Many laypeople seeking land surveying in Idaho may consider “north” to be a static concept. After all, it appears clear on maps, and every smart phone on the market contains a compass that can point you north. However, in order to provide accurate surveys, north literally needs to be considered from every angle, which is why there are four “norths.” What you see as north on a flat map is not the same when you are on site assessing boundaries, easements and topography. Here are the four norths and how they factor into surveys:
- True North: When asked about north, this is what immediately comes to the minds of our clients. True North is the direction towards the North Pole, which is technically defined as the point where all lines of longitude intersect in the northern hemisphere. You will see True North in the key of maps and globes. Since True North is not detectable by compasses or other devices, this is an abstract concept often used more for descriptive purposes. It is meant to give an idea rather than provide firm data.
- Magnetic North: Technically, this is the real True North because it can be objectively verified. Magnetic North is the north indicated on a compass. While this is considered scientific evidence of north, readings will vary by location and even time of day. Changes in the Earth’s core and electrostatic forces can change the location of Magnetic North, making this a very useful estimate that is by no means absolute.
- Grid North: This is another mapping concept not too unlike True North, but with more exact information. The name describes the grid lines on maps that will determine the four directions. Grid North contains a terminus at the South Pole and creates grid lines that continue in the direction of the Prime Meridian, which is the vertical line that crosses the equator at zero degrees. It is a very technical concept normally only useful to land surveyors and mapping professionals.
- Assumed North: While the other north concepts tend to be fairly universal, this one is oriented to place. This is north as related to a subject reference point. It is most easily described by example. If there is an east-west line that runs along the edge of a property boundary, a line directly perpendicular to this boundary is described as assumed north. It will be different in every survey, so an assumed north for your project will not match one conducted for another client.
North is a flexible concept that depends on several variations. Using it accurately depends on direction and point of reference, making it impossible to get a complete survey unless all four of these perspectives are considered. Geology, topography and the very nature of the Earth necessitate slight adjustments when assessing direction and completing surveys.
When it comes to planning projects or making purchases, the accuracy of your survey can make or break your transaction. That is why it is important to find land surveyors known for being thorough and accurate. For experienced land surveying in Idaho, contact Mason & Stanfield, Inc. Call us today to schedule your survey.