13 Showcase of Undergraduates (Posters)

Monday, 24 March 2003
5:00 PM - 9:00 PM

IT'S GETTING COLD IN HERE! TEACHING MATHEMATICS AND GLACIOLOGY TO HIGH-SCHOOL STUDENTS USING ABLATION MEASUREMENTS FROM THE MATANUSKA GLACIER, ALASKA

Program: THEME SESSIONS
Time: 5:00 PM – 9:00 PM

Authors

Abstract

This project presents new data to test the effects of weather and debris mantle on hourly ablation rates at the Matanuska Glacier in south-central Alaska. The data is combined with a visual glossary of glacial landforms and processes to create a graphing module for use with a glacial geology lesson plan for a secondary earth science course. Rates of melting vary throughout the course of a day, depending on factors such as air temperature, incoming solar radiation, cloud cover, wind speed and direction, and debris cover. Therefore, ablation data is a useful tool for teaching graphing techniques, hypothesis testing, and glaciological processes. Students will be asked to interpret graphs that they will prepare using this data. Using inquiry based learning, the students will need to decide which of the many factors has more influence on ablation and why this is so. This lab will help the students in their graphing skills as well as their deductive reasoning skills. The glossary, which will include terms that students may not be familiar with, will help the students understand more about glaciers and their processes.

Melt rates of glacier ice were determined by the installation and monitoring of 12 ablation stakes (pvc pipe) in three plots near the glacier terminus. Stakes were located in clean glacier ice, partially debris-covered ice, and fully debris-covered ice to test the effects of debris mantle on hourly ablation rates. Ablation was measured during a period of two weeks. Measurements for this experiment were taken between the hours of 10:00 am to 4:00 pm during sunny, cloudy, and partly cloudy days. Average hourly ablation rates were 2.9 mmh-1 in clean ice, 3.1 mmh-1 in partially debris-covered ice, and 2.7 mmh-1 in fully debris-covered ice. A second experiment was conducted in which we measured hourly ablation during two twenty-four periods. By comparison, ablation measured hourly during a sunny period melted at an average rate of 3.1 mmh-1 (3.6 mmh-1 during the hours of 10:00am to 4:00pm) compared to an average rate of 1.8 mmh-1 (2.2 mmh-1 during the hours of 10:00 am to 4:00pm) during a rainy period. While the debris cover does affect the hourly ablation rate, the weather is a larger contributor. There is a maximum difference in melting rates of 0.4 mmh-1 between the two debris-mantled areas while there is a 1.3 mmh-1 difference in the melting rates of sunny versus rainy weather.