Ice Core Investigations: Exploring Climate Change in Ice Core Samples
Krim, Jessica, Brody, Michael, The Science Teacher
What can glaciers tell us about volcanoes and atmospheric conditions? How does this information relate to our understanding of climate change? Ice Core Investigations is an original and innovative activity that explores these types of questions. It brings together popular science issues such as research, climate change, ice core drilling, and air pollution to create a meaningful science learning experience for students.
Teaching science and climate change
Typically, we may teach our students about climate by having them memorize the types and locations of different climates, and their influences on Earth's ecosystems. However, science teachers can easily modify this and other traditional approaches to be an interesting inquiry-based activity that allows students to examine a simulated record of climate change. Through the study of ice core samples, Ice Core Investigations leads students to a greater understanding of the natural systems involved in climate change, the history of Earth's climate, and the human influences on climate today. Students investigate the relationship between airborne particles in a glacial ice core, the thickness of layers within the core sample, and pH values. In the analysis of these ice cores, students make predictions and draw conclusions similar to scientists' findings, increasing their familiarity and experience with current climate change research.
While we usually see the study of climate and ecosystems in Earth and physical science classes at the 8th and 9th-grade levels, the content of the Ice Core Investigations lesson is interdisciplinary and applicable to several areas of science at the 10th- and 11-grade levels as well. The approach used in this lab could easily be used in a chemistry class to illustrate concepts of acids, bases, and suspensions or in a biology class to make connections between water quality and conditions for life.
[FIGURE 1 OMITTED]
Glaciers hold many clues about climate and atmospheric conditions throughout Earth's history. Within glaciers, there are sequential layers of ice deposition that contain characteristics of the atmosphere at the time they formed. Within an ice core, it is possible to infer differences in temperature, precipitation, atmospheric composition, volcanic activity, and wind patterns using a typical coring strategy (Palais et al. 1988; Zielinski et al. 1994; Fiedel, Southon, and Brown 1995; Riebeek 2005).
Scientists drill into ice sheets or glaciers and then label and analyze the ice core for data, which can include oxygen isotopes, layer thickness, the gases in air bubbles, methane levels, chemical composition of dust, and dates of ash layers. From these measurements we can infer atmospheric conditions and global climate at the time the sample formed. In the Ice Core Investigations activity, students analyze ice core samples (created by the teacher) and focus on three variables: the thickness of the ice, the presence of airborne particles, and the pH value of each section of the sample.
Connecting to the "big picture"
Throughout Earth's history, there have been extended periods of volcanic activity, which have greatly affected Earth's climate. Volcanoes emit ash and gases that affect atmospheric conditions, which, in turn, affect climate. In most cases, greatly increased volcanic emissions cause colder global temperatures and acidic precipitation. These geological events are recorded in the layers of ice found in glaciers and correlate directly with climate conditions inferred from tree-ring growth data from the same time period.
We are well aware of the critical role that air pollution, especially carbon-dioxide emissions, plays in global climate change. From bacterial microbes to plants and animals including humans, air pollution affects all Earth systems, and industrial pollution can clearly be seen within the ice core record. …