In this activity students familiarize themselves with some basic concepts of volcanology and investigate a portion of the Ring of Fire. They then research the answers to questions on the provided worksheet. As a result of this activity students will be able to describe the processes that produce the "Submarine Ring of Fire," explain the factors that contribute to explosive volcanic eruptions, identify at least three benefits that humans derive from volcanism, describe the primary risks posed by volcanic activity in the United States, and identify the volcano within the continental United States that is considered most dangerous. Educational levels: Middle school