GRID SYSTEMS

 The most common way to locate a place on a map is to use a GRID system  There are three different grid systems: 1. Alphanumeric Grid 2. Map Grid/Military Grid 3. Latitude and Longitude

Eastings  Run vertically on a grid  They are always written first  Each is identified by a two-digit number(In a six- digit grid it is identified by three digits)  The easting refers to the column to the right of the line

Northings  Horizontal lines that run across a map  The northing refers to the row above the line  By combining the 2 digits of easting/northing we can identify a specific square on the map

1. Alphanumeric Grid  Uses letters and numerals to identify squares in a grid pattern  Grid square are identified by letters along one edge of the map and a number along the other  i.e. A1 (found on road maps, the game battleship)

How to read an Alphanumeric Grid The smiley face is found in box F6

2. Military Grid ex. 4&6-Digit Grid Reference  Any point on a map may be located using a four or six digit number Four Digit Grid  When locating a general location you can use a four digit reference.

Four Digit Reference  The Church in this example is located at 9194  “91” refers to the easting and the Church is located to the right of major reference line 91  “94” refers to the northing (the Church is located above 94)

Four Digit (cont’d)

Six Digit Reference  Each grid square can be divided into tenths.  When given a 6-digit grid reference like this: the last digit in each set measures a specific location within the box

How to read a 6-Digit Reference

Remember… READ RIGHT, READ UP

3. Latitude and Longitude  Latitude:  Is the distance north and south of the equator; measure in degrees  Runs horizontally  Lines run parallel (never touch)  There are 180 lines of latitude  North pole 90 N  South pole 90 S

Longitude:  Is the distance east and west of the Prime Meridian  Half way around the globe is the International Date Line (180 DEGREES)  Runs vertically  Lines meet in the poles  There are 360 lines of longitude

 The Equator:  O degrees latitude  Divides the planet into northern and southern hemispheres

 Prime Meridian:  Is the line of longitude on maps and globes that joins the North and South Poles  0 degrees longitude  Runs through Greenwich, England  Divides the earth into the eastern and western hemispheres

 WHAT QUADRANT OF THE EARTH DO WE LIVE ON? 1. NE 2. SE 3. NW 4. SW ?????????

The answer is… NW