Can a Shadow Stick Help Determine Elevation Changes in Terrain?

Creating a Shadow Stick

A shadow stick is a simple, yet effective navigation tool made from a straight branch or stick. To create a shadow stick, select a stick that casts a clear, distinct shadow when held vertically. Hold the stick vertically at eye level, note the direction of the shadow, and observe how it changes as the sun moves. This technique is most effective when the sun is moving in a straight line across the sky.

Using the Shadow Stick to Measure Elevation

To measure elevation changes using a shadow stick, you need to understand how to interpret the changing shadow. When the shadow is short, the sun is high in the sky, indicating a relatively flat terrain. As the sun moves lower, the shadow lengthens, and the terrain may be sloping upwards. Conversely, when the shadow shortens, the terrain may be sloping downwards. For example, if the shadow is 10 feet long at 10:00 AM and 5 feet long at 11:30 AM, you can estimate the terrain is rising by approximately 1 unit of elevation change.

Practical Application

To accurately use a shadow stick, take multiple readings at regular intervals, ideally every 30 minutes, to capture the changing shadow. This allows you to plot the shadow’s movement and estimate the terrain’s slope. By understanding how to interpret the shadow stick, you can make informed decisions about navigation, locate potential hazards, and plan routes accordingly. It’s essential to note that this technique requires a relatively clear sky and a straight line of sight to the sun. In overcast or foggy conditions, the shadow stick may not be as effective.