Is There Salt in a Glacier?

Overview

For this experiment, we are going to melt dirty ice (ice with lots of sediment/dirt in it) and clean ice (ice without sediment) from the Taylor Glacier. After we melt the ice, we are going to test the melt water for pH and conductivity, and then determine how much salt is actually in our ice samples. There are two ways that you can do this activity: 1) Watch the video clip of our team performing the experiment in the field (see Resources section) or 2) Make your own ice cubes with varying amounts of salt and have your students do the tests.

Objectives

1. All students should be able to describe pH and conductivity and how they are used to measure the amount of salt in a substance.
2. All students should be able to identify whether there is more salt in clean or dirty glacier ice and identify where those salts come from.

Lesson Preparation

Prior to the lesson there are several concepts that might help the students better understand what is going on. The basic knowledge of what a glacier is and how they form would be helpful. A prior investigation (see pre-lab questions) of pH and conductivity measurements and what they tell us about a substance would also help.

Procedure

Describe the steps needed to complete the lesson. For the Teacher: 1. Prepare ice samples the day before, adding varying amounts of sediment and salt to create dirty and clean ice samples. 2. Gather materials for the student experiment. 3. Follow the directions on the student handout.

Extension

n/a

Resources

Video and pictures of experiment done in the field: http://www.polartrec.com/expeditions/microorganisms-in-antarctic-glacier-ice/journals/november-3-2009-is-there-salt-in-a-glac

Assessment

See questions on student handout.

Credits

Lindsay Knippenberg. PolarTREC 2009. lknippenberg [at] solake.org