Mapping Earth & Space sciences 2011 acloutier copyright
MAPPING Earth & Space Science Sandwich High School Annie Cloutier copyright 2011 How do we know where we are ?
Planet Earth is a sphere <ul><li>Early cartographers only knew of a small section of the world, mostly around Europe and the Middle East , the areas they knew & traveled </li></ul><ul><li>Earth may have been named “Earth” due to the limited knowledge at the time ~1,400 YBP </li></ul><ul><li>Today we know that oceans cover over 70% of the Earth </li></ul><ul><li>“ Oceanus” might have been a better name for our planet had they known this fact </li></ul>
Early maps of the world Remember, we thought the world might be flat for a time No one has mapped the new world
The Compass was invented <ul><li>north & south showed L A TITUDE </li></ul><ul><li>to find position, the hemispheres need to be identified first </li></ul><ul><li>northern hemisphere &/or southern hemisphere are established and written first </li></ul><ul><li>The equator is 0* </li></ul><ul><li>The north pole is 90* N </li></ul><ul><li>The south pole is 90* S </li></ul>
<ul><li>east & west are LONGITUDE </li></ul><ul><li>The British named it the “Prime Meridian” </li></ul><ul><li>(the British did have the largest Navy in the world at the time and had lost over a thousand sailors to navigational hazards crashing onto rocks. </li></ul><ul><li>The tragedy sparked the time piece , the CHRONOMITER, to tell how much time had passed since leaving England across the seas. </li></ul><ul><li>John Harrison was the time piece inventor and he won £ 20,000 </li></ul><ul><li>converted to US dollars equals 2.7 million Harrison’s amazing time piece keep time over rough seas . </li></ul>The Royal Society of Scientist decided that Greenwich England was 0* Longitude
One foot is in the East and the other foot is in the West
IDL International Date Line <ul><li>Is not a straight line like the Prime Meridian Line </li></ul><ul><li>Countries wanted to have all their islands in the same time zone for business reasons. </li></ul>
International Date Line 180*West <<<< IDL >>>> 180* East If you were traveling west across the IDL you would move ahead one day If you were moving East across the IDL you would go back a day
Time Zones <ul><li>The Earth is spinning ~ 1,000mph through space </li></ul><ul><li>Time becomes an important variable in direction when traveling </li></ul><ul><li>An Earth day last 24 hours </li></ul><ul><li>24 time zones </li></ul><ul><li>Each longitude line represents 15 * = one hour </li></ul><ul><li>15* x 24 hours = _______ </li></ul><ul><ul><ul><ul><ul><li>spheres are 360* </li></ul></ul></ul></ul></ul>Did you know that what time it is, depends on where you are ?
Poles are 90* <ul><li>North Pole 90* N </li></ul><ul><li>__ _ _ _ _ _ _ _0*_ _ _ _ _ _ __ _equator </li></ul>South Pole 90* S
USA main continent has four time zone Pacific Mountain Central Eastern
Mercator projection points and lines on the globe are transferred to a cylinder-shaped paper Parallel grid on a square paper
Conic projection - made by projecting lines and points from the globe onto a cone. The cone touches the globe at a particular line of LATITUDE. Little distortion of the area or shapes of the land masses. Distortion is obvious at the top and bottom. Conic maps give a high degree of accuracy for a small area. We Cone heads love conic maps. We sometimes wear them for hats
Gnomic Projections are maps that touch the globe at a single point they distort direction & distance *are very useful in plotting long-distance trips by air or sea
Topographic Maps are detailed maps showing changes in elevation of Earth’s surfaces
Contour lines connect points of equal elevations
Hachure lines show a depression or lowering of the elevation
Describe this landscape Can you find the cliff sides of this mountain ?
Wave length & wave characteristics <ul><li>Electromagnetic waves travel at a speed of 300,000km / second </li></ul><ul><li>This is known as the “speed of light” </li></ul><ul><li>Arranged by the lengths of the waves, this forms the distinctive electromagnetic spectrum. </li></ul>
Length of waves of radiation = wavelength Radio waves are100,000 meters long Gamma waves are 0.00000000001 meters long Gamma waves have the highest frequency, radio has the lowest frequency
Remote Sensing is the process of collecting data about Earth from far above Earth’s surface <ul><li>Landsat 7 1999 rocket measured the temperatures of different thermal, energy by features on Earth’s surface </li></ul><ul><li>Landsat satellite receives reflected wave lengths of energy emitted by Earth’s surface including some wavelengths of visible light and infrared radiation </li></ul><ul><li>Topex-Poseidon satellite uses radar to map features on the sea floor sending high frequency signals transmitted from a satellite to the surface of the oceans; a receiver times the returning signal. Using the known speed of light allows us to calculate the distance dividing by 2 into the return time </li></ul>
Sonar and Sea Beam <ul><li>Sea Beam is similar to Topex Poseidon satellite because both are used to map the sea floor. </li></ul><ul><li>Sea Beam is located on the ship rather than on a satellite. The sound is sent from ship, the returning echo is bounced off floor and computers calculate the distance to the bottom using the speed of sound and the time taken to return </li></ul>
GPS > Global Positioning System is a radio-navigation system using at least 24 satellites that allow the user to find exact position on Earth Latitude (North/South & Longitude East/West)