Ice Cores ores Exploring the History of Climate Change

Good Morning! Get out your vocabulary. I will be coming around to check it during class. Read the ½ sheet about ice cores and complete the questions on the backside. (middle of table) Ice Core Video

Ice Core Analysis What type of atmospheric data might be useful to show evidence of climate change in an ice core? What data can be measured from an ice core?

Ice Core Analysis How might scientists relate a given layer of ice with a given time period? How would they know the age of each layer?

Looking at the Ice Core Looking at this ice core, which layer of the ice core is the oldest? Youngest? How do you know? Now observe the ice core for your lab today. Which layer is the oldest? Youngest? Why?

Why are ice cores so important? Hold records of how and why our climate has changed. The ice of glaciers starts as snow, and that snow forms around particles in the atmosphere, and that snow accumulates on glaciers. This annual accumulation of snow allows us to count back annual layers hundreds to thousands to tens of thousands of years and they allow us to observe changes in climate that happen very quickly (geologically speaking)

What kinds of things can ice cores tell us? Small bubbles in ice hold trapped atmospheric gases from hundreds of thousands of years ago. When scientists analyze the composition of those trapped gases they are measuring the concentrations of gases in Earth's atmosphere when each layer was formed, including the concentration of carbon dioxide, a greenhouse gases. The water also holds oxygen and hydrogen isotopes which will vary depending on temperature when the layer was created. Layers containing volcanic ash make it possible to determine when eruptions took place.

What is a pH scale? The pH scale measures how acidic or basic a substance is. The pH scale ranges from 0 to 14 (0=most acidic, 14= most basic) A pH of 7 is neutral. Example: pure water A pH less than 7 is acidic Examples: lemon juice, vinegar, stomach acids A pH greater than 7 is basic Examples: laundry detergents, ammonia

What do the pH levels in ice cores tell us? CO2 (carbon dioxide), when in water, becomes carbonic acid and drops the pH level (making the water more acidic). Measuring pH levels in ice cores indicates the relative levels of CO2 in the atmosphere at that period of time.

Ice Core Lab-Follow Up Discussion Which layers represent wet or dry years? How do you know? Were some layers more acidic than others? How does this relate to climate change? Did the particles in each layer vary? What might be the sources of these particles in the atmosphere?

CLEAN UP! All liquid ice and particles need to be poured into the bucket or pan near the sink in the back of the room. All small containers need to be rinsed out and returned to your table. Plastic knives need to be returned to the teacher lab table.

How can ice core samples tell us the history of climate change? EXIT SLIP On your note card answer the following question. Turn in when complete. How can ice core samples tell us the history of climate change?

Additional videos: http://earththeoperatorsmanual.com/segmen t/5 https://www.youtube.com/watch?v=fuT8App wak8