6.1.9 Hardness, 2
The more formal way of determining hardness is to use a ram penetrometer, which measures resistance as it is thrust into the snowpack layer. The greater the resistance, the greater the layer’s degree of hardness.
Here’s a hardness profile obtained with a ram penetrometer.
What do you think the thin layer near the top of the snowpack consists of? Select the correct answer(s), then click Done.
The correct answers are b and c.
Penetrometer resistance is very high for the thin layer, indicating that the grains are tightly bonded and likely to be crust. It could also be a buried dirt layer, since these often form hard ice layers. It cannot be depth hoar or low-density grains; these have a low degree of bonding, which makes them easy to penetrate.