Snow Pit Stratigraphy
PLEASE do not be dissuaded from this exercise because it is written for a specific location. The ideas can be translated anywhere there is snow and the snow does not have to be exceptionally deep.
Skills and concepts that students must have mastered
How the activity is situated in the course
Content/concepts goals for this activity
- Observation of snow
- Description of snow
- Work with a snow cover sheet
- Interpret data
- Observe, describe and record snow stratigraphy, density, hardness, temperatures, temperature gradients and crystals within a snow pit, and study the effects of snow metamorphism.
- Calibrate your finger hardness force. Push on your cheek toward your teeth with your finger (no pain) or push on the tip of your nose (no pain). (North American Standard is 10-15 N force; International Standard is 50 N force.)
- Determine how consistent the stratigraphy is from location to location. Are there trends from pit to pit at the site?
Higher order thinking skills goals for this activity
- Collect data
- Analyze data
- Test hypothesis presented to the students
Other skills goals for this activity
- Write about the results in a scientific format
- Work in groups
Description of the activity/assignment
The student understands that snow leads to avalanches, but is often very inexperienced in the observation of the snow pack. This exercise provides the opportunity to learn about snow stratigraphy, observation, and measurement from a detailed observational perspective. The students work in small groups in 3-6 pits (depends on the class size). By working on a transect from the trees out into the opening, they discover (usually) that the snow depth is different and that the descriptions in the pits differ as one proceeds out from the trees into the opening. (Different stratigraphic units, different thickness, different temperature, different density, different crystals.)
Determining whether students have met the goals
Teaching materials and tips
- Excel Grading Rubric (Excel 17kB May17 10)
- The International Classification for Seasonal Snow on the Ground - Issued by the International Commission on Snow and Ice of the International Association of Scientific Hydrology and Co-Issued by the International Glaciological Society (I prefer this to the 2010 classification cited next).
- The International Classification for Seasonal Snow on the Ground from the International Association of Cryospheric Sciences. The revised International Classification for Seasonal Snow on the Ground has been published 2009 by the International Hydrological Programme of the United Nations Educational, Scientific and Cultural Organization (UNESCO-IHP), Paris, in the series of IHP Technical Documents in Hydrology: IACS Contribution.
- Snow, Weather, and Avalanches: Observational Guidelines for Avalanche Programs in the United States, from the American Avalanche Association. There is a new version of this book but it is not available online at the time of this writing.
- Many References on the student handout for the activity (HTML File 15kB May17 10).
- A simpler conceptual guide is presented in:
Custer, S.G., 1991, Snow as a field-teaching medium for Earth Science: Journal of Geological Education, v 39, p. 34-43.