Abstract

Three simple activities can be used to help students understand the internal and external processes that take place when glaciers advance. Students will learn that in addition to gravity pulling glaciers downhill, other processes are concurrently taking place: deformation, melting and refreezing, weathering and erosion. The following hands-on activities, inserted at different intervals during the class lecture, introduce students to these processes. First, students explore how glacial melting and refreezing can be caused by pressure. Students embed a toothpick and a piece of plastic straw into ice by applying pressure to the items, then releasing the pressure to allow the meltwater to refreeze around the items. Next, the students use two dots and a straight line drawn on "glacier putty" to observe the how friction causes different parts of the glacier to move at different velocities. Finally, students simulate glacial plucking using putty and craft beads. At the end of the class session, students will understand that glaciers are not simply large blocks of ice that slide downhill due to gravity. They will know how glaciers move and deform, and understand one way that glaciers remove and transport rocks during advancement.

Context

These activities are used in introductory level geology courses that do not have a lab. These courses are taken by non-majors in order to earn science general education credits.

Why It Works

These activities address concepts that seem foreign to many students because many have never seen glaciers. As a result, many glacial concepts involving the ice movement, deformation, and erosion seem abstract. These activities provide concrete visualization of glacial processes which helps students understand the behavior of glaciers more completely.