Granite Helps Scientists Piece Together Rodinia

If you’ve taught plate tectonics at the middle school level, you’re probably quite familiar with the supercontinent Pangaea. But did you know that Pangaea was not the only supercontinent in earth’s history – just the last to date? Millions of years before Pangaea, another supercontinent known as Rodinia united all of earth’s landmass in an unusual configuration. While we tend to think of Pangaea as the “starting point,” earth’s land and ocean basins have been continually shaped throughout geologic time through a supercontinent cycle.

While Pangaea certainly gets more press, Rodinia was the star of an article in the July 11, 2008 edition of Science. As summarized in a National Science Foundation News release, John Goodge’s team was collecting geologic specimens in the Transantarctic Mountains when they discovered a single granite boulder atop Nimrod Glacier.

Andrew Barth (L) and Devon Brecke (R), collecting glacial moraine samples in the Miller Range of the Transantarctic Mountains. Photo courtesy of John Goodge, University of Minnesota.

Subsequent chemical and isotopic tests indicated that the boulder was strikingly similar to a belt of igneous rock running through the southwestern United States. These similar chemical and isotopic signatures provided support for the SWEAT (southwest United States East Antarctica) hypothesis, which states that East Antarctica was connected to the southwestern United States approximately one billion years ago, as part of the global supercontinent Rodinia.

The supercontinent Rodinia as it began to break up approximately 750 million years ago.

At the heart of Rodinia was Laurentia, or the precursor to most of North America. Debate exists, however, on whether East Antarctica, Australia, Siberia, or South China fit with the western margin of Laurentia. This geologic discovery provides three lines of evidence in support of an East Antarctica – Laurentia connection.

Researchers theorize that about 600-800 million years ago, a portion of Rodinia broke away, gradually drifting southward to become eastern Antarctica and Australia. This movement just predates the Cambrian explosion, a rapid diversification of life and sudden appearance of complex organisms. Goodge explains that “there are ideas developing about these connections between the geo-tectonic world on the one hand and biology on the other.” It is possible that the shifting and colliding of continents, erosion, and influx of minerals and chemicals into the ocean may have provided nutrients to support a growing diversity of organisms.

Connecting to the National Science Education Standards

As with a discussion of Pangaea or plate tectonics in general, this article provides an opportunity to meet the Earth and Space Science standard’s various concepts. According to the National Science Education Standards, “The idea of systems provides a framework in which students can investigate the four major interacting components of the earth system – geosphere, hydrosphere, atmosphere, and the biosphere. In this holistic approach to studying the planet, physical, chemical, and biological processes act within and among the four components on a wide range of time scales to change continuously earth’s crust, oceans, atmosphere, and living organisms.” The holistic approach described in the NSES is reflected in this study’s use of geologic evidence to explain an important biological phenomenon.

How to Turn This News Event into an Inquiry-Based, Standards-Related Science Lesson

Rather than spark a new lesson, this current event provides an opportunity to revisit a familiar unit on plate tectonics, geologic time, and rocks and minerals. Most teachers include a discussion of Alfred Wegner and the evidence for his theory of plate tectonics, including similar fossilized plants and reptiles found in South America and Africa.

After students understand how Wegner used geologic and fossil evidence to reconstruct Pangaea, present the evidence from this most recent discovery. Ask them to explain how the same type of granite could be found in eastern Antarctica and the southwest United States. Once students conclude that the two continents must have been connected, re-examine a diagram of Pangaea, which shows an African-Antarctic connection, not a North America-Antarctic one. How, then, could these two places have similar rocks?

A reconstruction of the supercontinent Pangaea. Image courtesy of Kieff via Wikimedia.

Referring to geologic time may help at this point. Using a modified time scale, remind students that Pangaea existed approximately 200 million years ago, while earth is approximately 4.6 billion years old. What did earth’s surface look like before Pangaea? Lead students to the conclusion that other supercontinents, like Rodinia, existed well before Pangaea. Introduce the concept of the supercontinent cycle.

This type of discussion naturally progresses to the mechanics and processes driving the cycle: plate movement. The following resources from the Middle School Portal can help you teach about earth’s interior and plate tectonics. It may also be helpful to brush up on concepts related to geologic time, as these processes span millions of years.

Geologic Time: Eons, Eras, and Epochs

Plate Tectonics: Moving Middle School Science

Once students understand plate interactions (rifting, subduction, sea-floor spreading), take a global view. Using a world map, plot the locations of plate divergence and convergence. Challenge students to predict what the next supercontinent will look like. For example, current plate movement indicates that as the Atlantic Ocean basin grows, the Pacific Ocean basin is shrinking. In the future, western North America may be connected to Asia in the earth’s latest supercontinent. This story from NPR, Amasia: The Next Supercontinent?, tells the possible story.

Introducing Rodinia as part of a greater supercontinent cycle presents plate tectonics as a driving force in a long-term pattern of constructive and destructive forces. It provides another opportunity for students to consider the cyclic change: a fundamental principle in science.

