Maps Map projection – “projection” of a spherical earth on a flat surface – “projection” of a spherical earth on a flat surface

Latitude and Longitude Latitude and Longitude are spherical coordinates on the surface of the earth PreTest…

Latitude Angular distance measured in degrees North or South of the equator Angular distance measured in degrees North or South of the equator Lines of latitude that run parallel to the equator.Lines of latitude that run parallel to the equator. Equator divides the globe into the Northern and Southern HemispheresEquator divides the globe into the Northern and Southern Hemispheres

Longitude Angular distance measured in degrees East or West of the prime meridian. Angular distance measured in degrees East or West of the prime meridian.prime meridianprime meridian lines of longitude, called meridians, run perpendicular to lines of latitudelines of longitude, called meridians, run perpendicular to lines of latitude all pass through both poles.all pass through both poles. each longitude line is part of a great circle.each longitude line is part of a great circle.great circlegreat circle Great circle is any circle that goes through the center of the earth. Great circle is any circle that goes through the center of the earth.

Equator—The line which encircles the Earth at an equal distance from the North and South Poles. Equator—The line which encircles the Earth at an equal distance from the North and South Poles. Meridian—any line of longitude; A great circle on the surface of the Earth, passing through the geographical poles and some third point on the Earth's surface. Meridian—any line of longitude; A great circle on the surface of the Earth, passing through the geographical poles and some third point on the Earth's surface. Parallel—A circle or approximation of a circle on the surface of the Earth, parallel to the Equator and connecting points of equal latitude. Parallel—A circle or approximation of a circle on the surface of the Earth, parallel to the Equator and connecting points of equal latitude. Prime Meridian—The meridian of longitude 0 degrees, used as the origin for the measurement of longitude. The meridian of Greenwich, England, is the internationally accepted prime meridian in most cases. Prime Meridian—The meridian of longitude 0 degrees, used as the origin for the measurement of longitude. The meridian of Greenwich, England, is the internationally accepted prime meridian in most cases.

Mercator Projection has correct shapes of continents, but their areas are distorted. Lines of longitude are projected onto the map parallel to each other (square world map) has correct shapes of continents, but their areas are distorted. Lines of longitude are projected onto the map parallel to each other (square world map)

Mercator Projection

Robinson Projection has accurate continent shapes and shows accurate land area has accurate continent shapes and shows accurate land area

Gnomonic Projection used to plot the shortest distance between two points, projected as if a sheet of paper were laid on a point of the Earth’s surface used to plot the shortest distance between two points, projected as if a sheet of paper were laid on a point of the Earth’s surface

Conic (or polyconic) Projection used to produce a map of small areas. They’re made by projecting points and lines from a globe onto a cone. used to produce a map of small areas. They’re made by projecting points and lines from a globe onto a cone.

Conic (polyconic) Projection atlas.usgs.gov/articles/mapping/a_projections.html atlas.usgs.gov/articles/mapping/a_projections.html

Cool website Follow the link below… Follow the link below… peditions/hall/index.html?node=20 peditions/hall/index.html?node=20

Map Scale – the relationship between the distances on the map and actual distances on Earth’s surface

3 types of map scales Verbal: statement “1 inch equals 100 miles”Verbal: statement “1 inch equals 100 miles” Graphic: line divided into equal parts and marked in units (bar scale)Graphic: line divided into equal parts and marked in units (bar scale) Numerical: written as a fraction scale (1/100,000 and 1/24,000) or a ratio scale (1:100,000 or 1:24,000)Numerical: written as a fraction scale (1/100,000 and 1/24,000) or a ratio scale (1:100,000 or 1:24,000)

Which map scale do you see?

Topographic Maps shows the changes in elevation of Earth’s surface

Topographic Maps Contour Line – a line on a map that connects points of equal elevation Contour Line – a line on a map that connects points of equal elevation Contour Interval – consistant difference in elevation between two adjacent (side- by-side) contour lines Contour Interval – consistant difference in elevation between two adjacent (side- by-side) contour lines

Rules to Remember Contour lines: Contour lines: Connect points of equal elevationConnect points of equal elevation Cannot come to a ‘dead end’; they MUSTCannot come to a ‘dead end’; they MUST Go off the map Go off the map Make a closed loop (around hills and basins or depressions) Make a closed loop (around hills and basins or depressions) Cannot crossCannot cross Cannot forkCannot fork Touch ONLY if there is a vertical slope/gradient (like a cliff)Touch ONLY if there is a vertical slope/gradient (like a cliff) Form V’s that point upstream (to the source) whenever they cross streamsForm V’s that point upstream (to the source) whenever they cross streams are far apart in flat areas (gentle slope)are far apart in flat areas (gentle slope) are close together to depict steep slopeare close together to depict steep slope

Features of Topographic Maps Relationship between 3D and 2D representation 3D view 2D view

Contour lines Relationship between topographic features and contour lines

Landforms the smaller features of the earth’s landscape defined by their shape, size and elevation…

Mountain – an elevated area of land, higher than a hill, with sloping sides – an elevated area of land, higher than a hill, with sloping sides

Valley an area of land lower in elevation than its surroundings an area of land lower in elevation than its surroundings

Valley (topographic map) The blue line is the river valley The blue line is the river valley Note the steep sides of the river wallsNote the steep sides of the river walls

Plain an extensive, flat area of land, usually without trees an extensive, flat area of land, usually without trees

Plateau A fairly flat area of land above surrounding land (area of flat land with high ‘relief’) ie. A mesa (below) A fairly flat area of land above surrounding land (area of flat land with high ‘relief’) ie. A mesa (below)

(Relief – the distance from the base to the top (peak, summit) of a landform) (Relief – the distance from the base to the top (peak, summit) of a landform) Relief map… Relief map…

Canyon a valley with very steep sides a valley with very steep sides Canyon DiPetra, Grand Canyon, AZ

Strait a narrow passage of ocean water joining two larger bodies of water a narrow passage of ocean water joining two larger bodies of water ie. Strait of Gibraltar between Africa and Europe ie. Strait of Gibraltar between Africa and Europe

Bay a body of ocean water mostly surrounded by land and smaller than a sea or ocean a body of ocean water mostly surrounded by land and smaller than a sea or ocean

Peninsula a projection of land surrounded on 3 sides by water a projection of land surrounded on 3 sides by water Mani Peninsula Satellite image

Island land completely surrounded by water land completely surrounded by water New Zealand's most active volcano, White Island, was in a state of frequent eruption from 1976 to 2000.

Lagoon a shallow body of salt water mostly or completely surrounded by land a shallow body of salt water mostly or completely surrounded by land

Archipelago a group or chain of islands a group or chain of islands

Archipelago a group or chain of islands

Topographic Profile

Congratulations – you found the hidden extra credit!!! Find: The magnetic declination for our school The magnetic declination for our school A bench mark (picture) A bench mark (picture) Locate the nearest bench mark to school Locate the nearest bench mark to school The latitude and longitude of our school down to the nearest tenth of a second. The latitude and longitude of our school down to the nearest tenth of a second. The latitude and longitude of your house down to the nearest tenth of a second. The latitude and longitude of your house down to the nearest tenth of a second. Present this information to me after school any day before we finish the map unit…. Then sing the hokey-pokey-with me (only one verse) and get a bonus homework assignment.

Azimuthal for example… polar projection… the north pole is ‘touching’ the map and the longitudinal lines radiate outward. for example… polar projection… the north pole is ‘touching’ the map and the longitudinal lines radiate outward.