600 likes | 763 Views
Geographic Communication Today Harvard Extension School ISMT-E155 Jeff Blossom, Instructor jblossom@cga.harvard.edu. Week 1 January 27 2014 . 5:30 - 5:45 Why Geographic Communication? Why me ? 5:45 - 6:00 Why you?
E N D
Geographic Communication Today Harvard Extension School ISMT-E155 Jeff Blossom, Instructor jblossom@cga.harvard.edu Week 1 January 27 2014 5:30 - 5:45 Why Geographic Communication? Why me? 5:45 - 6:00 Why you? - Introduce name, what you do, why you're taking the class, and any special mapping interests you may have. 6:00 - 6:40 Review the syllabus 6:40 – 6:50 5 minute paper and break 6:50 – 7:20 Lecture: The origins of mapping. Modeling the Earth.
Geographic: geo – “the earth” graphos – “to write” Geography – To describe or write about the Earth. Communication – a process whereby meaning is shared between two living organisms. Why “Geographic Communication”?
Where is the Wal-Mart in Bellingham, MA? • ½ mile South of Maple St. on Hartford Ave. • 250 Hartford Ave Bellingham, MA 02019 • Highway 126 & Hartford Ave. • 42.116912,-71.464605 • “Just past the power lines before you get to 495” • “Where the old service station used to be on Route 126”
Where is the Wal-Mart in Bellingham, MA? Maps are the means by which geographic information is communicated visually.
-34.86,-56.17 Montevideo, Uruguay
Map of India (general reference map) Population density map (thematic map) darker color = higher population density
Nevada Kansas
Geographic Communication Today Harvard Extension School ISMT-E155 Jeff Blossom, Instructor jblossom@cga.harvard.edu Week 1 January 27 2014 5:30 - 5:45 Why Geographic Communication? Why me? 5:45 - 6:00 Why you? - Introduce name, what you do, why you're taking the class, and any special mapping interests you may have. 6:00 - 6:40 Review the syllabus 6:40 – 6:50 5 minute paper and break 6:50 – 7:20 Lecture: The origins of mapping. Modeling the Earth.
IntroductionsTeaching assistant: Stacy Bogansbogan@cga.harvard.edu Why you?- Introduce name- what you do- why you're taking the class- special mapping interests you may have
Geographic Communication Today Harvard Extension School ISMT-E155 Jeff Blossom, Instructor jblossom@cga.harvard.edu Week 1 January 27 2014 5:30 - 5:45 Why Geographic Communication? Why me? 5:45 - 6:00 Why you? - Introduce name, what you do, why you're taking the class, and any special mapping interests you may have. 6:00 - 6:40 Review the syllabus (handout) 6:40 – 6:50 5 minute paper and break 6:50 – 7:20 Lecture: The origins of mapping. Modeling the Earth.
Lab assignment requirements • Answer questions in a Word or text file. • Export maps in PDF or PNG format. • Map data into KML format. • Upload the Word, PDF, and KML files to the course website drop box • If having problems with the Dropbox, submitting labs via email is fine. • Labe are due 9 days after assignment (the following Friday at midnight) • Need clarification or having trouble? Email anytime, come to office hours before and after class.
An 8 GB USB flash drive • Access to a PC with internet connection • and installation privileges • At least 5 hours a week commitment • Lecture slides will be available on the class website, prior to class. What you will need for this class
Geographic Communication Today Harvard Extension School ISMT-E155 Jeff Blossom, Instructor jblossom@cga.harvard.edu Week 1 January 27 2014 5:30 - 5:45 Why Geographic Communication? Why me? 5:45 - 6:00 Why you? - Introduce name, what you do, why you're taking the class, and any special mapping interests you may have. 6:00 - 6:40 Review the syllabus (handout) 6:40 – 6:50 5 minute paper and break 6:50 – 7:20 Lecture: The origins of mapping. Modeling the Earth.
Week 1 five minute paper <handout>
Geographic Communication Today Harvard Extension School ISMT-E155 Jeff Blossom, Instructor jblossom@cga.harvard.edu Week 1 January 27 2014 5:30 - 5:45 Why Geographic Communication? Why me? 5:45 - 6:00 Why you? - Introduce name, what you do, why you're taking the class, and any special mapping interests you may have. 6:00 - 6:40 Review the syllabus (handout) 6:40 – 6:50 5 minute paper and break 6:50 – 7:20 Lecture: The origins of mapping. Modeling the Earth.
The origins of mapping and modeling the Earth A map is a visual representation of an area. Nearly all maps depict something on Earth, and are thus geographic in nature.
Map of the human brain 3d map of space matter
The first map 16,500 BC - Star maps on cave walls (France) ~12,000 BC -Map engraved on a mammoth tusk (Ukraine)
The first maps - Babalonians Babylonian world map preserved on a clay tablet. ~2300 BC
Mapping advancements – Ancient Greece Aristotle (384-322 B.C.E.) Proved the Earth is round, evidenced by: • The lunar eclipse is always circular • Ships seem to sink as they move away from view and pass the horizon • Some stars can be seen only from certain parts of the Earth. These observations led to modeling the Earth as a sphere
Mapping advancements – Ancient Greece Sphere – a perfectly round object in 3 dimensional space, with all points on the surface lying the same distance from the center. HeraclidesPonticus (390-310 B.C.) – Proposed the Earth rotates on its axis, east to west, once every 24 hours.
Spherical geometry: Great circles, hemisphere Great circle - the circular intersection of a sphere and a plane which passes through the center point of the sphere. • All lines of longitude and the Equator are great circles • Two hemisphere’s (half of a sphere) are created on either side of the plane
Spherical geometry: Small circles Small circle - the intersection of the sphere and a plane which does not pass through the center point of the sphere. All lines of latitude except for the Equator are small circles. Lines of latitude (small circles) great circle (Equator)
Mapping advancements – Ancient Greece Eratosthenes (275–195 B.C.E.) • First used the word “Geography” • Approximated the circumference of the Earth. • Wrote “On the Measurement of the Earth” • Put forth that accurate mapping depends on accurate linear measurement. • Proposed using meridians and parallels to base accurate measurements on.
19th century reconstruction of Eratosthenes' map of the known world, 194 BC.
Meridian – an imaginary line running north to south. Parallel - an imaginary line running east to west. Allowed for the description of places on Earth in as referenced to parallels and meridians
Meridian – an imaginary line running from the north pole to the south pole connecting all points along the same longitude. Parallel - an imaginary line circling the globe running due east to west, connecting all points along the same latitude angle.
Coordinate systems • Coordinate system – a system which uses one or more numbers to uniquely determine the position of a point. • Two axes (X and Y) on a horizontal plane • Equally spaced linear units
0,0 (origin) X axis Y axis
Geographic coordinate system • A geographic coordinate system is a coordinate system that enables every location on the Earth to be specified by a pair of numbers. • Commonly uses values of longitude and latitude to represent horizontal positions on Earth. For example -71.10, 42.37 (longitude, latitude) represents a point in Cambridge, MA.
Mapping advancements – Ancient Greece Euclid (323-283 B.C.E.) – the father of Geometry • Geometry – “Earth measuring” • A branch of mathematics concerned with shape, size, and relative positions of figures. • Two fundamental types of measurements: distances and angles A B For example: the distance from A to B equals 1 stadia Distance – a numerical description of how far apart objects are, using a common reference unit.
Euclidian Geometry - Angle Angle – a figure formed by two rays sharing a common end point: Ray – a line that is finite in one direction, but infinite in the other. ray 2 ray 1 endpoint
Euclidian Geometry - angle The magnitude of an angle is the amount of rotation that separates the two rays: axis of rotation more magnitude less magnitude
Euclidian Geometry - degree A degree, denoted by a small superscript circle (°), is 1/360 of a full circle. One full circle is 360° 360° 0° 270° 90° 90° angle 180°
Longitude: An angular distance east or west of a point on the Earth’s surface, measured from the center of the Earth.
Measuring longitude • Prime Meridian—The meridian of longitude 0 degrees, used as the origin for the measurement of longitude. • Longitude at a point may be determined by calculating the time difference between that at its location and the time at the prime meridian. • Since there are 24 hours in a day and 360 degrees in a circle, the sun moves across the sky at a rate of 15 degrees per hour (360°/24 hours = 15° per hour). • So if local time (where a person is) is four hours ahead of time at the prime meridian, then that person is at 60° longitude (4 hours × 15° per hour = 60°).
Latitude: An angular distance north or south of the Equator measured from the center of the Earth.
Latitudinal references Polaris • The north pole and south pole mark the opposite positions on the axis around which the earth rotates. • The Equator is a great circle located halfway between the poles, and is used as the origin reference for latitude. • Polaris (the north star) is a located directly above the north pole, and is visible as a fixed position in the sky about which the Earth rotates. Equator axis
Measuring latitude Polaris 45° Horizon • Measure the angle from the horizon to Polaris (or Sigma Octantis in the Southern Hemisphere) • using an astrolabe, cross staff, sextant, or other tool. This is your latitude.