Magnetic Declination and Navigation

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What is Magnetic Declination?

Magnetic Declination is the angle between True North and Magnetic North.

What causes compasses to read Magnetic North?

Compasses read Magnetic North because they are magnetic and align with the Earth's magnetic field.

How can you find Magnetic Declination?

To find Magnetic Declination, subtract or add the smaller number from Magnetic North if it is West or East of True North, respectively.

What is the relationship between Grid North and True North?

Grid North is usually the closest to True North, but not as close as Magnetic North. Signup and view all the answers

How can you determine the direction of stream flow using contour lines?

Contour lines shaped like V's around a stream indicate the direction of stream flow. The point of the V shows the direction. Signup and view all the answers

What is a survey control mark and what information does it provide?

A survey control mark is a specific point on a quadrangle map that provides the exact elevation of a location. Signup and view all the answers

How many graticule tick marks are there on a quadrangle map?

There are 4 graticule tick marks on a quadrangle map. Signup and view all the answers

What are the names of the sectors that the graticule tick marks divide the map into?

The sectors are named as follows: Sector 1 NW, Sector 2 N, Sector 3 NE, Sector 4 W, Sector 5 C (center), Sector 6 E, Sector 7 SW, Sector 8 S, Sector 9 SE. Signup and view all the answers

What information do the graticule tick marks align with on the quadrangle map?

The graticule tick marks align with the latitude and longitude marks on the quadrangle map. Signup and view all the answers

What does the picture in the text show?

The picture in the text shows a benchmark survey marker. Signup and view all the answers

What is the purpose of a benchmark survey marker?

A benchmark survey marker gives the exact elevation of a location. Signup and view all the answers

Why does a survey control mark need to be constantly updated on a mountain?

Because the elevation of mountains changes with tectonic plates. Signup and view all the answers

How many graticule tick marks are there on a quadrangle map?

There are 4 graticule tick marks on a quadrangle map. Signup and view all the answers

What do the graticule tick marks divide the map into?

The graticule tick marks divide the map into 9 different sectors. Signup and view all the answers

What are the names of the sectors that the graticule tick marks divide the map into?

The sectors are: Sector 1 NW, Sector 2 N, Sector 3 NE, Sector 4 W, Sector 5 C for center, Sector 6 E, Sector 7 SW, Sector 8 S, Sector 9 SE. Signup and view all the answers

What information do the graticule tick marks align with on the quadrangle map?

The graticule tick marks align with the latitude and longitude marks on the quadrangle map. Signup and view all the answers

What information do the graticule tick marks show?

The graticule tick marks show the latitude and longitude of a quadrangle. Signup and view all the answers

What is the map below a quadrangle of?

The map below is a quadrangle of East Amarillo. Signup and view all the answers

What is the relationship between a graticule tick mark and a latitude and longitude mark?

The graticule tick marks align with the latitude and longitude marks on the quadrangle map. Signup and view all the answers

What is the purpose of a survey control mark?

A survey control mark gives the exact elevation of a location. Signup and view all the answers

What is the purpose of Magnetic Declination?

The purpose of Magnetic Declination is to determine the difference between True North and Magnetic North. Signup and view all the answers

What is the difference between Magnetic North and True North?

Magnetic North is the direction indicated by compasses, while True North is the actual direction of North. Signup and view all the answers

How can you calculate Magnetic Declination?

To calculate Magnetic Declination, subtract or add the declination angle from the bearing, depending on whether Magnetic North is to the west or east of True North. Signup and view all the answers

What is the relationship between Magnetic North and Grid North?

Magnetic North is usually the farthest from True North, while Grid North is usually the closest to True North. Signup and view all the answers

How can you determine the direction of stream flow using contour lines?

By observing the contour lines shaped like V's around a stream, the direction of stream flow can be determined based on the direction in which the point of the V is facing. Signup and view all the answers

What does the contour line V pointing to the northwest indicate about stream flow?

If the contour line V points to the northwest, it indicates that the stream is flowing to the southeast. Signup and view all the answers

What does the contour line V pointing to the southeast indicate about stream flow?

If the contour line V points to the southeast, it indicates that the stream is flowing to the northwest. Signup and view all the answers

What is the purpose of the declination diagram when calculating Magnetic Declination?

The declination diagram is used to determine whether Magnetic North is to the west or east of True North, and to determine the number of degrees to subtract or add when calculating Magnetic Declination. Signup and view all the answers

What is the significance of the declination angle when calculating Magnetic Declination?

The declination angle is added or subtracted from the bearing in order to adjust for the difference between Magnetic North and True North. Signup and view all the answers

What is the major difference between Magnetic North and True North?

The major difference between Magnetic North and True North is that Magnetic North is based on the direction indicated by compasses, while True North is the actual direction of North. Signup and view all the answers