Physics of Geysers Dr. Christian Reimers Faculty of Earth Sciences, Geography and Astronomy University of Vienna Austria

Introductory section and preparatory phase Short Description: The Earth has a hot core and a mantle of molten rock on which the Earth's crust lies. Plate tectonics and volcanism is produced by convection. In places where the magma is near the surface, geysers can form, whose functionality can be explained with hands-on experiments and physical backgrounds. Keywords: structure of the Earth, geothermal energy, geysers, volcanism, thermodynamics, Clausius-Clapeyron‘s equation, vapour pressure curve, boiling point, P-T-diagram Target audience: school students, informal learners Age range: 12-15, 16+ Context: physics (thermodynamics), geography Time required: 2 x 50 min (more if visit in Science Center is planned)

Technical Requirements: PC, internet connection, physics labor Author’s background: Lecturer for Physics an Mathematics for Earth Sciences Connection with the curriculum: thermodynamics, structure of the Earth Learning Objectives: Behaviour of water with temperature and pressure; Study natural phenomenon with physical concepts Perform autonomously investigations; Writing a scientific report Guidance for preparation: Organise excursion to a Science Center with hands-on about volcanism and geysers Introductory section and preparatory phase

Teaching Phase 1: Question Eliciting Activities PROVOKE CURIOSITY > Teacher: Present and show materials to provoke curiosity Pictures / videos of volcanoes and geysers Highest fountains and other interesting data Types of volcanic activity: super volcanoes, etc.

Teaching Phase 1: Questions Eliciting Activities DEFINE QUESTIONS FROM CURRENT KNOWLEDGE > Teacher: Present questions according to current knowledge Where you can find volcanoes and/or geysers? How is the structure of Earth? Which mechanisms could explain volcanism and geysers? Which physical processes are involved? Do you know about volcanism on other planets or moons in the solar system? > Students: Collect data from previous presentation(s) and try to connect to questions raised above

Teaching Phase 2: Active Investigation PROPOSE PRELIMINARY EXPLANATIONS OR HYPOTHESES > Teacher: provide necessary materials (references) to be able to explain the questions; guide students to find the correct solving approaches Behaviour of water with temperature: solid, fluid, gas Temperature gradient in the Earth’s crust Water cycle: ground water, where it comes from > Students: Investigate materials and create presentation with possible answers and explanations and present to others

Teaching Phase 2: Active Investigation PLAN AND CONDUCT SIMPLE INVESTIGATION > Students: Search for physical concepts about volcanisms and geysers Physical concept: „Physik in interessanten Kontexten“ from Rainer Müller, page 39ff. „Der Ausbruch eines Geysirs“ (The eruption of a geyser) kiel.de/piko/downloads/Physik_in_interessanten_Kontexten_RMueller.pdf kiel.de/piko/downloads/Physik_in_interessanten_Kontexten_RMueller.pdf Experiments: „Versuchsbericht zum Thema: Schweredruck in Flüssigkeiten“ essen.de/veranstaltungen/soe/versuchsberichte/WS0809/Berichte/Versuchs bericht%20Schweredruck.doc > Students: Reflect and document findings > Teacher/Students: Prepare an experiment in the classroom or a visit to a science center with hands-on about volcanism and geysers

Teaching Phase 3: Creation GATHER EVIDENCE FROM OBSERVATION > Teacher/Students: Conduct experiment of a geyser model in the classroom and measure temperature and pressure Instructions: “Experiment Geysir“: Betriebsanleitung Geysir-Modell: „Druckabhängigkeit des Siedepunkts“ > Teacher/Students: or...

Teaching Phase 3: Creation GATHER EVIDENCE FROM OBSERVATION > Go to a science center (e.g. WELIOS in Wels, Austria) Topics about renewable Energies: Go to Geothermal Energy...

Teaching Phase 3: Creation GATHER EVIDENCE FROM OBSERVATION > Go to a science center (e.g. WELIOS in Wels, Austria) Earth globe you can open

Teaching Phase 3: Creation GATHER EVIDENCE FROM OBSERVATION > Go to a science center (e.g. WELIOS in Wels, Austria) Model of plumes and volcanic activity

Teaching Phase 3: Creation GATHER EVIDENCE FROM OBSERVATION > Go to a science center (e.g. WELIOS in Wels, Austria) Experiment of a geyser > Students: Create protocol of observations and physical measurements The geyser starts, when: the temperature reaches about 103 degree Celsius and the pressure excess is 0.15 bar

Teaching Phase 4: Discussion EXPLANATION BASED ON EVIDENCE > Students: Analyse data and discuss them together. Behaviour of water: boiling, evaporating, phase transistion Pressure  temperature: Clausius-Clapeyron’s relation boiling point  pressure vapour pressure curve

Teaching Phase 4: Discussion CONSIDER OTHER EXLANATIONS > Teacher: Ask if there are other explanations possible Geysers or water fountains without heat: Cold water geysers with CO2, carbon dioxide-driven (e.g. Andernach, Germany) Artificial fountains with pumps Water hydrants (water supply) Associated vessels > Students: Think about and discuss

Teaching Phase 5: Reflection COMMUNICATE EXPLANATION > Students: Write a scientific report on the physical aspects of a geyser: phases of an eruption, P-T-diagram; use guidelines for writing a scientific report : > Structure (title, abstract, introduction, etc.) Layout (font, headings, enumerations, etc.) > Teacher: Assess and discuss scientific report(s) as referee and guide students to publish refereed report in learning management system of the school > Students: Create quizzes and questions for self assessment and publish

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