We Want Your Feedback
We want and need your ideas, suggestions, and observations. What would you like to know more about? What questions have your students asked? We invite you to share with us and other readers by posting your comments. Please check back often for our newest posts or download the RSS feed for this blog. Let us know what you think and tell us how we can serve you better. We appreciate your feedback on all of our Middle School Portal 2 publications. You can also email us at msp@msteacher.org. This post was originally written by Jessica Fries-Gaither and published July 24, 2008 in the Connecting News to the National Science Education Standards blog. The post was updated 2/8/12 by Jessica Fries-Gaither.

Disaster in Japan

I’ve had lots of non-science friends ask me clarifying questions about what they have been hearing and seeing through the media – too bad for them I wasn’t an earth science teacher! I thought I would share some blog posts that have been helpful for me in trying to understand the what, why, and repercussions of the earthquake as well as a couple of posts from the New York Times that include lessons and activities.

You can also do a search in the Middle School Portal 2 Digital Library – you’ll get back resources that right on track for middle school science students.

Please share additional information and resources that have been helpful to you and your students in the comment section.

Resources

Japan Struggles to Control Quake-Damaged Nuke Plant – from Wired Science

Fukushima Nuclear Reactor Explained – video from CNN

Japan Quake May Have Shortened Earth Days, Moved Axis – from NASA

Recent Earthquake Teachable Moments: Animations from IRIS – includes video

The Japan Earthquake and Tsunami – from NSTA – includes lessons and activities

Teaching Ideas: The Earthquake and Tsunami in Japan – from New York Times Learning Network

20 Ways to Teach About the Disaster Across the Curriculum – from New York Times Learning Network

Building Quake-Resistant Structures in the Classroom –  from Middle School Portal 2 blog

Beyond Penguins Wins SPORE Award

Beyond Penguins and Polar Bears has been awarded the Science Prize for Online Resources in Education (SPORE) by Science Magazine. The magazine, which is published by the American Association for the Advancement of Science, developed the prize to spotlight the best online materials in science education.

Science editors and a panel of teachers and researchers in the fields select the prize winners. Kimberly Lightle and Jessica Fries-Gaither of the Beyond Penguins and Polar Bears staff were invited to write an essay about the project’s history and goals. The essay, Penguins and Polar Bears Integrates Science and Literacy, appears in the January 28 issue of Science.

Even though the magazine is directed at K-5 teachers, much of the content is applicable to the middle grades. Each of the 20 issues covers science concepts such as rocks and minerals, the water cycle, seasons, states and changes of matter, and plants, all in the context of the Arctic and Antarctica. Each issue highlights a literacy strategy, misconceptions, ideas on integrating technology, the research that is going on at the polar regions, and much more! Project staff have also written informational texts that have been differentiated in terms of reading level. The books are available in three versions – including an electronic version with an audio track. The Stories for Students link in the header of the site will take you to all versions of the books.

Teaching about Volcanic Hazards

You’ve probably heard that Redoubt, a volcano 100 miles southwest of Anchorage, Alaska, has been erupting intermittently since March 22. I used to live in Anchorage, so I’ve been keeping up with the volcano’s activity via the Alaska Volcano Observatory web site. I’m thankful that I’m not there to deal with the major hazard – ash.

redoubt.jpg
View to the east of the summit crater of Redoubt volcano, heavily covered with deposits from recent eruptions. The near ridge, right of the notch, is the upper reach of the Crescent Glacier on the southwest flank. March 31, 2009. Photo courtesy of Game McGimsey and the Alaska Volcano Observatory/U.S. Geological Survey.

Volcanic ash consists of tiny jagged pieces of rock and glass. These hard, abrasive particles are spread by wind and impact communities in a variety of ways – including damage to planes and cars, ventilation systems of buildings, water pollution, and possible respiratory problems.

 ash-sem.jpgash-sem.jpg
Scanning Electron Microscope image of ash particles erupted by Redoubt volcano on March 22, 2009. Image courtesy of Tom Kircher and the Alaska Volcano Observatory/University of Alaska Fairbanks Geophysical Institute.

In Alaska, Redoubt’s ashfall has led to flight cancellations, school closings, disruptions to the oil industry, and even delays in seafood shipments.

 ash-on-car.jpg
Volcanic ash fall out in Nikiski, AK from Redoubt volcano. Photo courtesy of Kristi Wallace and the Alaska Volcano Observatory/U.S. Geological Survey.

Other volcanic hazards include aerosols, lahars, pyroclastic flows, lava flows, and landslides. Some of the most well-known eruptions have caused a great deal of damage – think of the mudflows after the 1991 eruption of Mount Pinatubo or the explosion and ash cloud of Mount St. Helens in 1980. Scientists are trying to better understand the inner workings of volcanoes to predict eruptions and minimize damage. During an eruption such as Redoubt’s current activity, mathematical modeling of atmospheric currents helps predict which areas will be most affected by ashfall.

