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CCOG for G 208 Fall 2022

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Course Number:
G 208
Course Title:
Volcanoes and Their Activity
Credit Hours:
Lecture Hours:
Lecture/Lab Hours:
Lab Hours:

Course Description

Covers the origin, activity, products, classification, and hazards of volcanoes. Prerequisites: (WR 115 and RD 115) or IRW 115 and (MTH 58 or MTH 65) or equivalent placement. Audit available.

Addendum to Course Description

Volcanoes and Their Activity (G 208) is a one-term introductory course in volcanology, which is a branch of the science of geology. The student will develop an understanding of the types, origin, activity, products, and hazards of volcanoes.

Students are expected to be able to read and comprehend college-level science texts and perform basic mathematical operations in order to successfully complete this course

Field Based Learning Statement

Earth and space sciences are based on observations, measurements and samples collected in the field. Field-based learning is recommended by numerous professional Geology organizations, including the American Geological Institute and the National Association of Geoscience Teachers. Field-based learning improves both metacognition and spatial/visualization abilities while helping to transfer basic concepts to long-term memory by engaging multiple senses at the same time. Spatial thinking is critical to success in STEM (Science, Technology, Engineering, and Math) disciplines. Field work may include:

  • Developing skills in site characterization
  • Application of key terms and concepts
  • Measurement and data collection
  • Interpretation of data and observations, and fitting them to a larger context

Field work may be physically challenging and may require overland travel on foot or other means to field sites, carrying equipment and supplies, and making measurements in unusual or awkward positions for a length of time.  Field work may include inherent risks (uneven terrain, variable weather, insects, environmental irritants, travel stress, etc.). Field work can be adapted to individual abilities.

Creation Science Statement

Regarding the teaching of basic geologic principles (such as geologic time and the theory of evolution), the Portland Community College Geology/General Science Subject Area Committee stands by the following statements about what is science.

  • Science is a fundamentally non-dogmatic and self-correcting investigatory process. A scientific theory is neither a guess, dogma, nor myth. The theories developed through scientific investigation are not decided in advance, but can be and often are modified and revised through observation and experimentation.
  • “Creation science,” also known as scientific creationism, is not considered a legitimate science, but a form of religious advocacy. This position is established by legal precedence (Webster v. New Lenox School District #122, 917 F.2d 1004).
  • Geology/General Science instructors at Portland Community College will teach the generally accepted basic geologic principles (such as geologic time and the theory of evolution) not as absolute truth, but as the most widely accepted explanation for our observations of the world around us. Instructors will not teach that “creation science” is anything other than pseudoscience.
  • Because "creation science", "scientific creationism", and "intelligent design" are essentially religious doctrines that are at odds with open scientific inquiry, the Geology/General Sciences SAC at Portland Community College stands with such organizations such as the National Association of Geoscience Teachers, the American Geophysical Union, the Geological Society of America, and the American Geological Institute in excluding these doctrines from our science curriculum.

Intended Outcomes for the course

Upon completion of the course students should be able to:

  1. Explain the igneous processes which formed individual rock and mineral specimens using an understanding of rock and mineral characterization and classification.
  2. Explain the geographic distribution of the Earth’s volcanic activity using an understanding of plate tectonics. 
  3. Relate the Earth’s volcanic activity to climate change, geothermal energy resources, soil fertility, and the formation of economic deposits.
  4. Evaluate the volcano-related hazards and risks impacting our communities using scientific reasoning based on field and/or laboratory and/or remote measurements and observations. 
  5. Assess the contributions of volcanology to our evolving understanding of global change and sustainability while placing the development of volcanology in its historical and cultural context.

Quantitative Reasoning

Students completing an associate degree at Portland Community College will be able to analyze questions or problems that impact the community and/or environment using quantitative information.

General education philosophy statement

Geology and General Science Courses develop students’ understanding of their natural environment by introducing students to Earth, its processes, and its place in the larger scale of our solar system, galaxy, and the universe. Students learn how: • Earth is related to other terrestrial planets, • Plate tectonics drives volcanism and seismicity, • Surfaces and atmospheres evolve through time, setting the stage for the origin of life as well as mass extinctions, • Earth’s climate has changed via natural astronomical cycles interacting with the earth system’s (atmosphere, hydrosphere, cryosphere, lithosphere, and biosphere) in the past and is changing presently due to anthropogenic causes. Students gain an appreciation for geologic time and the rate of Earth processes and learn the methods used by scientists to observe and study our planet and the universe beyond. Students are introduced to the foundational concepts of how to apply quantitative and qualitative reasoning skills to solve Earth and Space science problems, and they gain an appreciation for the processes that operate at these spatio-temporal scales. Students learn how internal and surficial Earth processes impact society giving them the context to better understand natural hazards, energy and resource distribution, and impact of humans on our habitat to participate in societal discussions and decisions about these topics in a responsible manner.

Course Activities and Design

The material in this course will be presented in a lecture/discussion format Other educationally sound methods may be employed such as guest lectures, field trips, research papers, presentations, and small group work.

Outcome Assessment Strategies

At the beginning of the course, the instructor will detail the methods used to evaluate student progress and the criteria for assigning a course grade. The methods may include one or more of the following tools: examinations, quizzes, homework assignments, research papers, small group problem solving of questions arising from application of course concepts and concerns to actual experience, oral presentations, or maintenance of a personal work journal.

