Eastings run along the top of a map Northings run along the left side of a map
23 MAP CONVENTIONS On our searcher maps, Eastings and Northings on BLUE LINES end with an asterisk (*) The asterisk represents three zeros. For example: 481* =
24 MAP CONVENTIONS Eastings increase left to right Northings increase bottom to top
25 MAP CONVENTIONS The numbers on the red lines show only the last three digits of their actual value For example, the 600 circled below represents:
26 CALCULATING GRID REFERENCES Locate the map feature you want to generate a UTM grid reference for. This example uses a 1:10000 scale map.
27 CALCULATING GRID REFERENCES Determine the Easting 1. Measure (in mm) the distance from the BLUE LINE to left of feature to the feature itself. 31 mm
28 CALCULATING GRID REFERENCES Determine the Easting 2. Add a zero to the end of the measured distance of 31 mm: 310
29 CALCULATING GRID REFERENCES Determine the Easting 4. Locate the value of the BLUE LINE to the immediate left of the feature. 481*
30 CALCULATING GRID REFERENCES Determine the Easting 5. Replace the * in 481* with the (310) to give the Easting:
31 CALCULATING GRID REFERENCES Determine Northing 1. Measure (in mm) distance from the BLUE LINE below the feature to the feature itself. 26 mm
32 CALCULATING GRID REFERENCES Determine Northing 2. Add a zero to the end of the measured distance of 26 mm: 260
33 CALCULATING GRID REFERENCES Determine Northing 4. Locate the valueof the BLUE LINE below the feature. 4952*
34 CALCULATING GRID REFERENCES Determine Northing 5. Replace the * in 4952* with the 260 to give the Northing:
35 CALCULATING GRID REFERENCES Putting the Easting and Northing together, you get the UTM grid reference for the School: E N
36 UTM GRID REFERENCE EXERCISE Using the provided 1:10000 Searcher s map, determine the grid references for the following: A) SCHOOL. B) ESGSAR BUS. C) CAMP. D) Waypoint #4.
37 UTM GRID REFERENCE EXERCISE ANSWERS A) SCHOOL: E N B) ESGSR BUS: E N C) CAMP: E N D) Waypoint #4: E N
38 DATUMS Map grids are based on a series of accurately surveyed points called datums, to ensure that the grids are consistent on all maps. Newer Nova Scotia maps use the NAD83 datum. Using the wrong datum can result in grid references being off by hundreds of meters.
39 DATUMS When entering grid references into a GPS, the user must ensure the datum of the GPS is set to the datum of the map. Map datums are located on the bottom margin of the map. Nova Scotia GSAR teams use the NAD83 datum.
40 MAJOR MAP DIVISIONS Topographic maps have three major divisions: Vegetation Water Relief
41 Relief Vegetation Water Example of Major Map Divisions
42 MAP SYMBOLS Symbols are used on maps to represent features on the ground. The key to these symbols is either on the reverse side of the map or in the margin. All map symbols on Canadian topographic maps conform to the following colour code: Black: human-made features Blue: water Green: forest or vegetation Brown: elevation (contours) White: open areas, field or snowfield Red: highways Orange: secondary or dirt roads Pink: high population density areas Purple: updated data
43 Sample map symbols
44 Sample map symbols
45 Sample map symbols
46 Sample map symbols
47 Sample map symbols
48 Sample map symbols
49 TOPOGRAPHIC CONTOURS On topographic maps elevation is indicated with Contour Lines. A contour line on a map is a line that connects points of equal elevation above sea level. The vertical distance between two contour lines is the Contour Interval (C.I.). The contour interval is located on a map s margin.
50 TOPOGRAPHIC CONTOURS The contour interval for ESGSAR searcher maps is 10 meters. Contour lines are usually drawn with reference to sea level. On most topographic maps, every fifth contour line is printed darker for easy recognition and is locally labelled with its elevation. These are called Index Contours.
51 CONTOUR LINE RULES 1. All points on the same line are at the same elevation. 2. All contour lines close somewhere, although it may be outside the map at hand. 3. Contour lines never cross, except when th