While volcanoes are almost always part of a broader study of plate tectonics, we don’t always take the time to focus on the impacts of eruptions on humans. The following resources take this approach to studying volcanoes and thus align with the Science in Personal and Social Perspectives content standard of the National Science Education Standards.

Volcanoes – Local Hazard, Global Issue
http://missiongeography.org/58mod1.htm
This module allows middle school students to explore two ways that volcanoes affect Earth: by directly threatening people and environments adjacent to them and by ejecting aerosols into the atmosphere. Through three investigations, students explore issues of volcano hazards at different scales, from their local environment to the global effect of volcanic aerosols on climate and aircraft safety.

Mount Pinatubo: The Aftermath of a Volcanic Eruption
http://www.teachersdomain.org/resource/ess05.sci.ess.earthsys.lahar/
This video (3:30) shows the ash fall and mud flows triggered by the eruption of Mount Pinatubo in 1991. Questions for discussion lead students to consider the effects of volcanic eruptions on humans and how communities near volcanoes can protect themselves in the future.

Volcano Hazards Program
http://volcanoes.usgs.gov/
The USGS web site provides information about the 169 active volcanoes in the United States, teaching resources, information about volcanic ash, and volcano webcams.

Volcanoes and Climate Change
http://eob.gsfc.nasa.gov/Features/Volcano/
This article from NASA explains how volcanic eruptions impact global climate.

Seismic Signals
http://www.teachersdomain.org/resource/ess05.sci.ess.earthsys.seismic/
This interactive activity from NOVA Online illustrates some of the clues seismologists are using to better understand activity within a volcano and predict eruptions.


We Want Your Feedback
We want and need your ideas, suggestions, and observations. What would you like to know more about? What questions have your students asked? We invite you to share with us and other readers by posting your comments. Please check back often for our newest posts or download the RSS feed for this blog. Let us know what you think and tell us how we can serve you better. We appreciate your feedback on all of our Middle School Portal 2 publications. You can also email us at msp@msteacher.org. Post updated 12/07/2011.

Hot Spots (Even in Cold Places)

Did you know that there’s an active volcano in Antarctica?

Mt. Erebus, the world’s southernmost active volcano, is located on Ross Island, just off the coast of Antarctica in the Ross Sea. Part of the Ring of Fire, Mt. Erebus is located along the boundary of the Scotia and Antarctic tectonic plates.

Students may be surprised to learn that an active volcano can be found in such a cold location. Yet the heat of a volcano and its lava has nothing to do with weather and climate and everything to do with Earth’s internal structure and the theory of plate tectonics. The connection between plate movement and volcanic activity is part of the typical middle school curriculum and included in the Earth and Space Science content standard of the National Science Education Standards for grades 5-8.

Too often, students’ experience with volcanoes comes in the form of baking soda/vinegar models, which can actually lead to the formation of misconceptions. Instead, use the following resources to help your students more accurately model and visualize volcanic activity.

Volcanoes
http://www.teachersdomain.org/resource/ess05.sci.ess.earthsys.lp_volcanoes/NSDL Annotation
In this multi-day lesson, students investigate the processes that build volcanoes, the factors that influence different eruption types, and the threats volcanoes pose to their surrounding environments. After exploring these characteristics, students use what they have learned to identify physical features and eruption types in some real-life documented volcanic episodes. The lesson includes the use of many multimedia resources from the Teacher’s Domain collection.

Mt. Erebus Volcano Observatory
http://erebus.nmt.edu/
The MEVO web site provides background knowledge, video, photos, and other resources about the world’s southernmost active volcano.

Volcanology
http://www.spacegrant.hawaii.edu/class_acts/VolcanologyDoc.html
Five lessons from the Hawai’i Space Grant Consortium provide opportunities for students to learn about magma’s movement inside volcanoes, the stratigraphy of lava flows, structures formed by lava, how particle size affects the angle of a volcano’s slope, and how to measure a liquid’s viscosity. Each lesson includes separate student and teacher pages.

Exploring the Environment: Volcanoes
http://www.cotf.edu/ete/modules/volcanoes/volcano.htmlNSDL Annotation
A problem-based learning module in which students use online information to make decisions regarding four well known volcanoes. Designed for students in grades 7-12, but could be used with younger students needing additional challenge.

Plate Tectonics: Moving Middle School Science
http://msteacher.org/epubs/science/science1/science.aspxNSDL Annotation
The study of volcanoes at the middle school level is incomplete without a connection to the theory of plate tectonics. Discover background information, animations, activities, and standards alignment.

We Need Your Help

We want and need your ideas, suggestions, and observations. What would you like to know more about? What questions have your students asked? We invite you to share with us and other readers by posting your comments. Please check back often for our newest posts or download the RSS feed for this blog. You can also request email notification when new content is posted (see right navigation bar).

Let us know what you think and tell us how we can serve you better. We want your feedback on all of the NSDL Middle School Portal science publications. Email us at msp@msteacher.org.