Ice Volume -- Teacher's Notes and Standards

Lesson

Teacher's Notes

Standards (TEKS)

(Click here to access a printable version of this Lesson Plan!)

Objectives
The student will be able to:

Explain the relationship between ice volume and the Earth's sea level.

Describe how differences in ice volume and composition relate to changes in the Earth's climate.

Lesson Description
Through this lesson, students should gain a basic understanding of how the Earth's climate has changed over time and impacted the ice volume of the planet. The changes in ice volume have been recorded in layers of ice found at the poles and studied through ice core samples. Changes in ice volume have played a role in the rise and fall of sea level over many thousands of years. As the climate warmed, ice melted and seas rose. As the climate cooled, ice froze and sea levels dropped. Students will discover that the past, present, and future trends of ice volume and sea level based on the changes in Earth's climate. They will learn about ice ages and current global warming trends. The main exercise involves building a model of an ice core to learn about the characteristics of ice. The model will illustrate how scientists learn about the past from ice core samples. Students will complete activity worksheets and keep journals to share their knowledge and new ideas throughout the unit.

SUGGESTED TIME FOR ENTIRE UNIT: 1 week (5 days)

Pre-Assessment
The pre-assessment is designed to assess students' knowledge regarding the stated lesson objectives.

To access a printable version of the pre-assessment to view or copy for students, click here.

To view or print a copy of the answers to pre-assessment questions, click here.

Post-Assessment
The post-test is designed to assess students' knowledge of the stated objectives after they have completed the entire lesson.

To access a printable version of the post-assessment to view or copy for students, click here.

To view or print a copy of the answers to post-assessment questions, click here.

Activities and Assignments
Materials
plastic bottles, one per student or per group (can be 20 ounce empty soda bottles, cleaned and dry, with the labels peeled off)
ice shavings (option: ice may be crushed in a blender into small pieces)
permanent markers (to label bottle with the student's name and record ice level and date)
access to a freezer (to keep the students' ice cores frozen)

Optional:
Handouts of the assessments, activity pages, journal pages, and instructions may be printed and copied before the lesson to help students through the unit.
Journal Page
Activity Pages for Exercise 1, Exercise 2, Exercise 3 (Answer Key for activities)
Observation Journal for Exercise 4

You may also make an actual simulation as viewed in Exercise 1 of the presentation! To make this model, you will need:

10 gallon aquarium (see picture), dimensions 20"X10"X12" (can be purchased at Walmart)
Medium-sized mixing bowl (2 quart sized, to make the iceberg)
Measuring tape or stick to track water level changes
Food coloring or Blue Kool-Aid to color the water
Make the Continental Shelf (see picture) from scraps of wood:
-8"X10" piece of 3/8" thick plywood
-1.75"X8" piece of 3/8" plywood
-2 pieces of 7"X2" (1" thick) plywood
-3.5"X2" piece of 1" thick plywood
-7 wood screws (1")

For Exercise 4, you may want to have food coloring on hand to color the ice shavings so that students can more easily observe changes in their "ice cores".

Also, you may want to make ice shavings using different sources of water. By freezing distilled, lake, pond, or other types of water, students may use them to create diverse layers in their ice core for comparison.

Procedures
As an option, the teacher may guide the students through the information by projecting the web lesson onto a screen. This is effective in classrooms where there may be fewer computers. Another option is to have students work on the unit themselves or in small groups, with the teacher monitoring as they navigate through the information on the website.

The teacher may want to print the journal pages and activity pages for the class before the lesson begins. That way, students can answer the questions as they read through each of the sections on the computer and make their observations. The teacher can use the Activity Pages Answer Key to help evaluate student progress.

1. Through the Introduction, students will learn that the focus of this unit is long-term global sea level changes caused by ice volume changes. The introduction relates the previous unit on Tides (short-term sea level change) to this unit on ice volume (long-term sea level changes).

2. The Presentation begins by defining the different types of glaciers (valley and continental). Background is given on the types of ice and the locations of ice on the Earth. The Presentation also describes the relationship between the oceans and the amount of ice on the Earth, relating sea level to the amount of water released or contained by the Earth's ice sheets. The last portion of the Presentation describes the past ice age, the current state, and the future of the Earth's ice sheets. It concludes with a discussion on the effects that global warming may have on the Earth's sea level and ice volume.

As students read through the presentation, they are encouraged to work on the journal pages. These pages are an extension of the concepts in the lesson and allow students to use what they have learned to answer some creative thinking questions. The first part of the journal focuses on ice ages and encourages students to think about how their life would be difference if the Earth were currently in an ice age. The second part focuses on global warming and asks students to consider what would happen if the ice shelves melted. Since they are meant to encourage creative thinking and application of the concepts from the presentation, evaluation of student work on this activity is left to the discretion of the teacher. (View journal pages.)

