physical geography 10th edition "chapter 2: portraying the earth" presentation
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Physical Geography 10th Edition "Chapter 2: Portraying The Earth" PresentationTRANSCRIPT
Chapter 2: Portraying Earth
Ashley AdamsDonald AgabaAlysha BaldwinCory Bragg
The Nature of Maps
MapA two-dimensional representation of Earth
and the spatial distribution of selected phenomena
Basic Abilities of Maps:
•Distance
•Size
•Shape in Their Horizontal Spatial Relationships
Maps are not perfectly Accurate!
It is impossible to portray the curved surface of the Earth on a flat piece of
paper
Map Essentials
MapA form of symbolization, governed by a set of conventions, that aim to communicate a
sense of place (second definition)
6 Groups of Maps:
1) Climate Maps
Give general information about climate and precipitation
2) Economic/Resource Map
Show the types of resources or
economic activities in an
area
3) Physical Maps
Illustrate the
physical features of
an area
4) Political Maps
Show state and national boundaries, & indicate capitals and major cities
5) Road Maps
6) Topographic Maps
Use contour lines to show shape and elevation of an area
Basic Elements of Maps
1. Title2. Date3. Legend4. Scale5. Direction6. Location7. Data Source8. Projection
The Roles of Globes
GlobeA Three-Dimensional Scale model of Earth
or other spheroid celestial body
Globes…
•Accurately represent spatial relationship of features on Earth’s surface
•Give a more realistic depiction of Earth than flat maps
Globe Disadvantages:
•Globes are cumbersome, and do not display much detail
•Globes are only visible to half of the human eye at a time
Map Projections: The Major DilemmaEquivalency vs. Conformity
•Which to EMPHASIZE?
SHAPEor
SIZE
•Which to SACRIFICE?
orSIZE
SHAPE
Equivalent Area Projection
Conformal Map Projection
The Robinson Projection
The 7 Projection Families:
Cylindrical Projection
Mercator Projection
Plane Projection
Conic Projection
Pseudocylindrical Projection
Interrupted Projection
Isolines
A device for portraying the spatial distribution of some phenomenon. It refers to any line that joins points of equal value of something
Also referred to as
•Isarithm•Isogram•Isopleth•Isometric Line
Elevation Contour LinesA line on a map joining points of equal
elevation
Q: What do Isolines signify?
A: Subtle features including…
1)Quantities of Precipitation (Isohyet):
2)Temperature (Isotherm):
3) Atmospheric Pressure (Isobar):
Isolines…
•Are ALWAYS closed lines (they have no end)
•Never touch or cross each other (w/ exceptions)
•Have Intervals (diff. between each line)
Patterns that are too large/abstract/detailed are often significantly clarified by the use of isolines
•Isolines close together – Rapid change
•Isolines far apart – Gradual change
Edmund Halley (1656 – 1742)
•English astronomer & Cartographer
•Produced the first published map with isolines in 1700
▫Showed isogonic lines in the Atlantic Ocean
1st Magnetic Declination Chart (1702)-Edmund Halley
Global Positioning System (GPS)
GPSA global navigation satellite system for
determining accurate positions on or near Earth’s surface
Developed in the 1970’s / 80’s by the U.S. Department of Defense
The system is based on a constellation of at least 24 high altitude satellites
4-6 satellites will be in view of any position on Earth
Wide Area Augmentation System (WAAS)
Was originally put to practice to increase the accuracy of the instrument based
flight approaches for airplanes
Continuously Operating GPS Reference Stations (CORS)
•Capable of detecting location differences of less than 1 centimeter of latitude, longitude, and elevation
•One way they are used is for the monitoring of slight changes in the ground surfaces
Geographic Information System
Geographic Information SystemComputer systems designed to analyze and
display spatial data
Overlay Analysis
The Role of The Geographer
Q: What is The Main Role of a Geographer?
A: To better understand Earth