Ch.2: Mapping Our World Text ref. (pg.26)

Contents Latitude and Longitude Types of Maps Remote Sensing

Latitude and Longitude Text ref. Ch.2.1, p.27-31

Objectives Compare and contrast latitude and longitude. Describe how time zones vary.

Cartography Science of mapmaking. Use a series of imaginary grid of parallel lines and vertical lines Equator circles Earth halfway between north and south poles

Latitude Latitude is the distance in degrees north or south of the equator. Equator is equal to 0° latitude Poles are equal to 90° latitude North latitude from equator to the North Pole. South latitude from equator to South Pole.

Degrees of Latitude 1 degree of latitude is equal to about 111 km. Cearth= 40 000 km therefore, 40 000 km/360 = 111 km. Smaller units of measure for latitude include minutes ‘ and seconds “ . Ex. Mobile is located at 30.694N latitude.

Longitude Longitude is the distance in degrees east or west of the prime meridian. The prime meridian represents 0° longitude. Located through Greenwich, England 0° to 180° E and W of prime meridian

Semicircles Lines of longitude not parallel Extend vertically from pole to pole Line of longitude directly opposite the prime meridian equal to 180° Known as International Date Line

Degrees of Longitude Distance covered by degrees of longitude varies in relation to distance from equator. Greatest at equator (111 km), approaches a point at the poles

Location with Coordinates Latitude and longitude both needed for accurate global conditioning Mobile: 30° 40' N 88° 15' W San Francisco Co: 37° 46' N 122° 26' W NYC-Central Park (S): 40° 47' N 73° 58' W Tokyo: 35° 41' N 139° 46' E Baghdad: 33° 20' N 44° 24' E

Time Zones Earth divided in 24 time zones for each of the 24 hours of a day Time zones 15° wide U.S. spans 6 time zones

Calendar Dates By traveling through time zones you gain or lose time until you gain or lose an entire day. International Date Line located at 180° is the calendar line for days Travel west across the International Date Line and you advance one calendar day, east across and you lose one calendar day.

Types of Maps Text ref. Ch.2.2: p.33-36

Objectives Compare and contrast different map projections Analyze topographic maps Describe map characteristics, such as map scales and map legends.

Mercator Projections Map that has parallel lines of latitude and longitude Landmasses near poles are distorted, exaggerated Ex. Greenland appears larger than Australia Use: navigation of planes and ships

Conic Projections Made by projecting points from a globe onto a cone. Very little distortion in landmasses and their sizes Useful for smaller maps of regional areas, cities, and roadmaps.

Gnomonic Projections Made by projecting points and lines from a globe onto a piece of paper that touches the globe at a single point. Distort direction and distance between landmasses Useful in planning shortest distance between two points by displaying Great Circles of longitude and latitude.

Topographic Maps Show changes in the elevation of the Earth’s surface, as well as features such as mountains, rivers, forests, and bridges. Use lines, symbols, and colors to represent changes in elevation.

Contour Lines on Topographic maps Elevation on topographic maps represented by contour lines Connects points of equal elevation Contour lines never cross

Contour Intervals on Topographic maps Used to show changes in elevation from one contour line to another Mountains have greater contour intervals between contour lines than do plains or hills

Index Contours in Topographic Maps Used to aid in interpreting the elevation of landmarks and terrain on a topographic map. Marked by numbers representing elevation For example, if contour interval is 10 m, you can subtract or add 10 m for each interval from the index contour to determine the elevation at that location.

Depression Contour lines in Topographic maps To represent areas of lower elevation than their surroundings, depression contour lines will have hachures Short lines at right angles to the contour line Point toward the area with the lower depression.

Map Legends Natural and human-made features are represented by symbols on maps

Map Scales Defines the ratio between distances on a map and actual distances on the surface of Earth Verbal: expresses ratio as a statement Graphic: consists of a line that represents a certain distance. Fractional: expresses distance as a ratio

Ch.2.3: Remote Sensing Text ref. p 37-41

Objectives Compare and contrast the different forms of radiation in the electromagnetic spectrum. Discuss how satellites and sonar are used to map Earth’s surface and its oceans. Describe the Global Positioning System

The Electromagnetic Spectrum Arrangement of electromagnetic radiation according to wavelengths Electromagnetic radiation (i.e. light) Speed = 300 000 km/s or 186 000 mi/s Types of EM radiation are defined by their frequency and wavelength Frequency is the number of wavelengths that occur each second

Landsat Satellites Receives reflected wavelengths of energy emitted by Earth’s surface Infrared imaging allows for detailed images of lakes, rivers, forests, etc… Mirrors based on satellite with light-sensitive detectors Computer image conversion Landsat 7 1999, maps 185 km2 Can map the Earth in 16 days

Topex/Poseidon Satellite Uses radar to map features of ocean floor “Topex”= topography experiment Beacons on ocean surface reflect high frequency radar send by Topex Distance to water’s surface calculated by wave speed formula v = λ x f

The Global Positioning System GPS Radio-navigation system of 24 satellites used to determine exact position on Earth Originally devised by the military for strategic operations Hand-held GPS unit can calculate the latitude and longitude of a location by processing signals of multiple GPS satellites.

GPS continued… Uses: Navigation of ships and planes Earthquake detection Map generation Wildlife/ecology research

Sea Beam Technology used to map the ocean floor Located on ship rather than satellite-based SONAR technology used for mapping Sound waves sent from ship bounce off ocean floor and return to receiver on ship. Distance calculated using wave speed formula

Uses of Sea Beam Fishing fleets Deep-sea drilling operations Oceanographers Volcanologists Archeologists