Measuring the Earth

 About 15 billion years ago there was a cosmic explosion.  Dust and debris from this explosion formed into a swirling cloud.  As the cloud spun faster, the debris was pulled in toward the center.

 So much pressure built up that a nuclear reaction occurred…The SUN is born!

 Remaining dust in the cloud began to clump together forming protoplanets. OUR SOLAR SYSTEM WAS BORN!

 Earth was molten when it first formed.

There was intense volcanism during Earth’s formation…

Steam from volcanic eruptions eventually cooled and condensed into water

 Outgassing from volcanic activity led to the formation of Earth’s atmosphere.

 The secret ingredients of life: methane, ammonia, nitrogen, carbon dioxide, and water  + a POWERFUL energy source (LIGHTENING!)

 Chemical reactions were triggered that led to the formation of basic organic molecules like amino acids.  (Amino acids make proteins…proteins make LIFE). Miller/Urey

 Earth’s molten surface began to cool and solidify into rock.

 Earth’s different materials began to settle out according to density. The most dense sank to the center and the least dense rose to the surface.

The Shape of the Earth

4. The altitude of Polaris (the North Star) changes as you move north or south in latitude. (We will discuss latitude in more detail very soon)

 WHAT IS THE ACTUAL SHAPE OF THE EARTH? 1. Earth is NOT a perfect sphere. It is very slightly wider at the equator. This shape is called an oblate spheroid. 2. The bulge at equator is partially due to Earth’s rotation upon its axis. (Speed of rotation is appx mph at Equator and at the North Pole there is almost no speed at all.) 3. Earth’s circumference: Equator: 40,076 miles Poles: 40,008 miles

 Which diagram most accurately shows the cross-sectional shape of the Earth drawn to scale?  (1)`(2)  (3)(4)

EARTH’S THREE SPHERES

The Earth’s Crust A thin shell of rock covering the planet ~.3 – 30 miles thick

 Layer of water which rests on the lithosphere.  Covers 70% of Earth’s surface.  Thinnest of all layers.

 Shell of gasses that surround the earth.  Layered Zones: Troposphere, Stratosphere, Mesosphere

 CAN YOU GUESS WHICH LAYER(S) IT IS?

 BRAINPOP "THE ATMOSPHERE" BRAINPOP "THE ATMOSPHERE"

Layers of the Earth Reference tables page 10

Layers of the atmosphere Reference Tables page 14

Longitude and Latitude

 Mapmakers have developed a grid system (lines based on the concept of and X and Y axis) that can be used to identify any position on Earth.  This is called a coordinate system.  We will call these coordinates TERRESTRIAL COORDINATES.  This system assigns a pair of numbers (coordinates) which are based on latitude and longitude.

Latitude is measured north and south of the equator.

 It divides the globe into a northern and southern hemisphere  It is the main reference point for measuring latitude.

The highest degree of latitude is 90 o 90 o NORTH is the North Pole 90 o SOUTH is the South Pole. Lines of latitude are called PARALLELS. Lines of latitude measure the globe from North to South…think of climbing the rungs of a ladder.

Longitude is measured EAST and WEST of the Prime Meridian.

Highest degree of Longitude is 180. (Opposite side of the globe from the Prime Meridian. Int’l Date Line) Lines of longitude are also called MERIDIANS. They cut the globe into the Eastern and Western Hemisphere. They measure the globe from east to west. The meridians converge at the poles. They are NOT parallel.

Which type of line measures north and south? What is the name of the main line that divides the globe into the Northern and Southern Hemisphere? Which type of line measures east and west? What is the name of the main line that divides the globe into the Eastern and Western Hemisphere?

EXAMPLE: 45 o N, 15 o E What does this mean? Things to remember: You always write Latitude first, then Longitude You must always put a compass direction next to your degrees to indicate which hemisphere you’re in.

 40 o N  This means your latitude is 40 degrees North of the Equator. You must either find that line of latitude or INFER where it is based on the other lines of latitude indicated. (They are very often written in either 15 or 30 degree intervals).  15 o E  This means your longitude is 15 o East of the Prime Meridian.

FIND YOUR LONGITUDE 

NYS Map in Reference tables

BRAINPOP on Latitude and Longitude Degrees are divided in to minutes and minutes are divided into seconds. Each degree has 60 minutes Each minute has 60 seconds. These degrees are measurements of ANGLES…not temperature! Latitude and Longitude clip 3 mins YOUTUBE

 Polaris is the “North Star”  Located directly (90 degrees) above the North Pole

 The angular elevation of Polaris above the horizon is equal to the observer’s latitude. ALTITUDE = LATITUDE

 If you know your latitude, you know how high in the sky to look for Polaris!

 Altitude of Polaris ANIMATION Altitude of Polaris ANIMATION

1. Wait for a clear night 2. Get to a location with an unobstructed view of the sky. 3. Face yourself towards the North 4. Look up…...

