Author Archives: Sarah Pryputniewicz

Geological models to help students explore the Earth

Geoscience poses many questions. Why are there continents and oceans? How do mountains form? Why do volcanoes form in some areas and not others? What causes earthquakes to be more frequent in some areas than others? Why are oil, diamond, gold, and other deposits clustered in particular areas rather than being spread evenly across the world?

Teaching geoscience poses significant challenges. Experiments with Earth’s geology are impossible, and many of the natural processes that shape Earth, such as sedimentation, folding, and faulting, take place out of sight, over unimaginably long time periods. We think that technology has the potential help to transform how geoscience is taught and understood.

From the people who brought you High-Adventure Science comes the GEODE (Geological Models for Explorations of Dynamic Earth) project. Funded by the National Science Foundation, the new project aims to design dynamic, interactive, computer-based models and curricula to help students understand how Earth’s surface and subsurface features are shaped. As in the High-Adventure Science modules, GEODE modules will incorporate real-world data and computational models, with a focus on making scientific arguments based on evidence.

The GEODE  project, a partnership between the Concord Consortium and The Pennsylvania State University, held a kickoff brainstorming session Monday, September 27. Principal Investigator Amy Pallant and Co-PI Hee-Sun Lee, both of the Concord Consortium, and Co-PI Scott McDonald of Penn State organized a meeting to begin developing a plate tectonics model to accompany the recently developed Seismic Explorer.

In Seismic Explorer, students can see patterns of earthquake data, including magnitude, depth, location, and frequency.

In Seismic Explorer, students can see patterns of earthquake data, including magnitude, depth, location, and frequency.

seismicexplorer-cross-section

Students can make a cross-section to see a three-dimensional view of the earthquakes in an area.

Professional geologists, geoscience educators, and software developers reviewed the currently available models and simulations of plate motion, earthquake waves, sedimentation, folding, and faulting, and discussed ways to make these concepts accessible to middle and high school students.

We look forward to sharing more models and activities as they are developed over the next few years!

High-Adventure Science Partnership with National Geographic Education

We are excited to announce that the Concord Consortium’s High-Adventure Science modules are now available on the National Geographic Education website, thanks to a National Science Foundation-funded partnership with National Geographic Education. High-Adventure Science modules have been used by thousands of students so far, and we welcome the opportunity to share our modules with a wider audience of middle and high school teachers and students. All modules will continue to be available on the High-Adventure Science website.

High-Adventure Science: Bringing contemporary science into the classroom

Each week-long High-Adventure Science module is built around an important unanswered question in Earth or environmental science; topics include fresh water availability, climate change, the future of our energy sources, air quality, land management, and the search for life in the universe.

Throughout each module, students learn about the framing question, experiment with interactive computer models, analyze real world data, and attempt to answer the same questions as research scientists. We don’t expect that students will be able to answer the framing questions at the end of the module (after all, scientists are still working to answer them!); rather, we want to engage students in the process of doing science, building arguments around evidence and data and realizing that not knowing the answers (uncertainty) drives scientific progress.

To that end, each module (and associated pre- and post-tests) contains several scientific argumentation item sets. The argumentation item set, with multiple-choice and open-ended questions, prompts students to consider the strengths and weaknesses of the provided data (graphs, models, tables, or text). Our research has shown that, after using High-Adventure Science modules, students improve both their understanding of the science content and their scientific argumentation skills. Register for a free account on the High-Adventure Science portal for access to pre- and post-tests.

Expanded teacher resources through National Geographic Education

Partnering with National Geographic Education has allowed us to provide more support for teachers. On the National Geographic Education website, you’ll find in-depth teaching tips, background information, vocabulary definitions, and links to the standards (NSES, Common Core, ISTE, and NGSS) to which our curricula are aligned. Additionally, each module is linked to related resources in the National Geographic catalog, greatly expanding the resources available to both teachers and students.

Teachers have been excited about the models, real world data, and the argumentation prompts that get students to focus on the evidence when making a scientific claim. (You can hear directly from one of the High-Adventure Science field test teachers at NSTA!)