Course Content (Themes, Concepts, Issues and Skills)

  1. Describe the relationship of volcanoes to plate boundaries
  2. Classify the types of rocks created by volcanic processes
  3. Contrast pyroclastic and effusive eruption styles
  4. Examine the effect of silica content on eruption style
  5. Discuss a number of historical volcanic eruptions and determine the major cause of human destruction for each case
  6. Explore the methods used to forecast volcanic eruptions
  7. Classify the features that occur in volcanic landscapes
  8. Define the different kinds of plutons
  9. Discuss the hazards associated with the Cascade volcanoes
  10. Define the following terms: shield volcano, composite volcano, cinder cone, lahar, pyroclastic flow, pahoehoe, aa
  11. Discuss the effects of volcanic eruptions on climate

Topics to be covered include:

  1. Global Volcanic Activity
    1. Number and geographic distribution of active volcanoes
    2. Major historic volcanic eruptions and their impact on society (e.g. Tambora, Krakatau, Vesuvius, Mount Saint Helens)
    3. Active vs. dormant vs. extinct volcanoes
  2. Volcanic Eruptions
    1. Different styles of volcanic eruptions: effusive vs. explosive, Icelandic, Hawaiian, Strombolian, Vulcanian, Plinian and caldera type; lava flows, lava domes, eruption columns, pyroclastic flows, lahars, lateral blasts, landslides
    2. Phreatic eruptions vs. magmatic eruptions; submarine eruptions; sub glacial eruptions
    3. Sizes of volcanic eruption, VEI
  3. Volcanic Features
    1. Volcanic systems: volcanoes, vents, fissures and magma chambers
    2. Types of volcanoes: cinder cones, domes, shield volcanoes, stratovolcanoes, lava plateaus, calderas, maars, tuff rings
    3. Intrusive features; stocks, necks, cyptodomes, sills, dikes, plutons, batholiths.
    4. Volcanic features in the Portland area, Cascades, Columbia River Basin and eastern Oregon
  4. Products of Volcanic Eruptions
    1. Chemistry of magmas: major elements and volatiles; physical properties of magmas: freezing temperature and viscosity; relationships between magma chemistry and physical properties
    2. Relationship between cooling rate and igneous rock textures
    3. Description and classification of igneous extrusive rocks: rhyolite, dacite, andesite, basalt, scoria, pumice, obsidian, vesicles, porphyritic texture
    4. Description and classification of igneous intrusive rocks: granite, granodiorite, diorite, gabbro, peridotite
    5. Lava flow features: pahoehoe vs. aa, lava tubes, cooling columns, tree casts, pillows, palagonite breccias etc.; identifying lava flow tops and bottoms in the field
    6. Pyroclastic products: ash, lapilli, cinders, bombs, tuffs, welded tuffs, flow tuffs
    7. Gases: types, quantity; sources: meteoric vs. magmatic.
    8. Lahars: dynamics, distance and speed of flow, temperature; causes
    9. Pyroclastic flows: dynamics, distance and speed of flow, temperature, deposits, causes
    10. Lateral blasts: dynamics, distance and speed of flow, temperature, deposits, causes
    11. Landslides: dynamics, distance and speed of flow, temperature, deposits, causes
  5. Causes of Volcanic Eruptions
    1. Migration of magmas to shallow magma chambers, cooling and differentiation of magma chambers, differences between mafic and felsic magma chambers
    2. Role of exsolved gasses in driving volcanic eruptions
  6. Plate Tectonics and Volcanism
    1. Basic idea of plate tectonics, evidence for plate motion, difference between continental and oceanic crust, internal structure of the earth, heat loss and plate tectonics
    2. Creation of oceanic crust at mid ocean ridges, volcanism and hydrothermal activity at mid ocean ridges, cause of melting at mid ocean ridges, types of magmas produced
    3. Destruction of oceanic crust at subduction zones, volcanism associated with subduction zones, cause of melting at subduction zones, types of magmas produced
    4. Hot spots and associated volcanism in oceanic and continental settings, cause of melting, types of magma produced,
    5. Relationships between tectonic setting, cause of melting, magma type produced and eruption style
  7. Living with Volcanoes
    1. Volcanic hazards: lava flows, volcanic gases, eruption columns, ash falls, pyroclastic flows, lahars, landslides, lateral blasts.
    2. Volcanic hazard mapping: use of volcanic deposits to determine past eruptive behavior and frequency of volcanoes, identifying hazard zones
    3. Preparing for volcanic eruptions; personal disaster kits, volcano monitoring, evacuation plans, effective communication of scientific information, education of public
    4. Predicting volcanic eruptions: monitoring precursors (earthquakes, deformation, gas emissions): possible triggers
    5. Case studies of volcanic eruptions including successful (e.g. Mt. Pinatubo) and unsuccessful (e.g. Nevado del Ruiz) societal responses with an emphasis on Cascade volcanoes
    6. Resources associated with volcanoes: geothermal energy, hot springs, tourism, volcanic soils, mineral deposits, diamonds
  8. Global Impacts of Volcanism
    1. Climate changes associated with historic eruptions, causes of these changes
    2. Flood basalt volcanism: Columbia River Basalts and other large igneous provinces
    3. Possible links between volcanism and mass extinctions
    4. Volcanic degassing as a possible source of the atmosphere and ocean