New Zealand American Submarine Ring of Fire 2007 My Friend, The Volcano (adapted from the 2004 Submarine Ring of Fire Expedition) FOCUS MAXIMUM NUMBER OF STUDENTS Ecological impacts of volcanism in the Mariana 30 and Kermadec Islands KEY WORDS GRADE LEVEL Ring of Fire 5-6 (Life Science/Earth Science) Asthenosphere Lithosphere FOCUS QUESTION Magma What are the ecological impacts of volcanic erup- Fault tions on tropical island arcs? Transform boundary Convergent boundary LEARNING OBJECTIVES Divergent boundary Students will be able to describe at least three Subduction beneficial impacts of volcanic activity on marine Tectonic plate ecosystems. BACKGROUND INFORMATION Students will be able to explain the overall tec- The Submarine Ring of Fire is an arc of active vol- tonic processes that cause volcanic activity along canoes that partially encircles the Pacific Ocean the Mariana Arc and Kermadec Arc. Basin, including the Kermadec and Mariana Islands in the western Pacific, the Aleutian Islands MATERIALS between the Pacific and Bering Sea, the Cascade Copies of “Marianas eruption killed Anatahan’s Mountains in western North America, and numer- corals,” one copy per student or student group ous volcanoes on the western coasts of Central (from http://www.cdnn.info/eco/e030920/e030920.html) America and South America. These volcanoes result from the motion of large pieces of the AUDIO/VISUAL MATERIALS Earth’s crust known as tectonic plates. None Tectonic plates are portions of the Earth’s outer TEACHING TIME crust (the lithosphere) about 5 km thick, as Two or three 45-minute class periods, plus time well as the upper 60 - 75 km of the underlying for student research mantle. The plates move on a hot flowing mantle layer called the asthenosphere, which is several SEATING ARRANGEMENT hundred kilometers thick. Heat within the asthe- Classroom style, if students are working individu- nosphere creates convection currents (similar to ally, or groups of two to four students the currents that can be seen if food coloring is 1 New Zealand American Submarine Ring of Fire 2007 – 5-6 (Life Science/Earth Science) Focus: Ecological impacts of volcanism in the Mariana and Kermadec Islands oceanexplorer.noaa.gov added to a heated container of water). These these breaks occur are called faults. A well-known convection currents cause the tectonic plates to example of a transform plate boundary is the San move several centimeters per year relative to Andreas Fault in California. See animations of each other. different types of plate boundaries at: http://www. seed.slb.com/en/scictr/watch/living_planet/plate_boundaries/ The junction of two tectonic plates is called a plate_move.htm. “plate boundary.” Three major types of plate boundaries are produced by tectonic plate move- The volcanoes of the Submarine Ring of Fire result ments. If two tectonic plates collide more or less from the motion of several major tectonic plates. head-on they form a convergent plate boundary. The Pacific Ocean Basin lies on top of the Pacific Usually, one of the converging plates will move Plate. To the east, along the East Pacific Rise, new beneath the other, which is known as subduction. crust is formed at the oceanic spreading center Deep trenches are often formed where tectonic between the Pacific Plate and the western side plates are being subducted, and earthquakes are of the Nazca Plate. Farther to the east, the east- common. As the sinking plate moves deeper into ern side of the Nazca Plate is being subducted the mantle, fluids are released from the rock caus- beneath the South American Plate, giving rise to ing the overlying mantle to partially melt. The new active volcanoes in the Andes. Similarly, conver- magma (molten rock) rises and may erupt violent- gence of the Cocos and Caribbean Plates pro- ly to form volcanoes, often forming arcs of islands duces active volcanoes on the western coast of along the convergent boundary. These island arcs Central America, and convergence of the North are always landward of the neighboring trenches. American and Juan de Fuca Plates causes the vol- For a 3-dimensional view of a subduction zone, canoes of the Cascades in the Pacific Northwest. visit: http://oceanexplorer.noaa.gov/explorations/03fire/logs/sub- duction.html. On the western side of the Pacific Ocean, the Pacific Plate converges against the Philippine The junction of two tectonic plates that are mov- Plate and Australian Plate. Subduction of the ing apart is called a divergent plate boundary. Pacific Plate creates the Mariana Trench (which Magma rises from deep within the Earth and includes the Challenger Deep, the deepest known erupts to form new crust on the lithosphere. area of the Earth’s ocean) and the Kermadec Most divergent plate boundaries are underwater Trench. As the sinking plate moves deeper into (Iceland is an exception), and form submarine the mantle, new magma is formed as described mountain ranges called oceanic spreading above, and erupts along the convergent bound- ridges. While the process is volcanic, volcanoes ary to form volcanoes. The Mariana and