Playing with Mud: Sediment Deposition by Tidewater Glaciers

Overview

This lesson is based on studies completed by undergraduate geoscience students working around the glaciers of Kongsfjord, Svalbard during the summer of 2014. It is intended as part of a larger Earth science unit that covers erosion, transport and deposition of sediment. Students connect authentic research to classroom investigations while learning how to interpret current data to understand geologic processes and Earth history.

Objectives

By the end of the lesson:

• Students can describe ways that glaciers change Earth’s surface.
• Students can explain how examination of sediment yields evidence about past geologic processes and Earth history.
• Students interpret data to describe possible geologic scenarios.

Lesson Preparation

Preparation includes making copies of student worksheets and handouts and creating colored, laminated copies of the core sample picture necessary for the student investigation. Additionally, preview of the video and power point is recommended along with setup of required audiovisual equipment.

This lesson presents one aspect of how Earth is transformed geologically and should be presented in the context of a larger unit that includes erosion by water and wind. It is assumed that students have completed prior units in an Earth science curriculum and have the requisite background knowledge necessary for mastery of the objectives.

Procedure

The components of the lesson are:

• A five minute video to generate interest, add authenticity and inform students about sample collection tools and methods.
• A teacher guided power point that explains how glacial processes shape Earth’s surface and how we know what we know.
• A reading handout that explains how sediment core samples are interpreted for student information and reference.
• A student investigation: students analyze a photograph of a glacier deposited sediment in groups and complete a student worksheet.
• A final writing assignment: students synthesize what they have learned by discussing their analysis and drawing conclusions about application to our current understanding of geologic processes and Earth history.
  The above order is suggested, however it can be modified to accommodate different age groups, time allotments, etc.

Extension

As an extension activity, students can make and use their own coring devices for extracting core samples from local lakes. A series of videos, demonstrating this process can be found at TMartScience:
http://www.youtube.com/channel/UCJ1-dZ8HrnDTwRGAGFaX0_w

Resources

Ridge, J.C. (January 6, 2015) The North American Glacial Varve Project.
Retrieved from http://eos.tufts.edu/varves

Assessment

Evidence of mastery of the objectives should be evident in students’ writing. Specifically, did they adequately:

• Outline glacier behavior (flows toward sea/erodes and deposits sediment)
• Determine the approximate number of years represented in the core sample
• Cite evidence for the above determination
• Describe seasonal variations and give reasonable causes.
• Describe annual variations and give reasonable causes.
• Describe trends (the older layers are thicker than the recent layers) and give reasonable causes.
• Connect the examination of sediment to geologic processes and Earth history.

Author / Credits

PolarTREC teacher, Peggy McNeal created this lesson based on her experience with High Arctic Change 2014. Peggy may be reached at peggy.mcneal [at] me.com.

Files Included

• Power Point: “Playing with Mud: Sediment Deposition by Tidewater Glaciers”
• Handout (one per student): Sediment Deposition by Tidewater Glaciers
• Color printed and laminated copies of Passumpsic Valley, East Barnet, VT, one per group
• Worksheet (one per student), Playing With Mud: Sediment Deposition by Tidewater Glaciers