6.1: Introduction
Module 6
Volcanism
Introduction
In the previous module, we studied different types of igneous rocks and intrusive igneous processes. Now, we are moving on to consider volcanism and extrusive activity. Without doubt, volcanic eruptions are among the most spectacular of Earth’s processes. Activity ranges from gentle eruptions that do not represent significant hazards to humans, as is the case in Hawaii, up to highly explosive and large events that have the potential to impact global climate. In this module, you will learn about the different types of volcanism and the hazards that they represent. In addition, you will read about several specific volcanoes to better understand the processes associated with different eruptions.
How would you like to live on an active volcano? Surprisingly, a lot of people are living on or near active volcanoes, and many more live near volcanoes that are currently considered to be “dormant,” exhibiting a volcanically-quiet period of time over the past 10,000 years, but with the potential to erupt in the future. Are they crazy? Maybe some are, but not all volcanoes erupt explosively; for example, the type of volcano that forms the Hawaiian Islands is a type that erupts effusively, with lava running down the sides (flans) of the volcano. Hawaiian citizens are familiar with this style of eruption, and they are also aware that their particular volcano will not erupt explosively.
Explosive eruptions are more likely for the volcanoes that make up the Islands of Sumatra and Java (Indonesia); these volcanoes are very dangerous, and yet Indonesia is one of the most densely populated countries in the world. So, it would seem very important to know why some volcanoes are dangerous, and why others are not. Of the “dangerous” types that are currently dormant, will we have enough of a warning before they erupt? Is it only the eruption that we should worry about, or are there other hazards that we must be aware of? These questions will be addressed in this module, along with a few other questions that you might have, such as why volcanoes form in certain locations, especially in relation to plate tectonics, and the association of magma type with volcano type and eruptive style.
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Module Objectives
At the completion of this module you will be able to:
- Describe the different types of volcanoes.
- Explain why there are different types of lava.
- Explain how volcanism, igneous rocks and plate tectonics relate.
- Describe the hazards associated with volcanism.
- Explain how volcanism can impact life on Earth.
Activities Overview
See the Schedule of Work for dates of availability and due dates.
Be sure to read through the directions for all of this module’s activities before getting started so that you can plan your time accordingly. You are expected to work on this course throughout the week.
Discussion 3
30 points, class participation
For this week’s “Current Events in Geology” discussion. It is important that you feel engaged in this class. Discussion topics are very flexible, and can cover anything in geology or a related field, including hydrology or water resources, environmental or climate science, paleontology, planetary geology, etc. This is a great opportunity for you to learn about topics in geology that interest YOU, and to see that many interesting things relating to geology are currently making headlines in the news. You are also helping your instructor to become aware of what is going on and to learn new things, so I appreciate your efforts and look forward to reading what you find!
Pay close attention to the Course Schedule for when each of your posts are due. Some are due earlier than others. Failure to post on time will result in lost points.
Module 6 Assignment: Exploring Volcanic Features of the United States
15 points
After you complete the reading, you can start working on Module 6 Assignment – Volcanic Features of the United States
Module 6 Quiz
10 points
Module 6 Quiz has 10 multiple-choice questions and is based on the content of the Module 6 readings and Assignment 6.
The quiz is worth a total of 10 points (1 points per question). You will have only 10 minutes to complete the quiz, and you may take this quiz only once. Note : that is not enough time to look up the answers!
Make sure that you fully understand all of the concepts presented and study for this quiz as though it were going to be proctored in a classroom, or you will likely find yourself running out of time.
Keep track of the time, and be sure to look over your full quiz results after you have submitted it for a grade.
Your Questions and Concerns…
Please contact me if you have any questions or concerns.
General course questions : If your question is of a general nature such that other students would benefit from the answer, then go to the discussions area and post it as a question thread in the “General course questions” discussion area.
Personal questions : If your question is personal, (e.g. regarding my comments to you specifically), then send me an email from within this course.