.” i. Typically only show one hemisphere ii. “Useful for focusing attention on a specific region.” c. Conic Projections- “obtained by projecting the markings of a center-lit globe konto a cone wrapped tangent to, or intersecting, a portion of the globe.” i. Distortion increases as you gain distance from the standard parallel. d. Pseudocylindrical Projections- “roughly a football-shaped map”... used for lesser regions i. Interrupted Projections 1. In order to lessen distortions on pseudocylindrical projections, ocean masses are “interrupted.” 5. COnveying Information on Maps a. Map Essentials i. Title ii. Date iii. Legend iv. Scale v. Direction vi. Location vii. Data Source viii. Projection Type b. Isolines- “any line that joins points of equal value of something.” i. Elevation contour lines- “connect points of equal elevation on topographic maps.” ii. Isotherm- a line joining points of equal temperature iii. Isobar- a line joining points of equal atmosphewre pressure iv. Isohyet- a line joining points of equal quantities of precipitation

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Isogonic line- a line joining points of equal magnetic declination. Characteristics of Isolines 1. They are closed lines 2. Isolines cannot touch or cross one another. 3. Numerical difference between one isoline and the next is called the interval. 4. Isolines close together indicate a steep gradient. vii. Drawing Isolines 1. ??? c. Portraying the Three-Dimensional Landscape i. Elevation Contours 1. Represent elevation of landforms on maps. ii. Digital Elevation Models 1. An electronic representation of elevation and laandforms usually limited to paper maps. 6. GNSS- Global Navigation Satellite SYstem a. GNSS- a system of navigational programs… led to the creation of GPS. b. Wide Area Augmentation System i. “Icrease the accuracy of instrument-based flight approaches for airplanes.” c. Continuously Operating GPS Reference Stations (CORS) i. “Can detect location differences of less than one centimeter of latitude, longitude, and elevation.” ii. Used to monitor changes in physical features on the Earth. d. GPS Modernization Program i. Replace satellites ii. Greater accuracy e. GPS Application i. Used for navigation for travelling ii. Used for weather iii. Used for cellphones and other electronics f. GPS Display of Latitude and Longitude i. Usually an optional thing 7. Remote Sensing- “refers to any measurement or aquisition of information by a recording device that is not in physical contact with the object under the study-- in this case, Earth’s surface.” i. Aerial Photographs 1. Used for mapping and reliable measurments ii. Orthophoto Maps 1. “Multicolored, distortion-free photographic map prepared from aerial photographs or digital images.” b. Visible Light and Infrared Sensing

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Electromagnetic Radiation- includes a wide range of wavelengths of energy emitted by the sun and other objects. ii. VIsible Light- the colors seen in the rainbow iii. Color Infrared- uses electronic sensors or photographic film sensitive c. Thermal Infrared Sensing- middle or far infrared part of the electromagnetic spectrum i. Need special sensors in order to be detected ii. “Measures the radiant temperature of objects and may be carried out day or night.” iii. Show temperature differences between land and water, bedrock and sediment. iv. Used in meteorological satellites to detect weather\ d. Multispectral Remote Sensing i. Most remote sensing satellites are multispectral and “detect and record many bands, or regions, of the electromagnetic spectrum simultaneously.” ii. Landsat 1. NASA imaging program which gave clear pictures of the Earth from space. iii. Earth Observing System Satellites 1. Featured the Moderate Resolution Imaging Spectroradiometer (MODIS) which “gather data in 36 spectral bands and provides images covering the entire planet every one to two days.” iv. Commercial High-Resolution Satellites 1. HIgh resolution satellites used for private companies such as Google v. Radar, Sonar, and Lidar 1. Passive Systems- “sense the natural radiation emitted by or reflected from an object” 2. Active system- “”has its own source of electromagnetic radiation.” a. Radar- (radio detection and ranging) used in terrain analysis and weather detection...doppler radar b. Sonar- (sound navigation and ranging) used for underwater imaging. c. Lidar (lights and radar)- used for measuring distances. 8. Geographic Information Systems a. GIS- Computer systems designed to analyze and display spatial data. b....