Mapping the Earth

  • Things you should UNDERSTAND, KNOW, and be able to DO...
    • maps can be used to gain various kinds of information
    • the 3-dimensional world is typically represented on 2-dimensional maps
    • the Earth’s shape is an oblate spheroid
    • lines connecting points of equal values on a map help us represent the 3-dimensional world
    • the space between isolines represents a fixed value
    • topographic maps represent landforms through the use of contour lines that are isolines connecting points of equal elevation.
    • gradients and profiles can be determined from changes in elevation over a given distance. 
    • Earth’s coordinate system of latitude and longitude, with the equator and prime meridian as reference lines, is based upon Earth’s rotation and our observation of the Sun and stars.
    • the altitude of Polaris depends on the latitude of the observer
    • Earth rotates at 15 degrees per hour. Meridians of longitude are the basis for time zones. 
    Terms: axis, troposphere, lithosphere, hydrosphere, known elevation, contour interval, contour line, depression line, elevation, equator, gradient, oblate spheroid, isoline, field value, latitude, longitude, Polaris, pole, Prime Meridian, profile, time zone, topographic
    • use Earth Science Reference Tables (ESRT) to gain information
    • describe the composition of the Earth’s crust, hydrosphere and troposphere using the ESRT 
    • determine direction using a compass rose
    • use data to draw isolines
    • use a scale on a map to determine distance
    • construct and interpret a topographic profile
    • determine values of and between isolines
    • calculate gradient using a topographic map and/or field values
    • determine the direction of stream flow from a topographic map
    • estimate maximum and minimum values on an isomap
    • interpret and label depression contours (hatchure lines)
    • determine the latitude and longitude of a given point to the nearest degree
    • calculate local time based on longitude
    • determine latitude by use of the star Polaris
    • determine the angle from horizon to Polaris using an astrolabe and relates this to latitude