Geog1- Midterm Section 1

Front 1

Antartic Circle

Back 1

66.5 S parallel

Front 2

aphelion

Back 2

The point in Earth's elliptical orbit at which the Earth is farthest from the Sun.

Front 3

Arctic Circle

Back 3

66.5 N parallel

Front 4

circle of illumination

Back 4

The edge of the sunlit hemisphere that is a great circle separating Earth into a light and dark half.

Determines the length of day.

During the Equinox it splits in half along the poles.

Front 5

equator

Back 5

The parallel of 0 latitude.

Geographical reference point.

Things move the fastest here due to rotation.

Reference point for latitude.

Front 6

equatorial plane

Back 6

An imaginary plane that passes thru Earth halway between the poles and perpendicular to the axis of rotation.

Front 7

equinox

Back 7

Point where the subsolar point is at the equator. Twice a year- March 20th & September 22nd. "The time of equal days and nights."

Circle of illumination touches both poles making daylight and darkness each 12 hours all over Earth.

Represent the midpoints in the shifting of the rays of the Sun between the two tropics.

Front 8

inclination of the sun

Back 8

Latitude of the subsolar point, or where the sun is 90 degrees overhead.

Front 9

international date line

Back 9

Separates one day from another.

180 meridian, Greenwich.

Cross it going west: Earlier in clock time, a day later.

Front 10

latitude

Back 10

Part of the geographic reference grid.

0 reference is the equator. Goes to 90 at the poles.

Says how far away North or South you are from the equator.

Important parallels: Equator, North Pole, South Pole, Tropic of Cancer, Tropic of Capricorn, Arctic Circle, and Antarctic Circle.

Front 11

longitude

Back 11

Part of the geographic reference grid.

Runs North and South, imaginary lines extending from pole to pole.

Also called meridians.

Only parallel where they cross the equator.

Prime meridion runs thru Greenwich, England. Measured east to west up to 180 degrees from the PM.

Front 12

meridian

Back 12

Another name for the longitude.

An imaginary line of longitude extending from pole to pole, crossing all parallels at right angles.

Front 13

parallel

Back 13

Another name for the latitude.

A circle resulting from connecting all the points on a line of latitude.

Front 14

perihelion

Back 14

The point in its orbit where Earth is closest to the sun.

Front 15

plane of the ecliptic

Back 15

The orbital plane of the Earth around the sun.

Front 16

polarity (parallelism)

Back 16

A characteristic of Earth's axis where it always points towards Polaris (North Pole) at every point in its orbit around the sun. Axis is always parallel to itself at other points in its orbit.

Front 17

prime meridian

Back 17

The meridian passing throught the Royal Observatory in Greenwich England from which longitude is measured.

Front 18

solstice

Back 18

Point where the subsolar point is at one of the Tropics (23.5).

Twice a year. June 21st (24 hours of daylight at North pole, Tropic of Cancer) & December 21st (24 hr daylight at South Pole, Tropic of Capricorn)

Tilt of the Earth is at its most extreme towards or away from the sun.

Front 19

subsolar point

Back 19

Point at where the sun is 90 degrees overhead.

Remains at the same latitude throughout the day

The declination of the sun is the latitude of the subsolar point which changes over the course of the year.

This is the place that recieves the most solarenergy.

Front 20

Tropic of Cancer

Back 20

Parallel of 23.5 degrees North.

Marks the northernmost location reached byt he vertical rays of the Sun during Earth's revolution.

Front 21

Tropic of Capricorn

Back 21

Parallel of 23.5 degrees South.

Marks the southernmost location reached by the vertical rays of the Sun during Earth's revolution.