 Locating Polaris ANIMATION Locating Polaris ANIMATION

Try This! The altitude of Polaris is 41 o 32’ in Rye. What is Rye’s latitude? 41 o 32’ N

Try This! The altitude of Polaris is 47 o 21’ in Zurich, Switzerland. What is Zurich’s latitude? 47 o 21’ N

Try This! The Latitude of Sao Paolo, Brazil is 23 o 31’ S. What is the altitude of Polaris in the sky above Brazil? You can’t see Polaris in the southern hemisphere.

Time Zones

 The Earth is divided into 24 different time zones. (24hrs/day = 24 time zones)  They are based on longitude and Earth’s rotation on it’s axis.  15 degrees longitude = 1 hour time difference.  (360 o /24hr = 15 o /hr) THINK! What kind of equation have we just solved?

 Sunlight moves from East to West during the course of the day causing day and night.  Places that have the same longitude will be in the same time zone. (Time doesn’t change as you move north or south.)longitude  Time only changes as you move east or west.  As you move eastward, time gets later  As you move westward, time gets earlier.

 Greenwich Mean Time  The starting point for measuring all time worldwide  The time at the Prime Meridian is called GMT.  (Sometimes called Universal Time)  BTW!!! Be familiar with the term SOLAR TIME! It just means…what time it is in a certain location based on the sun’s location and the earth’s rotation.

 The time-zone process began in 1883 for the United States, when the nation was divided into four standard time zones. Each zone was centered on a meridian of longitude:  Eastern Standard Time (EST) at 75 degrees W (west of the Prime Meridian)  Central Standard Time (CST) at 90 degrees W  Mountain Standard Time (MST) at 105 degrees W  Pacific Standard Time (PST) at 120 degrees W

 180 degrees East or West of the Prime Meridian.  Crossing from the W Hemisphere to the E. Hemisphere you ADD A DAY. (Thursday becomes Friday)  Crossing from the E. Hemisphere to the W. Hemisphere you subtract a day. (Friday becomes Thursday).

EASTERN HEMISPHERE WESTERN HEMISPHERE

 BrainPop Time Zones BrainPop Time Zones

12 Noon on the Prime Meridian (Greenwich) -If the location time is earlier than Greenwich, the longitude is west -if the location time is later than Greenwich, the longitude is east.

-If the location time is earlier than Greenwich, the longitude is west -if the location time is later than Greenwich, the longitude is east. Do Now: It is 5 hours earlier in Rye, N.Y. than it is in Greenwich (O o longitude). What is Rye’s longitude? 5 hours x 15 o per hour = 75 o West Longitude

-If the location time is earlier than Greenwich, the longitude is west -if the location time is later than Greenwich, the longitude is east. Do Now: Los Angeles is 8 hours earlier than Greenwich (O o longitude). What is LA’s longitude? 8 hours x 15 o per hour = 120 o West Longitude

-If the location time is earlier than Greenwich, the longitude is west -if the location time is later than Greenwich, the longitude is east. Do Now: It is 9 hours later in Tokyo than it is in Greenwich (O o longitude). What is Tokyo’s longitude? 9 hours x 15 o per hour = 135 o East Longitude

 Fields and Mapping

 A field is a region in space in which there is a measurable quantity at every point. (Ex. Temperature, Elevation)  A map that shows these measurements is called a field map.

 A field is a region in space in which there is a measurable quantity at every point.  Examples: Temperature, wind, gravity, radiation  2) Types of fields:  Scalar = needs only a number (temperature)  Vector = needs number and direction (wind)

 Field Maps  --maps with field values. All equal numbers are connected with lines, called isolines.  Types of isolines:  isotherms = lines of equal temperature

 Field Maps can look really random and confusing. So we try to make sense of them by showing patterns in the recorded data.  All equal numbers are connected with lines, called isolines.  ISO means EQUAL isotherms = lines of equal temperature  isobar = lines of equal pressure

3) Field Maps 4) --maps with field values. All equal numbers are connected with lines, called isolines. 4) Types of isolines:  isotherms = lines of equal temperature  isobar = lines of equal pressure  contour lines = lines of equal elevation

 Topographic maps-  (contour maps)  - show the shape of the Earth’s surface.

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 Topo map rules:  There is a contour interval –  -difference in elevation between contour lines

 Topo map rules:  There is a contour interval –  -difference in elevation between contour lines  2) Contour lines make a “V” shape where a river crosses them. The “V” always points upstream (opposite the way the river is flowing).

 Topo map rules:  There is a contour interval –  -difference in elevation between contour lines  2) rivers make a “V” shape. The “V” always points upstream (opposite the way the river is flowing).  3) contour lines NEVER touch!

 gradient-  -how steep a slope is:  lines close together = steep gradient  lines far apart = gentle gradient