Model = anything that represents the properties of an object Physical Types of models: Globes Mathematical Mental Mechanical Graphic Equations Water Molecule Model train Line Graph E = MC 2

Parts of the Earth The four spheres of Earth…  – the shell of gases that surrounds Earth  – the waters of Earth; (oceans, seas, lakes and rivers)  – the dense, solid outer shell of Earth composed of rock  –“life” Living organisms Atmosphere Hydrosphere Lithosphere Biosphere

Shape of the Earth Oblate Spheroid -   Diagram of an flattened sphere flattened at poles bulges at equator oblate sphere Not to scale!!

 Earth’s equatorial circumference is… than its polar circumference a. Equatorial circumference - b. Polar circumference - greater 40,075 km 40,008 km The difference is only 67 km, that’s about 40 miles!!

Causes of Earth’s Shape – an inward pulling force. This force pulls inward equally in all directions and causes earth to be Gravity spherical

– an outward force caused by the spinning (or rotating) of earth on its axis. This force causes earth to. (The faster the rotational speed, the the inertia, therefore the the bulge.) Inertia bulge greater

Earth Grid Coordinates Latitude- angular distance North or South of the Equator. “ladder-tude” lines of latitude that are horizontal, parallel to the Equator Parallels – 0 o latitude, starting point for measuring latitude Equator – 90 o latitude; max latitude value North / South Pole –

Some important lines of Latitude North pole South Pole Arctic Circle Tropic of Cancer Antarctic Circle Tropic of Capricorn Equator See also: ESRT page 4

ESRT pg 4

The altitude of Polaris is equal to the latitude of the observer. 0o0o 30 o N 60 o N90 o N

Longitude – angular distance east or west of the Prime Meridian Earth Grid Coordinates 0 o longitude, starting point for measuring longitude. Runs through England o Prime Meridian – lines of longitude that “run vertically pole to pole” o Meridians – ~180 o longitude; max longitude value o International Dateline -

Rules for determining latitude & longitude Find location on the map Is the location N or S of the Equator? How far N or S of the Equator is it? (# of degrees) Is the location E or W of the Prime Meridian? How far E or W of the Prime Meridian is it? (# of degrees) Write the coordinates in the order you just found them: °N/S, °E/W. Be sure to include direction (N/S and E/W as well as # value)

Let’s Practice: A – B – C – D – E – 30°N 60°E 30°S 30°W 0° 90°W 45°N 75°W 10°N 25°W

When writing latitude and longitude north can be given a (+) value and south a (-) value; east is given a (+) value, west a (-) value. Practice: A:B: C: A B C 30°, - 105°-20°, 35°-30°, 120°

Degrees of latitude and longitude can be divided into and minutes seconds. Just like 1 hour of time can be divided into 1 degree of latitude and longitude can be divided into 60 minutes, 60 minutes. Just like 1 minute of time can be divided into 1 minute of latitude and longitude can be divided into 60 seconds, 60 seconds. 43.5° N can be written as43°30’ N

42°30’ N 42°15’ N

Earth’s Time Zones The Earth is a sphere - # ° in a circle # hours to make 1 rotation hours = °/ hour Earth’s rotational speed As you move west the hour is earlier ° ÷ 24 15

Field - Isolines – a region that has a measurable value of a given property at every point lines on a field map connecting all points of the same value 10

Topographic Maps Elevation – Contour Line – Index Contour Line – Contour Interval – Depression Contour- isolines on a map connecting points of the same elevation distance (height) above sea level (ft or m) difference in elevation between two adjacent contour lines hachure marks drawn on contour lines to show decreasing elevation heavy dark contour line, usually with a value written on it

Bench Mark –marker in the ground indicating elevation above sea level Spot elevations - Elevations of specific locations shown on a map, such as road intersections, hilltops and points of interest. Often marked with a (+), unless obvious.

Verbal Graphic Fractional

Contour Interval = feet 20 Index Contour Line Contour Line Depression Contour

Gradient – Formula: Slope = rate at which elevation changes from place to place change in field value between 2 points change in field value distance (ESRT pg 1) Steep Slope Gentle Slope

How do contour lines show a steeper slope? What three (3) basic features of a landform do contour lines show?  Lines are closer together elevation gradient shape

Law of “V’s” The “V’s” point! This stream is flowing upstream west to east.

Profile (cross section) of a hill

Contour Mapping Rules 1.All points on a contour line are the same 2.A contour line surrounded by another contour line is than the line that surrounds it (by the contour interval). 3.A contour line between two different contour lines is the same elevation as the contour line. 4.A depression line surrounded by a contour line is the same elevation as the line. 5.A depression line between two different contour lines is the same elevation as the contour line. 6.A depression line surrounded by another depression line is than the surrounding depression line (by the contour interval. 7.Contour lines never or. elevation higher closed higher surrounding contour closed lower cross fork