3. The Activity involves 4 Exercises, each of these exercises has a series of questions and the final exercise is a hands-on experiment, where the student will create their own ice core. The activity pages and journal pages for these exercises include focus questions and may be printed so that the students can record their answers as they read through the information and complete the tasks. (View Activity Worksheet Answer Key)

Exercise 1 (Activity Page 1)
In this exercise, students view a simulation of ice melting. In the first animation, they will see an iceberg floating in water. As the ice melts, the sea level rises very little (if at all). This is because the water has already been displaced by the iceberg, since it was already sitting in the water.
The students will then look at a simulation of ice melting from an ice berg that is raised out of the water. Because the water has NOT been displaced by the ice, as the ice melts, the water level rises a great deal as all of the water from the iceberg drips into the standing water.
Students are asked to make observations about these two simulations. The teacher may use the directions above to create a live simulation of the icebergs melting. The water tanks are to simulate the world's oceans. A description of how the models depict the ice volume' s effects on sea level are provided in the activity.
Questions are given at the conclusion of exercise 1, asking students to think about what caused the ice to melt as well as to report what changes occurred during the simulations.
Teachers are encouraged to create an actual ice simulation for their classroom. (Directions for the simulation are given above.) Students may gain a better understanding by viewing the simulations in person in addition to seeing the animation on the web.

Exercise 2 (Activity Page 2)
This exercise refers to an animation of the Antarctic Ice Sheet melting since the last ice age. The students are to visit a website by CNN and read an article about how the volume of the ice in Antarctica has decreased in the past twenty thousand years. Based on their knowledge and conclusions from this animation and article, they are asked a series of questions. Finally, they are invited to visit a page with further information about the shrinking of ice sheets since the last ice age.

Exercise 3

(Activity Page 3)
In this exercise, students learn about the progression from land-locked ice to sea bound ice. They will view some examples of iceberg formations off the Antarctic coast. This exercise relates to the first exercise's simulations, pointing out that sea level changes is not based so much on the ice that is already in the ocean, but on the melting of the land-based ice sheets and formations. There is a startling graphic that illustrates how the world would be covered with water if the West Antarctic Ice Sheets melted. Other webpages are provided that discusses information on the East Antarctic Ice Sheets. Once again questions are provided that relate the web sites visited in the exercise.

Exercise 4 (Journal/Observation Page)
Students will explore the characteristics of ice and how ice cores can unlock information about climatic changes. They will make their own ice core using clear plastic bottles. Students will add ice shavings in layers, freeze, thaw, add more ice, then refreeze their own ice cores over a few days. Students will record the level of ice on their bottles and record observations concerning their ice cores in journal entries. Students will also make predictions and write down their conclusions in these journals. The teacher should print out journal pages each day for students to complete as they make their regular observations and changes to their ice cores. By the end of the unit, students will have a journal about the changes that took place to the ice in their ice cores. The teacher may have students share their findings with the class throughout the activity. This project will give students a better understanding of how layers of ice in core samples are studied to learn about past changes in the Earth's climate. Extension activities are provided to enhance the lesson.

At the conclusion of all exercises, the teacher should conduct a wrap-up discussion. Students may want to share what they have learned through a free writing activity or the teacher may lead a discussion in preparation for the post-test.

Tools and Resources
Hardware used in this lesson:
Computer: With keyboard, mouse, and operating system such as Windows 95
Printer- (optional): For printing out instructions and assessments for the class
Projector- (optional): Such as a Proxima projector, that is capable of projecting computer images onto a screen so that the whole class may view the lesson along with the teacher
Software used in this lesson:
Microsoft Internet Explorer or Netscape Navigator: To view the lesson, access the links, data, and pictures
Microsoft WORD: To view printable documents and print them.
Web sites used in the lesson:
CNN NASA Animation: This site is used in Exercise 2 and includes a description of how the ice volume of Antarctica has changed over time. It also explains a NASA graphic that illustrates this reduction in ice volume.
North American Ice Sheets: This site describes the behavior and changes of the North American Ice Sheet during and since the last Ice Age.
Antarctic Ice Shelves and Icebergs & Calving of Iceberg A-38: These sites describe the formation of icebergs as they break off from main ice shelves.
Water World: This is a page created by NOVA (a PBS television program) that describes what would happen to the world's sea levels if the ice shelves melted. There are some interesting graphics that show how cities such as New York and Washington DC would be underwater if too much of the ice shelves disappeared into the sea!
How Fast Can a Glacier Change: This page includes estimates on time responses of land-based glaciers such as the East Antarctic ice sheet. It describes melting patterns for valley based glaciers and ice sheets.
Estimated Sea Level Rise Potential: From the USGS, this page provides estimates on the impacts of melting ice formations on sea level.
Oxygen Isotopes: This page describes how oxygen isotope curves are used to date layers of ice in a core sample. This page is very complex and might be difficult to understand for some students.

Extensions and Modifications (Optional)
As an extension to Exercise 4, the teacher may have students use microscopes to view samples from different parts of their ice core, once the bottle is full. Students may document their findings in their journals. Also, the students may compare their ice samples to others in the class. Allow students access to different types of ice (from different sources of water) to vary their ice core samples. Have students compare and contrast these differences in their journals.

The teacher may also use food coloring to color the ice so that students can clearly see the different layers and/or changes in their core sample.

If there is not enough freezer space for every student or there are not enough bottles, small groups of students may work on the cores together. Groups of 3 or 4 or pairs of students may work on developing and observing one ice core sample together. If a group of students is to create an ice core, the teacher may consider using 1 or 2 liter bottles instead of the smaller bottles so that students can better see the changes to their ice.

This lesson may be modified in its presentation. The teacher may want to do the lesson from the computer, projecting the information on a screen in front of the class and asking questions along the way. Presenting the lesson in this way may assist students who are not comfortable with navigating around the Internet or in classrooms where there are few computers or Internet connections.

Standards Targeted