Earth Motions, Latitude / Longitude, and the Seasons Flashcards
How can you determine your latitude?
By measuring the height (in degrees) of Polaris above the horizon
How does the location of Polaris change as you change your latitude?
- It is at zenith at 90 degrees north
- For each degree of latitude you move south, Polaris also moves that number of degrees south
- Polaris not visible in Southern Hemisphere
Where is Polaris in the skies above:
1) the North Pole
2) Sudbury
3) the Equator
4) the Tropic of Capricorn
5) the Tropic of Cancer
1) 90 above horizon (zenith)
2) 42.4 above horizon
3) 0 (horizon)
4) 23.5 below horizon
5) 23.5 above horizon
How do you determine the antipode of a location?
- Reverse north and south
- Subtract 180 from longitude
- Reverse east and west
What are latitude lines?
- Imaginary lines that go all the way around the world and are a parallel to the Equator
- Run east to west, measure distances in degrees north and south of equator
Where is the highest possible latitude?
North and South Pole
Where is the Tropic of Cancer located and when is the sun at zenith at this location?
- 25.5 N
* Summer solstice (June 21)
Where is the Tropic of Capricorn located and when is the sun at zenith at this location?
- 23.5 S
* Winter solstice (December 21)
Where is the Arctic Circle located? How much sunlight does it get?
- 66.5 N
- Northernmost latitude on planet
- Receives at least one day (24 hours) of continuous night or day
As you go latitudes north of the Arctic Circle, what happens to the number of consecutive days that receive 24 hours of day?
Increases until you reach the North Pole, which experiences 6 months of continuous day or night
Where is the Antarctic Circle located? How much sunlight does it get?
- 66.5 S
- Southernmost latitude on planet
- Receives at least one day (24 hours) of continuous night or day
As you go latitudes south of the Antarctic Circle, what happens to the number of consecutive days that receive 24 hours of day?
Increases until you reach the South Pole, which experiences 6 months of continuous day or night
How many km of distance along the surface of the Earth is 1 degree latitude?
111 km (slightly larger near the Poles- oblate spheroid)
What are longitude lines? (maximum?)
- Imaginary lines that run across the surface of the Earth from the North to South Pole
- Run north to south, measure distances in degrees east and west of the Prime Meridian
- 180 degrees E and W max
Where is the Prime Meridian?
Greenwich, England- 0 degrees
What/where is the International Date Line?
- Halfway around the world from the Prime Meridian (180 degrees)
- Move East across IDL = subtract calendar day
- Move West across IDL = add calendar day
What does the distance between longitude depend on?
- Where you are on Earth
- Equator - 1 degree longitude = 1 degree latitude (111 km)
- Longitude lines converge at the Poles- distance between them decreases as you move North/South
How is the longitude of a place calculated? (in general)
- By determining the solar time at that place and comparing it with the time at the Prime Meridian
- Earth rotates through 15 degrees of longitude per hour
- Noon = sun at highest point in sky for that day
What is your longitude if it is noon at your location and 3:00 pm at the Prime Meridian?
45 W
3 x 15
What is rotation?
Spinning of the Earth on its axis