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Going to Extremes New Zealand American Submarine Ring of Fire 2007 Going to Extremes FOCUS AUDIO/VISUAL MATERIALS Archaea (Optional) Equipment for viewing online or downloaded video of vent communities GRADE LEVEL 9-12 (Biology) TEACHING TIME One or two 45-minute class periods, plus time for FOCUS QUESTION student research What are Archaea, and what is their potential significance in hydrothermal communities of the SEATING ARRANGEMENT Kermadec Arc? Classroom style if students are working individu- ally, or groups of two to four students LEARNING OBJECTIVES Students will be able to define “lipid biomarkers,” MAXIMUM NUMBER OF STUDENTS and explain what the presence of certain bio- 30 markers signifies. KEY WORDS Students will be able to describe Archaea, and Kermadec Arc explain why these organisms are often consid- Hydrothermal field ered to be unusual. Archaea Prokaryote Students will be able to compare and contrast Eukaryote Archaea with bacteria and eukaryotes. Methanogen Methanotroph Students will be able to define methanogen and Chemoautotroph methanotroph, and explain the relevance of these terms to Archaea. BACKGROUND INFORMATION The Submarine Ring of Fire is an arc of active vol- Students will be able to discuss the potential sig- canoes that partially encircles the Pacific Ocean nificance of Archaea in hydrothermal communi- Basin, including the Kermadec and Mariana ties of the Kermadec Arc. Islands in the western Pacific, the Aleutian Islands between the Pacific and Bering Sea, the Cascade MATERIALS Mountains in western North America, and numer- Copies of “Going to Extremes Worksheet,” one ous volcanoes on the western coasts of Central copy for each student or student group America and South America. These volcanoes result from the motion of large pieces of the 1 New Zealand American Submarine Ring of Fire 2007 – Grades 9-12 (Biology) Focus: Archaea oceanexplorer.noaa.gov Earth’s crust known as tectonic plates. This volca- gence of the Cocos and Caribbean Plates pro- nic activity releases immense quantities of heat, duces active volcanoes on the western coast of minerals, gases and other substances, and often Central America, and convergence of the North produces “hydrothermal systems” or seafloor American and Juan de Fuca Plates causes the vol- hot springs. These processes influence the entire canoes of the Cascades in the Pacific Northwest. ocean, and support unique biological communi- ties. Many species in these communities are new On the western side of the Pacific Ocean, the to science, and have a high potential for develop- Pacific Plate converges against the Philippine ing important new natural products for industrial Plate and Australian Plate. Subduction of the and medical applications. In addition, fluids Pacific Plate creates the Mariana Trench (which produced by volcanic activity often have high includes the Challenger Deep, the deepest known concentrations of metals that quickly precipitate in area of the Earth’s ocean) and the Kermadec cold ocean waters, and may be directly linked to Trench. As the sinking plate moves deeper into the formation of ores and concentrated deposits the mantle, new magma is formed as described of gold and other precious and exotic metals. above, and erupts along the convergent bound- ary to form volcanoes. The Mariana and The junction of two tectonic plates is called a Kermadec Islands are the result of this volcanic “plate boundary,” and three major types of plate activity, which frequently causes earthquakes as boundary are produced by tectonic plate move- well. The movement of the Pacific Ocean tectonic ments. If two tectonic plates collide more or less plate has been likened to a huge conveyor belt head-on they form a convergent plate boundary. on which new crust is formed at the oceanic Usually, one of the converging plates will move spreading ridges, and older crust is recycled to beneath the other, which is known as subduction. the lower mantle at the convergent plate bound- The junction of two tectonic plates that are mov- aries of the western Pacific. For more informa- ing apart is called a divergent plate boundary. tion on plate tectonics, visit the NOAA Learning Magma rises from deep within the Earth and Objects Web site (http://www.learningdemo.com/noaa/). erupts to form new crust along submarine moun- Click on the links to Lessons 1, 2 and 4 for inter- tain ranges called oceanic spreading ridges. active multimedia presentations and Learning The third type of plate boundary occurs where Activities on Plate Tectonics, Mid-Ocean Ridges, tectonic plates slide horizontally past each other, and Subduction Zones. and is known as a transform plate boundary. As the plates rub against each other, huge stresses Since they were discovered in 1977, hydrother- are set up that can cause portions of the rock to mal vent communities associated with divergent break, resulting in earthquakes. plate boundaries have been extensively studied. In contrast, much less is known about hydrother- The volcanoes of the Submarine Ring of Fire result mal systems near