Mention any 2 major features of maridians. Explain with help of diagrams
Answers
Answer:
line which are horizontals called maridiams
LINES OF LATITUDE -
The lines running east to west, parallel to the Equator are called lines of latitude. A latitude is marked in degrees, with the Equator being 0 degrees. Latitudes are expressed in minutes (') and seconds (''). These lines show us the width of the map. Every latitude must be designated with direction- N for 'north' or S for 'south.' Equator is the largest among all the latitudes
DEFINE GEOGRAPHIC GRID -
The geographic grid is a system designed to pinpoint any location on Earth by laying a vertical and horizontal grid over the Earth's layout. The vertical lines are called the longitude and the horizontal lines are the latitude. The intersection of these two points determines any exact location.
NATURE OF LATITUDE AND LONGITUDE IN TERMS OF X-AXIS AND Y-AXIS -
The grid on the globe serves the same purpose as does the system of coordinates on the x-axis and y-axis on a graph paper. In this case, the x-axis is represented by lines of latitude and y-axis by lines of longitude.
CHARACTERISTICS OF LINES OF LATITUDE -
Lines of latitude run east-west but provide north-south locational reference. Since the lines of latitude are parallel to the equator and each other, they are called parallels of latitude. They are numbered from the equator which is the 0-degree line of latitude. The equator divides the world into northern and southern hemispheres. Only one line of latitude, i.e., the equator is a great circle.
MAIN LATITUDES -
The seven important lines of latitude are the equator at 0 degrees, Tropic of Capricorn at 23.5 degrees south, Tropic of Cancer at 23.5 degrees north, Antarctic Circle at 66.5 degrees south, Arctic Circle at 66.5 degrees north, the South Pole at 90 degrees south and the North Pole at 90 degrees north.
THE NORTHERN AND SOUTHERN HEMSIPHERE -
The Northern Hemisphere is the half of Earth that is north of the equator. It has about 90 percent of world's population and most of the world's land. All of North America and Europe are in the Northern Hemisphere.
The Southern Hemisphere contains all or parts of five continents, including all of Antarctica, Australia, almost all of South America, the southern third of Africa and some southern islands in Asia (parts of Indonesia). Compared to the Northern Hemisphere, the Southern Hemisphere has fewer land masses and more water.
USES OF LATITUDES -
Latitudes give us the location of a place north or south of the Equator. Such a location is known as absolute location. Latitude lines, which run horizontally around the Earth, allow mariners and pilots to know how far north or south they are from the equator. We can measure the distance of any place from the Equator based on its degree of latitude.
LINES OF LONGITUDE -
Longitudes show us the length or height of a map. A longitude is the angular distance of a place east or west of the Prime Meridian. The longitude that passes through the astronomical observatory at Greenwich, England is called the 0
∘
C meridian, Prime meridian or Greenwich meridian. The lines of longitude are also called Meridians of Longitude.
LOCAL TIME -
The local time of any place is obtained by the overhead sun at noon. For each degree of longitude, the local time varies by 4 minutes. For eg. the longitude of Mumbai is 73
o
E and that of New Delhi is 77
o
E. If it is 12 noon at Mumbai it must be 16 minutes past 12 in New Delhi at the same time. (77
o
E - 73
o
=4
o
longitude difference. 1
o
longitude =4 minutes, 4
o
longitude =16 minutes which is added to Delhi because it lies to the east of Mumbai.)
TIME ZONE AND STANDARD TIME - SHORTCUT
The earth has been divided into 24 time zones according to the number of hours in a day. Each zone covers 15
o
longitude (360 ÷ 24) . Countries like India with smaller east-west extent have only one Standard Time Zone, while countries like Russia, USA, Canada have more than one Time Zones.
The uniform time based on a central meridian is known as the Standard Time. Standard time must always be divisible by 7
2
1
o
.
GREENWICH MEAN TIME & INDIAN STANDARD TIME (IST) -
The time at Greenwich has been selected as the mean time. the time fixed with reference to Greenwich is called Greenwich Mean Time or GMT.
In our country, 82
o
30'E is the central meridian which passes through a place near Allahabad. While fixing the Indian Standard Time with respect to the Greenwich Mean Time, we have to add 82
o
30' x 4 minutes = 330 minutes or 5 and a half hours which means India is 5 and a half hours ahead of GMT.
INTERNATIONAL DATE LINE -
The line of longitude 180
o
is one and the same for East or West of the Prime Meridian.The International Date Line is the 180
o
line. When crossing this date line from the west to east, a day is deducted or the time is fixed backward by one day. When crossing the IDL from east to west, a day is added, or the calendar is fixed one day ahead.
