Presented to : Sir EngrLATIF JANPresented by : NIK JAMALID : 5370

Meridian Equator, Latitude and longitude

IQRA NATIONAL UNIVERSTY

Contains What is the Prime Meridian?What is the Equator ?What is the Latitude?What is the longitude? What are the North and South Latitudes?What are the East and West Longitudes?The International Date Line.

What is Latitude?

• Latitude is defined as a measurement of distance in degrees north and south of the equator• The word latitude is derived from the Latin word, “latus”,meaning “wide.”

What is Latitude?

There are 90 degrees of latitude from the equator to each of the poles, north and south.

Latitude lines are parallel, that is they are the same distance apart

These lines are sometimes referred to as parallels

The Equator

The equator is the longest of all lines of latitude

It divides the earth in half and is measured as 0° (Zero degrees).

North and South Latitudes Positions on latitude lines above the equator are called “north” and are in the northern hemisphere.

Positions on latitude lines below the equator are called “south” and are in the southern hemisphere

What is Longitude? Longitude is defined as measurement of distance in degrees east or west of the prime meridian.

The word longitude is derived from the Latin word, “longus”, meaning “length.”

What is Longitude?

The Prime Meridian, as do all other lines of longitude, pass through the north and south pole.

They make the earth look like a peeled orange.

East and West Longitudes

Longitude lines to the left of the prime Meridian give locations west, in the western hemisphere.

Longitude lines to the right of the primer meridian give locations east, in the eastern hemisphere.

Latitude -Longitude

•Latitude lines are the horizontal circles drawn on a globe. •The starting latitude is 0o and is known as the Equator. •Latitude is always the first point plotted and will always be listed as how many degrees North OR South of the Equator that point lies. •Keep in mind that the two extreme latitudes are the North Pole (90oN) and the South Pole (90oS).

The Prime Meridian

The Prime meridian divides the earth in half too.

It is also 0°. It passes throughthe community of Greenwich, England.

The International Date Line

There are 180 lines of longitude on each Side of the prime meridian.

But on the opposite side, the primer meridian is not zero degrees but 180°.

It is called the International Date Line.

Latitude -Longitude

•Longitude lines are the vertical circles drawn on a map. •The starting longitude is 0o and is known as the Prime Meridian. This meridian is defined as the longitude line that starts at the North Pole, travels through Greenwich, England, and ends at the South Pole. •Longitude is always the second point plotted and will always be listed as how many degrees West or East of the Prime Meridian that point lies. •Keep in mind that the extreme longitude is 180o and is called the International Date Line.

Latitude -Longitude

•A mercator projection is a flat version of the globe •Much easier to work with •Locations toward each pole (eg. Greenland, Antarctica) appear larger than reality due to “stretching”

Latitude -Longitude

•When locating points that lie between two adjacent latitudes or longitudes (ex. between 41oN and 42oN) a smaller unit is desired. •A degree of spacing is made up of 60 smaller units called arcminutes. One degree is equal to 60'. Therefore, fractions of a degree are equal to some number of arcminutes. For example, ½ degree equals 30', ¾ degree equals 45’, and so forth.

Latitude -Longitude

•The distance that separates one latitude degree from another (ex. between 41oN and 42oN) can be given as 60 nm (nautical miles) or 69 mi (statute miles).•Ex: the distance between 23oS and 25oS is two degrees. There are 120 nm (2 x 60) or 138 mi (2 x 69) between these two points.•Keep in mind that the relationship of 1 degree = 60 nm or 69 mi only works for latitudes because longitude line spacing is not constant. Meridians of longitude narrow as one moves pole ward.

Latitude -Longitude

•The rotation axis of earth is “tilted” 23.5o from vertical•This tilt is what causes seasons

Latitude -Longitude

•Solstices are times of the year when the noon sun angle is highest or lowest•Equinoxes are times of the year when the vertical rays of the sun strike the equator at noon. There are 12 hours of day and night for all locations

Latitude -Longitude

•Solstices are times of the year when the noon sun angle is highest or lowest

Latitude -Longitude

•Blue curve represents the latitude where the sun’s vertical rays strike the Earth•Key locations:•Equinoxes: 0o (Equator)•Summer Solstice: 23.5oN (Tropic of Cancer)•Winter Solstice: 23.5oS (Tropic of Capricorn)

Latitude -Longitude

• Noon Sun Angle (SA) = 90o – N where N = Distance in latitude between Observer and Sun’s vertical rays

• Ex: What is the sun angle for a Selden observer (41oN) on the summer solstice? Sun’s vertical rays strike 23.5oN on summer solstice. Therefore,

• N = 41o - 23.5o = 17.5o• SA = 90o – 17.5o = 72.5o • Ex: What is the lowest possible noon sun angle for a Selden

observer? Sun’s vertical rays are farthest south and strike 23.5oS on winter solstice. Therefore,

• N = 41o + 23.5o = 64.5o • SA = 90o – 64.5o = 25.5o