Come see us at NSTA in Nashville, TN, this week! Stop by the National Geographic booth or come to a presentation about using High-Adventure Science modules in your classroom:

  • “High-Adventure Science: Free Simulations Exploring Earth’s Systems and Sustainability” on Thursday, March 31, from 12:30-1:00 PM in Music City Center, 106A
  • “Integrating Literacy Standards in Science” on Sunday, April 3, from 8:00-9:00 AM in Music City Center, 209A

 

Scoring explanation-certainty items in High-Adventure Science

One of the questions unique to the High-Adventure Science project is what we call the explanation-certainty item set. These item sets consist of four separate questions:

  1. Claim
  2. Explanation
  3. Rating of certainty
  4. Certainty rationale

In the first High-Adventure Science project, we developed these items as a reliable way to assess student argumentation and developed rubrics to score the items, which I’ll explain below. (You can also look at Exploring the Unknown, our first publication in The Science Teacher. Check out our Publications tab for a list of (and link to) all of the publications generated from High-Adventure Science.)

Scoring the Claim item:

The scoring for this portion of the explanation-certainty item set is fairly straight-forward. Where there is a correct answer, the correct answer gets a point, and the incorrect answer gets zero points. Where there is no correct answer (because the problem is so nuanced and/or there is not enough information to make a definitively correct answer), we score into categories. For instance, in this question from the water module, there is no definitively correct answer:

A farmer drills a well to irrigate some nearby fields.
Could the well supply a consistent supply of water for irrigation?

No-one knows if the answer is yes or no until the wells run dry!

Scoring the Explanation item:

Explain your answer.

The scoring for this portion of the explanation-certainty item set follows the generic rubric seen below. Basically, we’re assessing whether (and to what extent) the student is able to make scientific claims.

What’s a scientific claim?

Scientific claims are backed by evidence. The more links a student is able to make between the evidence and the argument, the higher on the scale s/he scores.

Screen shot 2013-09-19 at 12.13.35 PM

It’s helpful to look at a couple of examples to really understand how this works.

Here are some “student” responses to the explanation portion following the claim question about irrigation of fields.  (Note that I made these up to be illustrative; they are not actually from students.)

  • Student A: I don’t know.
  • Student B: The well could supply irrigation easily for many years.
  • Student C: The farmer might be drilling into a confined aquifer so the well wouldn’t last forever.
  • Student D: After the water is used, it will sink back into the ground and be ready to pump up again.
  • Student E: If the well is pumping from a confined aquifer, it won’t be recharged by precipitation. That means that the well won’t last forever.
  • Student F: If the farmer had a limited amount of crops to irrigate, and the well was drilled into an unconfined aquifer so that it could be recharged by the rainfall, then the well might last forever. But if the well went into a confined aquifer, it would eventually run out.
  • Student G: If the farmer drilled into an unconfined aquifer, the well might last forever. But that depends on how much water is being pumped out vs. how much can be recharged by precipitation. If the sediments above the aquifer are very permeable, then the aquifer will recharge quickly, but if they are not super-permeable, the aquifer will take some time to recharge, so it’s possible to pump the well dry, if only temporarily. If the farmer drills into a confined aquifer, the water might last a really long time (fi the aquifer is huge), but since it can’t be recharged because the sediments above it are impermeable, it would eventually run out of water.

How would you score these responses?

The first thing to think about is what the “best answer” looks like. Some of the sample answers are pretty good. But how do you distinguish between good, pretty good, and excellent?

The answer lies in the number of ideas in the answer and whether those ideas are linked. For instance, the main ideas to consider in the “best answer” are:

  • wells pump from aquifers
  • aquifers can be confined or unconfined
  • unconfined aquifers can be recharged by precipitation
  • confined aquifers are not recharged by precipitation
  • recharge happens more quickly when the sediments overlying the aquifer are more permeable (and more slowly when sediments are less permeable)
  • the amount of water in the aquifer is a limiting constraint (you can’t pump more than exists!)

Making links between these ideas is the key to a good scientific argument. The ideas for the “best answer” vary between explanation items, but the scoring idea is the same across all High-Adventure Science explanation items.

  • Score 0: no links, no scientific claim present
  • Score 1: no links (if a claim is present)
  • Score 2: any one idea
  • Score 3: one link between ideas
  • Score 4: two or more links between ideas

So, scoring the student responses:

  • Student A: This one is easy. The student did not make any claim or provide any evidence. This response scores a 0.
  • Student B: There’s a claim, but does it contain any key ideas? No, so this scores a 1.
  • Student C: This student brings up the idea of a confined aquifer. That’s one idea, so it’s a score of 2.
  • Student D: This student recognizes that water flows in a cycle and that water sprayed on the crops will percolate down through the soil. That’s only one of the main ideas, so this response also gets a score of 2.
  • Student E: This student makes the link between recharge and unconfined aquifers. This response scores a 3.
  • Student F: This student brings in three links: unconfined aquifers are recharged; confined aquifers are not recharged; and rainfall provides recharge. This response scores a 4.
  • Student G: This student brings in all of the ideas. There is a discussion of why unconfined aquifers are recharged by precipitation while confined aquifers are not. There is a discussion about how the permeability of sediments affects the rate of recharge. There is a discussion about the size of the aquifer. This response also scores a 4.

Scoring the Certainty Rating item:

How certain are you about your claim based on your explanation?

We use this as an indication of how strongly a student is confident in his/her argument. There are no right or wrong answers here.

Scoring the Certainty Rationale item:

Explain what influenced your certainty rating.

Like the Explanation item, the scoring for this item follows a rubric. Unlike the rubric for the Explanation item, however, this follows a rubric that’s very easy to generalize across all topic areas.

Screen shot 2013-09-19 at 12.19.38 PM

Students use many different reasons for their uncertainty, but they can be broadly categorized as personal, scientific within the investigation, and scientific beyond the investigation.

Personal reasons include:

  • My teacher told me.
  • I learned it from a science show.
  • I read it in a magazine.
  • I’m not really good at this topic.  (or conversely, I’m really good at this topic.)
  • I haven’t learned this yet. (or conversely, we learned this last year.)

Scientific within the investigation reasons include evidence from within the question or specific knowledge directly related to the question.

Scientific beyond the investigation reasons include:

  • questioning the data or evidence presented in the question
  • recognizing limitations in scientific knowledge about the topic
  • recognizing the inherent uncertainty in the phenomenon (in this case, the uncertainty of knowing the type of aquifer from which the well is pulling its water)

So there you have it – a nutshell view of how we score the certainty-explanation items in High-Adventure Science.

If you want to use parts of this rubric to score your students’ responses for your own grading, that’s great! Feel free to ask questions as they come up. The scoring is not always easy!  🙂

Using Dynamic Models to Discover the Past (and the Future?)

What was Earth like 2.8 billion years ago?  The first life was emerging on the planet.  The Sun was weaker than it is today, but geologic evidence shows that the climate was as warm (or warmer) than it is today.  Was Earth colder because of the weak Sun, or warmer, as geologic evidence suggests?  How did this affect how life arose?

A new 3-D model of early Earth suggests that the planet underwent significant changes–from very warm to very cold.  Past models were one-dimensional–holding constant the amount of cloud cover or sea ice–to make the calculations easier.  But with more advanced computing, researchers at the University of Colorado Boulder were able to make better models of the planet’s climate.

“The inclusion of dynamic sea ice makes it harder to keep the early Earth warm in our 3-D model,” Eric Wolf, doctoral student at CU-Boulder’s atmospheric and oceanic sciences department, said. “Stable, global mean temperatures below 55 degrees Fahrenheit are not possible, as the system will slowly succumb to expanding sea ice and cooling temperatures. As sea ice expands, the planet surface becomes highly reflective and less solar energy is absorbed, temperatures cool, and sea ice continues to expand.”

The scientists’ model shows that Earth was periodically covered by glaciers, but the geologic evidence suggests that it was much warmer than that.  The calculations show that an atmosphere that contained 6% carbon dioxide would have kept the temperature high enough for life to thrive, but the soil samples show that the carbon dioxide concentration was not that high. So what’s the warming mechanism?  Eric Wolf and Brain Toon are still searching for it.

Since the 3-D model takes so much computing time (up to three months for a single calculation), we’ll be waiting a while for the answer.

“The ultimate point of this study is to determine what Earth was like around the time that life arose and during the first half of the planet’s history,” said Toon. “It would have been shrouded by a reddish haze that would have been difficult to see through, and the ocean probably was a greenish color caused by dissolved iron in the oceans. It wasn’t a blue planet by any means.” By the end of the Archean Eon some 2.5 billion year ago, oxygen levels rose quickly, creating an explosion of new life on the planet, he said.

And along the way, better models of Earth’s climate will come out of this study, enhancing scientists’ ability to predict what Earth’s future might look like, and scientists will learn more about the conditions of early Earth, which could help in assessing the habitability potential of other planets.

Explore the interactions of greenhouse gases and ice sheets in the High-Adventure Science climate investigation, and explore the search for extraterrestrial life in the High-Adventure Science space investigation.

http://www.sciencedaily.com/releases/2011/12/111205140521.htm

The Great Antarctic Glaciation

About 33 million years ago, the Earth abruptly went from being warm and wet to having Antarctic ice cover.  Only 23 million years after the Paleocene-Eocene Thermal Maximum, a time of some of the warmest temperatures on Earth, ice covered the surface.  What happened?

According to a recent study by scientists at Yale and Purdue universities, the carbon dioxide level dropped. Carbon dioxide is a greenhouse gas that is contributing to the increased global temperatures on Earth today.

The scientists pinpointed the threshold for low levels of carbon dioxide below which an ice sheet forms at the South Pole. Matthew Huber, a professor of earth and atmospheric sciences at Purdue, said roughly a 40 percent decrease in carbon dioxide occurred prior to and during the rapid formation of a mile-thick ice sheet over the Antarctic approximately 34 million years ago.

“The evidence falls in line with what we would expect if carbon dioxide is the main dial that governs global climate; if we crank it up or down there are dramatic changes,” Huber said. “We went from a warm world without ice to a cooler world with an ice sheet overnight, in geologic terms, because of fluctuations in carbon dioxide levels.”

Having an ice-covered South Pole appears to be the tipping point for cooling the rest of the planet.  The team found that the threshold level of carbon dioxide necessary for ice formation is about 600 parts per million.  For reference, today’s carbon dioxide level is approximately 390 parts per million.  This is why ice sheets still remain on Earth today.

With carbon dioxide levels forecast to rise to 550-1,000 parts per million in the next 100 years, when will the ice sheets completely melt away?  Because the melting of an ice sheet is different than starting an ice sheet, and because the process is not linear, scientists can’t say for sure.  But it’s clear that once the carbon dioxide levels rise high enough, the Earth will have reached a tipping point in the warming direction and the ice sheets will melt away.

Huber next plans to investigate the impact of an ice sheet on climate.

“It seems that the polar ice sheet shaped our modern climate, but we don’t have much hard data on the specifics of how,” he said. “It is important to know by how much it cools the planet and how much warmer the planet would get without an ice sheet.”

So how warm will Earth be in the future?  What’s the cooling impact of the ice?  Will greenhouse gases continue to rise?  Will increased cloud cover compensate for the lack of ice?

Explore how greenhouse gases and ice affect Earth’s temperature and learn more about feedback and tipping points in the High-Adventure Science climate investigation.

http://www.sciencedaily.com/releases/2011/12/111201174225.htm

When in Drought…

New groundwater and soil moisture drought indicator maps produced by NASA are available on the National Drought Mitigation Center’s website. They currently show unusually low groundwater storage levels in Texas. The maps use an 11-division scale, with blues showing wetter-than-normal conditions and a yellow-to-red spectrum showing drier-than-normal conditions. (Credit: NASA/National Drought Mitigation Center)

GRACE groundwater map of continental U.S.

The map (above) shows the change in stored groundwater in the contiguous United States.  Texas, which experienced record heat and wildfires this summer, is experiencing a very severe drought.  The change in stored water should not be a surprise given the weather conditions of the past year.  (By contrast, New England has a surplus of water from a very wet summer and the remnants of Hurricane Irene.)

Drought maps offer farmers, ranchers, water resource managers and even individual homeowners a tool to monitor the health of critical groundwater resources. “People rely on groundwater for irrigation, for domestic water supply, and for industrial uses, but there’s little information available on regional to national scales on groundwater storage variability and how that has responded to a drought,” Matt Rodell, a hydrologist at NASA’s Goddard Space Flight Center, said. “Over a long-term dry period there will be an effect on groundwater storage and groundwater levels. It’s going to drop quite a bit, people’s wells could dry out, and it takes time to recover.”

The question is: how long will it take to replenish the water that has been removed from the aquifers in Texas? Matt Rodell estimates, “Texas groundwater will take months or longer to recharge.  Even if we have a major rainfall event, most of the water runs off. It takes a longer period of sustained greater-than-average precipitation to recharge aquifers significantly.”

Water is a resource that everyone needs.  In dry environments, such as southwestern Texas, water is especially precious.  Water is used for the usual personal purposes, for agricultural purposes, and in natural gas wells.  For example, accessing the natural gas in the Eagle Ford shale deposit, which runs from the Mexican border towards Houston and Austin, requires millions of gallons of water to fracture the shale and release the stored hydrocarbons.

The prolonged Texas drought is putting more pressure on local officials about how best to use the limited amount of groundwater.  What is the best way to use the water supply?  Who gets first dibs?  How much should different businesses pay for water?  These are highly-important questions that can only be answered with a full understanding of how groundwater works.

You can explore how groundwater flows and propose solutions to water-supply issues in the High-Adventure Science water investigation.

http://www.nasa.gov/topics/earth/features/tx-drought.html

Drought spurring fracking concerns

Oil’s Growing Thirst for Water

Texas

More planets!

A team of astronomers led by scientists at the California Institute of Technology have found 18 planets orbiting stars more massive than our Sun.  Finding planets is becoming more and more routine with the Kepler telescope, but these planetary discoveries help to answer questions about planetary formation–and raise other questions about planetary orbits.

The scientists focused on stars more than 1.5 times more massive than our Sun.  To look for planets, they used the “wobble” method, which looks for shifts in the apparent wavelengths coming from the star.  The 18 planets that they found are all larger than Jupiter.

According to John Johnson, assistant professor of astronomy at Caltech, these discoveries support a theory of planet formation. There are two competing explanations for how planets form: a) tiny particles clump together to make a planet and b) large amounts of gas and dust spontaneously collapse into big dense clumps that become planets.

The discovery of these planets supports the first explanation.

If this is the true sequence of events, the characteristics of the resulting planetary system — such as the number and size of the planets, or their orbital shapes — will depend on the mass of the star. For instance, a more massive star would mean a bigger disk, which in turn would mean more material to produce a greater number of giant planets.

So far, as the number of discovered planets has grown, astronomers are finding that stellar mass does seem to be important in determining the prevalence of giant planets. The newly discovered planets further support this pattern — and are therefore consistent with the first theory, the one stating that planets are born from seed particles.

The larger the star, the larger the planets that orbit it.

“It’s nice to see all these converging lines of evidence pointing toward one class of formation mechanisms,” Johnson says.

But there’s another mystery that’s come out of this discovery.  The orbits of these 18 newly-discovered large planets are mainly circular.  Planets around other Sun-like stars have circular and elliptical orbits.  Is there something about the larger stars that make it more likely  that planets will have a circular orbit?  Or is it just a phenomenon noticed because of the small sample size? Johnson says he’s now trying to find an explanation.

Stay tuned–not only may we find a planet that could harbor life, we could also learn something about the origin of our own solar system!

Learn more about finding planets and the search for extraterrestrial life in the High-Adventure Science investigation, Is there life in space?

http://www.sciencedaily.com/releases/2011/12/111202155801.htm

What caused the Paleocene-Eocene Thermal Maximum?

What caused the Paleocene-Eocene Thermal Maximum (PETM)?

About 56 million years ago, Earth’s temperature was a lot warmer than it is today–as much as 21°F higher than today (see the graph).  Earth’s temperature is rising today, likely because of human emissions of greenhouse gases.  But 56 million years ago, there were no human emissions; there were no humans.  What caused the big increase in Earth’s temperature?  And could it happen again today?

Researchers at Rice University suggest that the temperature increase could well be due to releases of stored methane from the oceans.

Methane is a powerful greenhouse gas and a natural product of bacterial decomposition.  In the oceans, methane sinks into the sediments and freezes into a slushy gas hydrate, stabilized in a narrow band under the seafloor.

According to calculations done by the Rice University scientists, the warmer oceans resulted in more methane hydrate being stored.  At warmer temperatures, bacteria decompose organic materials faster, resulting in more methane in a shorter period of time.  They estimate that, just before the PETM, there was as much methane hydrate stored as there is today, in a smaller band than exists today.

If this band is disturbed, as by a meteor impact or earthquake, the methane can be rapidly released into the atmosphere.  More greenhouse gases in the atmosphere result in increased warming.  But there’s no evidence of there having been an impact.  So what happened to release the methane 56 million years ago?

Nobody really knows, but the significance is clear.

“I’ve always thought of (the hydrate layer) as being like a capacitor in a circuit. It charges slowly and can release fast — and warming is the trigger. It’s possible that’s happening right now,” said Gerald Dickens, a Rice professor of Earth science and an author of the study.

That makes it important to understand what occurred in the PETM, he said. “The amount of carbon released then is on the magnitude of what humans will add to the cycle by the end of, say, 2500. Compared to the geological timescale, that’s almost instant.”

“We run the risk of reproducing that big carbon-discharge event, but faster, by burning fossil fuel, and it may be severe if hydrate dissociation is triggered again,” Guangsheng Gu, lead author of the study, said, adding that methane hydrate also offers the potential to become a valuable source of clean energy, as burning methane emits much less carbon dioxide than other fossil fuels.

Learn more about the feedback loops involved in climate change in the High-Adventure Science climate investigation.

http://www.sciencedaily.com/releases/2011/11/111109111542.htm

When More Is More

In science, less isn’t more; more is more.

That basic premise is supported by a recent report from Lawrence Livermore National Laboratory: Separating signal and noise in climate warming.  Earth’s overall temperature is affected by natural processes, such as La Niña and El Niño, as well as by human factors.

From 1999 to 2008, Earth’s temperature was fairly steady, coming after the steady rise in temperature that occurred from the late 1980s.  What happened in that 10 year period?  Probably noise from natural phenomena, conclude scientists at LLNL.

“Looking at a single, noisy 10-year period is cherry picking, and does not provide reliable information about the presence or absence of human effects on climate,” said Benjamin Santer, a climate scientist and lead author on an article in the Nov. 17 online edition of the Journal of Geophysical Research (Atmospheres).

The solution?  Look at longer time periods to see past the natural noisy fluctuations in Earth’s temperature data.  After looking at all of the data, scientists concluded that temperature records must be at least 17 years long to see the human-caused warming amidst the natural fluctuations.  More data leads to more accurate conclusions.

Explore the hows of climate change in the High-Adventure Science climate investigation.

https://www.llnl.gov/news/newsreleases/2011/Nov/NR-11-11-03.html

Absolute Certainty Is Not Scientific

That’s the title of an editorial by Daniel Botkin, president of the Center for the Study of the Environment and professor emeritus at the University of California, in today’s Wall Street Journal.

With the ongoing polarization of science in today’s political environment, it’s more important than ever to remember that science is filled with uncertainty.  Everything that scientists know about how the world works has been discovered by observation and experimentation.  None of us were around at the very beginning, so we can never be absolutely certain about how the world works, though we can be very certain that we understand how it works.

You can’t prove anything to be true in science.  This seems unintuitive to many people, including many of my former students, who used to insist that they had proven their point because the data supported their hypotheses.  But since we will never be absolutely certain about how the world works, we can never prove that any particular hypothesis or theory is absolutely true.  That’s why good scientists design experiments to disprove their hypotheses.  While you can’t prove anything to be true, you can prove things to be false.

So good scientists are forever questioning their assumptions, looking for evidence that their hypotheses and theories are wrong, open to the idea that they may have misinterpreted the data.  It’s vitally important for science teachers to remind their students to have this kind of healthy skepticism; scientific progress cannot easily proceed if people entrench themselves into opposing camps without regard for the data.

This is something that the High-Adventure Science investigations aim to do–immerse students in the data about climate change, finding extraterrestrial life, and freshwater resources–without making all-or-nothing judgements about the current state of the science.

“If you think that science is certain–well that’s just an error on your part.” ~Richard Feynman

http://online.wsj.com/article/SB10001424052970204630904577058111041127168.html?mod=WSJ_Opinion_LEADTop#articleTabs%3Darticle