convergent plate boundaries from the motion of several major tectonic plates. like those of the Mariana and Kermadec Arcs. The Pacific Ocean Basin lies on top of the Pacific Beginning in 2002, Ocean Exploration expedi- Plate. To the east, along the East Pacific Rise, new tions have undertaken systematic mapping and crust is formed at the oceanic spreading center study of hydrothermal systems in previously-unex- between the Pacific Plate and the western side plored areas of the Submarine Ring of Fire. Visit of the Nazca Plate. Farther to the east, the east- • http://oceanexplorer.noaa.gov/explorations/02fire/logs/ ern side of the Nazca Plate is being subducted magicmountain/; beneath the South American Plate, giving rise to • http://www.oceanexplorer.noaa.gov/explorations/03fire/; active volcanoes in the Andes. Similarly, conver- • http://www.oceanexplorer.noaa.gov/explorations/04fire/; 2 New Zealand American Submarine Ring of Fire 2007 – Grades 9-12 (Biology) oceanexplorer.noaa.gov Focus: Archaea • http://www.oceanexplorer.noaa.gov/explorations/05fire/; dominated by Archaea. These microbes obtain and energy from methane in the cold spring fluid, and • http://oceanexplorer.noaa.gov/explorations/06fire/welcome. may be key primary producers in biological com- html munities associated with these volcanoes. Other for more information about the many discover- new and unique microbes are expected to be ies, as well as still and video imagery, from found in association with extreme vent fluids as these expeditions. The New Zealand American other sites are identified and explored along the Submarine Ring of Fire 2007 Expedition is Kermadec Arc. focused on detailed exploration of hydrothermal systems at Brothers Volcano in the Kermadec Arc, In this lesson, students will investigate some of the an area where tectonic plates are converging strangest and most fascinating of these microbes: more rapidly than any other subduction zone in the Archaea, whose specialty is living in some of the world. the most extreme environments on Earth. When seawater penetrates the permeable ocean LEARNING PROCEDURE crust in the vicinity of volcanoes, increased heat 1. To prepare for this lesson, review the introduc- and pressure cause a variety of gases, metals tory essays for the New Zealand American and other materials to dissolve into the water Submarine Ring of Fire 2007 Expedition at from the surrounding rock. This process causes http://oceanexplorer.noaa.gov/explorations/07fire/welcome. many metals to be concentrated by a thousand to html. a million times their concentration in normal sea- water. When the fluid is vented into cold ocean You may also want to review background water, some dissolved substances precipitate out information on lipid biomarkers and Archaea of solution, forming metal deposits, “chimneys,” at http://exobiology.arc.nasa.gov/ssx/biomarkerlab/index.html and “black smokers.” Dissolved gases may react and http://www.ucmp.berkeley.edu/archaea/archaea.html. to form other materials. At NW Rota Volcano, for example, dissolved sulfur dioxide forms sulfuric 2. Briefly review: acid and elemental sulfur. At NW Eifuku Volcano, (a) The concepts of plate tectonics, being sure 1,600 meters below the sea surface, the 2004 that students understand the processes that Ring of Fire Expedition found buoyant droplets take place at convergent and divergent of liquid carbon dioxide, probably formed from boundaries, and why these boundaries are degassing of a carbon-rich magma. often the site of volcanic activity; and (b) Hydrothermal vents, cold seeps, and the Hydrothermal fluids also provide an energy Submarine Ring of Fire, emphasizing distinc- source for a variety of chemosynthetic microbes tions between the characteristics and origin that in turn are the basis for unique food webs of vented fluids. Point out that each of these associated with hydrothermal vents. Many of habitats is associated with distinct living these microbes have specific adaptations to communities, and that they are all based on extreme conditions; scientists found evidence for chemoautotrophic organisms that are able to microbes living in hot spring fluids on NW Rota thrive in conditions that would be lethal for with a pH of 2.0 or less. At another extreme, cold most species and are also able to use sub- springs on mud volcanoes on the Mariana Arc stances in vent fluids as energy sources for (also formed by subduction of the Pacific Plate the synthesis of essential compounds needed beneath the Philippine Plate) have been found to by living organisms. have a pH of 12.5, and microbial populations 3 New Zealand American Submarine Ring of Fire 2007 – Grades 9-12 (Biology) Focus: Archaea oceanexplorer.noaa.gov 3. This lesson may be undertaken as an individual merits classifying Archaea as an entirely sep- student activity or by small groups of 2 - 4 stu- arate group. Life on Earth is now classified dents. Because the assignment requires signifi- into three “domains:” Bacteria, Eukaryota, cant student research and potentially novel con- and Archaea.
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