Sea Level: Ice Volume Changes
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
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)
The pre-assessment is designed to assess students' knowledge regarding the stated lesson
objectives. The pre-assessment may be printed and distributed to the students. The teacher may
also print an answer sheet for scoring the pre-assessment or to compare student answers to
The post-test is designed to assess students' knowledge of the stated objectives after they have
completed the entire lesson. The post-assessment may be printed and distributed to the students.
The teacher may also print an answer sheet for scoring the post-assessment or to compare student
answers to correct answers.
Activities and Assignments
-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)
Handouts of the assessments and activity instructions may also be created before the
lesson to help students with the unit.
You can make an actual simulation as viewed in Exercise 1 of the presentation! To
make this model, you will need:
10 gallon aquarium, 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 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.
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 worksheets 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.
2/Sea Level: Ice Volume Changes
As students read through the presentation, they are encouraged to work through the
accompanying journal page. The page is an extension of the concepts in the lesson and allows
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.
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 worksheets 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.
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 students will then look at a simulation of ice melting from an iceberg 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.
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.
3/Sea Level: Ice Volume Changes
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.
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 or for printing
student work (graphs)
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.
4/Sea Level: Ice Volume Changes
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.
5/Sea Level: Ice Volume Changes
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
How the TEKS are Integrated into the
TEKS for Middle School Science
(6.2) (7.2) (8.2) The student uses scientific In Exercise 4, the student observes, collects,
inquiry during field and laboratory and measures data. The students will also
investigations. make conclusions based on what they learn
through the web pages and through hands on
(6.3) (7.3) (7.4) The student uses critical The student will make a model of an ice core
thinking and scientific problem solving to to represent the layering of Antarctic ice in
make informed decisions. the natural world.
(6.4)(7.4)(8.4) The student knows how to The student will use computers,
use a variety of tools and methods to conduct thermometers, and measurement devices to
science inquiry. analyze and record data in Exercise 4. They
may also use a microscope in examining the
characteristics of ice.
(6.7) The student knows that substances Through creating an ice core, students will
have physical and chemical properties. compare and differentiate between different
properties of ice and water and also discover
the effects of different temperatures.
(8.10) The student knows that complex Through the activities, student will describe
interactions occur between matter and how weather and climate systems impact
energy. ocean systems on Earth.
6/Sea Level: Ice Volume Changes
(8.12) The student knows that cycles exist in The student will relate the role of oceans to
Earth systems. climatic changes through learning about the
behavior and changes of the Earth's ice
Through the information in this lesson
(7.14) (8.14) The student knows that natural module, the student will gain an
events and human activity can alter Earth understanding of how climate changes and
systems. impacts the Earth. They will learn how
warmer climates can cause ice volume to
decrease and sea levels to rise. They will
discover how ice ages led to increased
amount of ice and lower sea levels. Students
will also focus on the concepts behind global
warming and its consequences.
TEKS for Middle School Technology How the TEKS are Integrated into the
(1) Foundations Students will demonstrate their ability to use
The student demonstrates knowledge and word processing and internet browsing
appropriate use of hardware components, software to access information throughout
software programs, and their connections. this unit. They will navigate through web
pages to complete activities concerning ice
(2) Foundations The mouse and keyboard will be used to
The student uses data input skills appropriate navigate through the appropriate web pages
to the task. and to access assignments.
(3) Foundations Students should follow appropriate
The student complies with the laws and classroom procedures for using the internet
examines the issues regarding the use of to gather information.
technology in society.
(4) Information Acquisition The student will use appropriate navigation
The student uses a variety of strategies to tools and search strategies to answer
acquire information from electronic questions within the exercises and complete
resources, with appropriate supervision. the activities of this unit.
7/Sea Level: Ice Volume Changes