and earthquakes along oceanic spreading ridges Kermadec Islands are the result of this volcanic are not as violent as they are at convergent plate activity, which frequently causes earthquakes boundaries. View the 3-dimensional structure of as well. The movement of the Pacific Ocean a mid-ocean ridge at: http://oceanexplorer.noaa.gov/ tectonic plate has been likened to a huge con- explorations/03fire/logs/ridge.html. veyor belt on which new crust is formed at the oceanic spreading ridges, and older crust is The third type of plate boundary occurs where recycled to the lower mantle at the convergent tectonic plates slide horizontally past each other, plate boundaries of the western Pacific. For more and is known as a transform plate boundary. As information on plate tectonics, visit the NOAA the plates rub against each other, huge stresses Learning Objects Web site (http://www.learningdemo. are set up that can cause portions of the rock com/noaa/). Click on the links to Lessons 1, 2 and to break, resulting in earthquakes. Places where 4 for interactive multimedia presentations and 2 New Zealand American Submarine Ring of Fire 2007 – 5-6 (Life Science/Earth Science) oceanexplorer.noaa.gov Focus: Ecological impacts of volcanism in the Mariana and Kermadec Islands Learning Activities on Plate Tectonics, Mid-Ocean html. You may also want to review portions of Ridges, and Subduction Zones. See the satellite “This Dynamic Earth” and/or “This Dynamic and sonar survey animation of the Mariana Arc Planet” (see Resources section). Volcanic Chain at: http://oceanexplorer.noaa.gov/explorations/04fire/background/ 2. Review the concepts of plate tectonics and con- marianaarc/media/sat_em_islands_video.html. tinental drift. Be sure students understand the idea of convergent, divergent, and transform Beginning in 2002, Ocean Exploration expe- boundaries, as well as the overall type of earth- ditions have undertaken systematic mapping quake and volcanic activity associated with and study in previously-unexplored areas of the each type of boundary (strong earthquakes and Submarine Ring of Fire. Visit explosive volcanoes at convergent boundaries; • http://oceanexplorer.noaa.gov/explorations/02fire/logs/ slow-flowing volcanoes, weaker earthquakes magicmountain/; at divergent boundaries; strong earthquakes, • http://www.oceanexplorer.noaa.gov/explorations/03fire/; rare volcanoes at transform boundaries). • http://www.oceanexplorer.noaa.gov/explorations/04fire/; Introduce the Ring of Fire and the New Zealand • http://www.oceanexplorer.noaa.gov/explorations/05fire/; American Submarine Ring of Fire 2007 and Expedition, and describe the processes that pro- • http://oceanexplorer.noaa.gov/explorations/06fire/welcome. duce the Mariana Arc. Tell students that there html was a major volcanic eruption on the Mariana for more information about the many discover- Island of Anatahan in 2003, a few months after ies, as well as still and video imagery, from the Ring of Fire Expedition completed its mis- these expeditions. The New Zealand American sion in the area. Have students read “Marianas Submarine Ring of Fire 2007 Expedition is eruption killed Anatahan’s corals,” and briefly focused on detailed exploration of hydrothermal discuss the events reported in the article. systems at Brothers Volcano in the Kermadec Arc, an area where tectonic plates are converging 3. Tell students that their assignment is to find at more rapidly than any other subduction zone in least three ways in which volcanic activity like the world. that on Anatahan could be beneficial to nearby ecosystems. Depending upon students’ internet Soon after the 2003 Ring of Fire Expedition left research skills and available time, you may the Marianas, a major volcanic eruption on the want to direct them to one or more of the fol- island of Anatahan buried the island in ash and lowing sites: dropped tons of sediment into nearby waters, resulting in massive coral deaths. Volcanic erup- http://www.pmel.noaa.gov/vents/index.html (NOAA’s tions are often viewed as disasters; but while hydrothermal vent Web site); these events are obviously destructive, volcanism http://www.cdnn.info/eco/e030910/e030910.html (article may also have ecological benefits. In this activity, about volcanic activity associated with students will explore some ways in which these the most developed reefs in the Northern terrifying events may be helpful to life on Earth. Mariana Islands); http://communications.uvic.ca/ring/98oct02/tunnicliffe.html LEARNING PROCEDURE (article about an eruption of the Axial under- 1. To prepare for this lesson, review the introduc- water volcano); tory essays for the New Zealand American http://www.the-conference.com/JConfAbs/5/415.pdf (article Submarine Ring of Fire 2007 Expedition at about the fertilization potential of volcanic http://oceanexplorer.noaa.gov/explorations/07fire/welcome. ash in ocean waters) 3 New Zealand American Submarine Ring of Fire 2007 – 5-6 (Life Science/Earth Science) Focus: Ecological impacts of volcanism in the Mariana and Kermadec Islands oceanexplorer.noaa.gov and clams.