MEASURING EARTH
I EARTH’S SHAPE AND SIZE
1) VERY CLOSE TO BEING A PERFECT SPHERE
2) OBLATE SPHEROID
A) FLATTENING AT THE POLAR REGIONS
B) SLIGHT BULGE AT THE EQUATOR
3) EVIDENCE
A) PHOTOGRAPHS FROM OUTER SPACE
B) SHIPS APPEAR TO SINK PAST THE HORIZON
C) EQUAL STRENGTH OF GRAVITY AT SEA LEVEL
ALL OVER THE EARTH’S SURFACE
D) SPHERICAL SHADOW CAST DURING AN
ECLIPSE OF THE MOON
4) CIRCUMFERENCE OF THE EARTH
A) ERATOSTHENES (TEXT PG. 19)
CALCULATED THE CIRCUMFERENCE OF THE
EARTH ABOUT 2000 YRS AGO
HIS CALCULATION WAS 46,250 MILLION
SQUARE KM
THE ACTUAL CIRCUMFERENCE IS ABOUT
40,000 MILLION SQUARE KM
ERATOSTHENES PERCENT DEVIATION WAS
16%
B) TOTAL SURFACE AREA OF THE EARTH IS 510
MILLION SQUARE KM
WATER = 361 MILLION SQUARE KM
LAND = 149 MILLION SQUARE KM
II
71%
29%
SPHERES OF THE EARTH
1) EARTH IS MADE UP OF A SERIES OF SPHERES
HELD TOGETHER BY GRAVITY
A) ARRANGED FROM LOWEST TO HIGHEST
DENSITY
2) OUTER SPHERES OF THE EARTH
A) ATMOSPHERE - THE LAYER OF GASES THAT
SURROUNDS THE EARTH ABOVE THE SURFACE
COMPOSED MAINLY OF NITROGEN AND
OXYGEN
HUNDREDS OF KM THICK
FARTHEST FROM THE EARTH’S CENTER
BECAUSE IT IS THE LEAST DENSE
STRATIFIED INTO LAYERS OR ZONES EACH
WITH ITS OWN DISTINCT CHARACTERISTICS
TROPOSPHERE, STRATOSPHERE,
MESOSPHERE, THERMOSPHERE
THE BOUNDARIES BETWEEN LAYERS ARE
CALLED PAUSES
B) HYDROSPHERE - THE LAYER OF LIQUID
WATER THAT LIES BETWEEN THE
ATMOSPHERE AND MOST OF THE
LITHOSPHERE
COVERS 70% OF THE EARTH’S SURFACE
AVE 3.8 KM IN THICKNESS
MOSTLY HYDROGEN AND OXYGEN
C) LITHOSPHERE - LAYER OF ROCK WHICH
FORMS THE SOLID OUTER SHELL
APPROX. 100 KM THICK
DIVIDED INTO LITHOSPHERIC PLATES
3) EARTH’S INTERIOR - REGION EXTENDING FROM
THE SOLID PART OF THE EARTH’S SURFACE TO
THE EARTH’S CENTER
A) INCREASING TEMP. AND DENSITY WITH DEPTH
III LATITUDE AND LONGITUDE
1) LATITUDE- THE ANGULAR DISTANCE NORTH
OR SOUTH OF THE EQUATOR
2) EQUATOR- MARKS THE MIDDLE LOCATION ON
EARTH’S SURFACE, HALFWAY BETWEEN THE
GEOGRAPHIC NORTH AND SOUTH POLES
A) PARALLELS OF LATITUDE CONSISTS OF ALL
POINTS HAVING THE SAME LATITUDE
LIEING ON A CIRCLE WHICH IS PARALLEL
TO THE EQUATOR
B) LATITUDE INCREASES TO A MAXIMUM OF
90* NORTH AND SOUTH OF THE EQUATOR
3) WHEN WRITING A LOCATION’S LATITUDE YOU
MUST INCLUDE AN “N” OR AN “S”
4) THE ALTITUDE OF POLARIS EQUALS THE
DEGREE OF LATITUDE IN THE NORTHERN
HEMISPHERE
A) ALTITUDE OF POLARIS AT THE
EQUATOR= ___0*____
NORTH POLE= __90*_____
5) LONGITUDE- IS AN ANGULAR DISTANCE EAST
OR WEST OF THE PRIME MERIDIAN
6) PRIME MERIDIAN- THE MERIDIAN OF ZERO
LONGITUDE WHICH PASSES THROUGH
GREENWICH, ENGLAND
A) MERIDIAN OF LONGITUDE- A SEMI-CIRCLE
ON THE SURFACE OF THE EARTH
CONNECTING THE NORTH AND SOUTH
POLES
B) LONGITUDE INCREASES EAST OR WEST OF
THE PRIME MERIDIAN TO 180*
7)
WHEN RECORDING A LOCATION’S LONGITUDE
YOU MUST INCLUDE EITHER “E” OR “W”
8) YOU MUST BE ABLE TO ACCURATELY READ OR
PLOT ANY LOCATION USING THIS COORDINATE
SYSTEM