GEOL 1301
Lab 09
Glaciers and Climate
This lab activity follows an online lab made available on the Science Education Resource Center at Carleton College website (http://serc.carleton.edu/eslabs/index.html). The lab has been developed with support from the National Science Foundation (NSF), the National Aeronautics and Space Administration (NASA), the National Oceanic and Atmospheric Administration (NOAA), the National Association of Geoscience Teachers (NAGT), and the Technical Education Research Center (TERC). Please upload your completed lab on Canvas.
Go to the following website:
http://serc.carleton.edu/eslabs/cryosphere/lab_overviews.html
On the left side of this website, you find a navigation panel to different parts of the lab. You will answer questions from Labs 1A, 1C, 2A, 2B, and 4A for this exercise, but feel free to explore all parts of the “Climate and Cryosphere” section.
Lab 1A: Getting to Know the Cryosphere
Study the image below, which you also find on the website of Lab 1 (http://serc.carleton.edu/eslabs/cryosphere/lab1.html), and read through the introduction to Lab 1 on that website.
Name all the parts of the cryosphere.
Describe the similarities or differences between the time scales at which the following components of the cryosphere change: snow, glaciers, ice sheets.
Cut out and tape together the cryosphere map that is found at the end of this lab document (you can also look for an image of what the completed “globe” should look like on the Lab 1A website, http://serc.carleton.edu/eslabs/cryosphere/1a.html). This globe shows the distributions of snow, ice, etc. averaged over several decades. Answer the following questions (some of which you also find on that same website):
What parts of the cryosphere are only found near the poles?
On December 26, 2000, there were reports of ten to twenty inches of snow across the Texas panhandle, including nearly twenty inches in the city of Amarillo. Why doesn’t the map show snow in Texas?
Where in North America do you find glaciers and ice caps?
To which latitude does sea ice extend in the northern hemisphere?
To which latitude does sea ice extend in the southern hemisphere?
Where do you find glaciers close to the equator? Why do you find them there?
Lab 1C: The Changing Cryosphere
Watch the satellite data-based NASA video “Tour of the Cryosphere” on the website for Lab 1C (http://serc.carleton.edu/eslabs/cryosphere/1c.html), then answer the following questions.
What is happening or has happened in the recent past to the ice shelves of Antarctica?
What is happening to sea ice coverage in the Arctic Ocean? Explain the “chain reaction” that is described in the video.
Where do most icebergs in the North Atlantic come from?
What is currently happening or has recently happened to the Jakobshavn Glacier in Greenland?
Lab 2A: Sea Ice and Ocean Currents
Go to the website for Lab 2A (http://serc.carleton.edu/eslabs/cryosphere/2a.html), then answer the following questions.
At what temperature does ocean water freeze?
What is a “brinicle” (watch also the video “Frozen Planet: Icy Finger of Death” on the website to answer this question)?
Go to the “Ocean Circulation” animation on the website, use the temperature slides, and describe what happens to the ocean water as sea ice forms.
Lab 2B: Sea Ice Thickness
Go to the website for Lab 2B (http://serc.carleton.edu/eslabs/cryosphere/2b.html), then answer the following questions.
How is sea ice thickness related to age?
Study the figure below (which is also shown on the website), which shows sea ice coverage and thickness in the Arctic Ocean as an average for February for the years 1985-2000 on the left and for February 2008 on the right. Describe the differences between the two images, and explain what they mean.
Lab 4A: Glacial Ages
Go to the website for Lab 4A (http://serc.carleton.edu/eslabs/cryosphere/4a.html), then answer the following questions.
From the image below (which you also find on the website), infer the typical time scale on which glacial periods occurred during the past 1 million years.
Timescale:
Read the section about Milankovitch Cycles. What are the three aspects of the Earth’s orbit that change over time, and at what time scales are they changing?
Cryosphere Map: