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Windows to the Deep Exploration

The Big Burp: A Bad in the

FOCUS SEATING ARRANGEMENT Global warming and the Paleocene extinction Groups of 4-6 students

GRADE LEVEL MAXIMUM NUMBER OF STUDENTS 5-6 (Earth Science) 30

FOCUS QUESTION KEY WORDS How could global warming have been responsible Cold seeps for the Paleocene extinction 55 million Methane hydrate ice ago? Clathrate Methanogenic Archaeobacteria LEARNING OBJECTIVES Greenhouse gases Students will be able to describe the overall events Greenhouse effect that occurred during the Paleocene extinction event. Paleocene extinction event explosion Students will be able to describe the processes that are believed to result in global warming. BACKGROUND INFORMATION The Blake Ridge is a large sediment deposit located Students will be able to infer how a global warm- approximately 400 km east of Charleston, South ing event could have contributed to the Paleocene Carolina on the continental slope and rise of the extinction event. United States. The crest of the ridge extends in a direction that is roughly perpendicular to the conti- MATERIALS nental rise for more than 500 km to the southwest  Drawing materials (for students constructing geo- from water depths of 2,000 to 4,800 m. Over the logical 30 years, the Blake Ridge has been extensively studied because of the large deposits of methane AUDIO/VISUAL MATERIALS hydrate found in the area. Methane hydrate is a  None (illustrations from http://www.uky.edu/KGS/ type of clathrate, a chemical substance in which the education/activities.html# and/or http://www.palaeos.com molecules of one material (water, in this case) form may be used for the student-constructed geologi- an open lattice that encloses molecules of another cal timeline, but are optional) material (methane) without actually forming chemi- cal bonds between the two materials (visit http:// TEACHING TIME 198.99.247.24/scng/hydrate/about-hydrates/about_hydrates.htm One or two 45- class periods, plus time for to see a model of a methane hydrate clathrate). group research 1 Windows to the Deep – Grades 5-6 (Earth Science) Windows to the Deep – Grades 5-6 (Earth Science) Focus: Global warming and the Paleocene extinction oceanexplorer.noaa.gov oceanexplorer.noaa.gov Focus: Global warming and the Paleocene extinction

Methane is produced in many environments by The release of large quantities of methane gas can a group of Archaea known as the methanogenic have other consequences as well. Methane is one Archaeobacteria. These Archaeobacteria obtain of a group of the so-called “greenhouse gases.” energy by anaerobic metabolism through which In the atmosphere, these gases allow solar radia- they break down the organic material contained in tion to pass through but absorb heat radiation once-living plants and animals. When this process that is radiated back from the Earth’s surface, thus takes place in deep ocean sediments, methane warming the atmosphere. Many scientists have sug- molecules are surrounded by water molecules, and gested that increased carbon dioxide in the atmo- conditions of low temperature and high pressure sphere produced by burning fossil fuels is causing allow stable ice-like methane hydrates to form. a “greenhouse effect” that is gradually warming Scientists are interested in methane hydrates for the atmosphere and the Earth’s surface. A sudden several reasons. A major interest is the possibility release of methane from deep-sea sediments could of methane hydrates as an energy source. The U.S. have a similar effect, since methane has more than Geological Survey has estimated that on a global 30 the heat-trapping ability of carbon dioxide. scale, methane hydrates may contain roughly twice the carbon contained in all reserves of coal, oil, In 1995, Australian paleoceanographer Gerald and conventional natural gas combined. In addi- Dickens suggested that a sudden release of tion to their potential importance as an energy methane from submarine sediments during the source, scientists have found that methane hydrates Paleocene (at the end of the Tertiary Period, are associated with unusual and possibly unique about 55 million years ago) caused a greenhouse biological communities. In September, 2001, the effect that raised the temperatures in the deep Ocean Exploration Deep East expedition explored ocean by about 6° C. The result was the extinc- the crest of the Blake Ridge at a depth of 2,154 m, tion of many deep-sea organisms known as the and found methane hydrate-associated communities Paleocene extinction event. More recently, other containing previously-unknown species that may be scientists have suggested that similar events could sources of beneficial pharmaceutical materials. have contributed to mass extinctions during the period (183 million years ago), as well While such potential benefits are exciting, methane as to the sudden appearance of many new animal hydrates may also cause big problems. Although phyla during the Cambrian period (the “Cambrian methane hydrates remain stable in deep-sea sedi- explosion, about 520 million years ago). ments for long periods of time, as the sediments become deeper and deeper they are heated by the A key objective of the 2003 Windows to the Deep Earth’s core. Eventually, temperature within the sed- Ocean Exploration expedition is to investigate the iments rises to a point at which the clathrates are possible release of methane from methane hydrates no longer stable and free methane gas is released to the atmosphere and the potential impact of these (at a water depth of 2 km, this point is reached at releases on global warming. This activity focuses a sediment depth of about 500 m). The pressurized on methane hydrates, global warming, and the gas remains trapped beneath hundreds of meters Paleocene extinction event. of sediments that are cemented together by still- frozen methane hydrates. If the overlying sediments LEARNING PROCEDURE are disrupted by an earthquake or underwater 1. Lead an introductory discussion of the 2003 landslide, the pressurized methane can escape Windows to the Deep Ocean Exploration suddenly, producing a violent underwater explo- expedition. At this point tell students only that sion that may result in disastrous tsunamis (“tidal the expedition is investigating areas of the waves”). Blake Ridge that contain substances called

2 3 Windows to the Deep – Grades 5-6 (Earth Science) Windows to the Deep – Grades 5-6 (Earth Science) Focus: Global warming and the Paleocene extinction oceanexplorer.noaa.gov oceanexplorer.noaa.gov Focus: Global warming and the Paleocene extinction

methane hydrates. Tell students that scientists ticularly in the case of the Paleocene extinc- often find that events and processes that at tion event). Have students discuss whether first seem completely unrelated turn out to be these events are always bad. You may want closely connected, and that this is particularly to point out that some scientists believe that a true for processes that operate on a global global warming event led to the emergence of scale or over long periods of time. Say that many new groups of animals, possibly includ- they are going to investigate the possible con- ing our own distant ancestors. Students should nections between methane hydrates, global recognize that “bad” depends upon your warming, and a mass extinction event that perspective: if your species becomes extinct, took place about 55 million years ago. you probably think that’s bad; but if a warm- ing event makes it possible for your species to 2. Assign one or more groups to research the fol- exist, then you’ll probably think that’s good. lowing topics: The point is, global warming in our time may • methane hydrates (What are they? Where have major negative consequences for human are they found? Why are they important?) populations (and probably for many other • global warming (What is it? What do scien- species); but other species may benefit from tists think may cause it?) such an event. • the Paleocene extinction event (What hap- pened? What are possible causes?) THE BRIDGE CONNECTION • a summary of geological (This group www.vims.edu/bridge/ – Enter “greenhouse” in the should create a timeline showing when the “Search” box, then click “Search” to display entries Paleocene occurred, and some of the other on the BRIDGE website for global warming and the major events in geological history; http:// greenhouse effect. www.uky.edu/KGS/education/geologictimescale.pdf and http://www.uky.edu/KGS/education/activities.html#time THE “ME” CONNECTION have lots of good information and resourc- Have students write a short essay from two view- es for this activity … so much, in fact, that points, one describing how a global extinction you may want to make this a separate event is “good,” the other describing how the same activity involving the entire class). event is “bad.”

You may want to direct students to some or CONNECTIONS TO OTHER SUBJECTS all of the information sources listed under English/Language Arts, Biology, Chemistry “Resources,” or you may want to have stu- dents discover these (or other) information EVALUATION sources on their own. One or both of the following products provide opportunity for assessment: 3. Have each group results of their • Results and presentation of the research com- research. After presentations are completed, ponent of the activity; lead a discussion of how these topics may • Individual or group written reports interpret- be related. Be sure students understand what ing the combined research results of all groups methane hydrates are, why they are of practi- prior to group discussion. cal interest and importance to us, how they may periodically release large quantities of EXTENSIONS methane gas to the atmosphere, and what the Log on to http://oceanexplorer.noaa.gov consequences of such releases might be (par- to keep up to date with the latest Blake Ridge

2 3 Windows to the Deep – Grades 5-6 (Earth Science) Windows to the Deep – Grades 5-6 (Earth Science) Focus: Global warming and the Paleocene extinction oceanexplorer.noaa.gov oceanexplorer.noaa.gov Focus: Global warming and the Paleocene extinction

Expedition discoveries, and to find out what Paull, C.K., B. Hecker, C. Commeau, R.P. Feeman- researchers are learning about cold-seep communi- Lynde, C. Nuemann, W.P. Corso, G. ties. Golubic, J. Hook, E. Sikes, and J. Curray. 1984. Biological communities at Florida Log onto http://oceanography.geol.ucsb.edu/Ocean_Materials/ Escarpment resemble hydrothermal vent Mini_Studies/Greenhouse_gases/Greenhouse_gases.html for more communities. Science 226:965-967 – early information and activities related to the greenhouse report on cold seep communities. effect. Kirschvink, J. L. and T. D. Raub. 2003. A methane RESOURCES fuse for the Cambrian explosion: carbon http://oceanexplorer.noaa.gov – Follow the Blake Ridge cycles and true polar wander. Comptes Expedition daily as documentaries and dis- Rendus Geoscience 335:65-78. Journal arti- coveries are posted each day for your class- cle on the possible role of methane release in room use. rapid diversification of animal groups. Also available on-line at www.gps.caltech.edu/users/ http://198.99.247.24/scng/hydrate/about-hydrates/about_ jkirschvink/ pdfs/KirschvinkRaubComptesRendus.pdf hydrates.htm – Website for the National Methane Hydrate R&D Program Simpson, S. 2000. Methane fever. Scientific American (Feb. 2000) pp 24-27. Article http://www.resa.net/nasa/ocean_methane.htm – Links to about role of methane release in the other sites with information about methane Paleocene extinction event. hydrates and associated communities NATIONAL SCIENCE EDUCATION STANDARDS http://www.uky.edu/KGS/education/geologictimescale.pdf and http:// Content Standard A: Science As Inquiry www.uky.edu/KGS/education/activities.html#time – Great • Abilities necessary to do scientific inquiry resources on geological time and major • Understanding about scientific inquiry events in Earth’s history Content Standard B: Physical Science http://www.rps.psu.edu/deep/ – Notes from another expedi- • Properties and changes of properties in matter tions exploring deep-sea communities • Motions and forces • Transfer of energy http://ridge2000.bio.psu.edu/nonsciencelinks.htm – Links to other deep ocean exploration web sites Content Standard C: Life Science • Populations and ecosystems http://www-ocean.tamu.edu/education/oceanworld/resources/ – Links to other ocean-related web sites Content Standard D: Earth and Space Science • Earth’s history http://www.geol.ucsb.edu/faculty/valentine/Valentine%202002.pdf – Review of methane-based chemosynthetic Content Standard E: Science and Technology processes • Abilities of technological design • Understandings about science and technology http://www.palaeos.com/ – Lots of information about life Content Standard F: Science in Personal and Social on earth, , , etc., Perspectives with many illustrations • Natural hazards • Risks and benefits

4 5 Windows to the Deep – Grades 5-6 (Earth Science) Windows to the Deep – Grades 5-6 (Earth Science) Focus: Global warming and the Paleocene extinction oceanexplorer.noaa.gov oceanexplorer.noaa.gov Focus: Global warming and the Paleocene extinction

• Science and technology in society

FOR MORE INFORMATION Paula Keener-Chavis, National Education Coordinator/Marine Biologist NOAA Office of Exploration 2234 South Hobson Avenue Charleston, SC 29405-2413 843.740.1338 843.740.1329 (fax) [email protected]

ACKNOWLEDGEMENTS This lesson plan was produced by Mel Goodwin, PhD, The Harmony Project, Charleston, SC for the National Oceanic and Atmospheric Administration. If reproducing this lesson, please cite NOAA as the source, and provide the following URL: http://oceanexplorer.noaa.gov

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