Hotspot Lesson: Samoan Hotspot
This material is replicated on a number of sites as part of the SERC Pedagogic Service Project
Context for Use
Description and Teaching Materials
This lesson begins with an introduction to Hotspots Chains using the Hawaiian Volcanic chain. The Samoan Islands are then introduced and a comparison drawn to the Hawaiian chain. This introduction can be given using the Samoa Introductory Lecture PowerPoint.
The activity is motivated by two questions:
The instructor then divides the students into groups and assigns each group two seamounts or islands. The students calculate the age of the seamount using plate velocities from the previous activity on Hotspot Theory and Plate Velocities or the accepted velocity of 7 cm/year. The Samoa Activity Sheet walks them through the assignment. The Samoa Activity Instructions provides the data and template for the students to carry out the activity.
The activity concludes with a whole class discussion. The students share their data and create an integrated data table. This data set can later be compared to actual age information calculated from Samoan samples given in Samoan Calculated Age Table. The students can then return to the motivating questions and discuss the origin of the Samona islands.
The Samoa Data Collection PowerPoint can be used to give students an idea of what kind of effort goes into doing research on island chains and seamounts.
Teaching Notes and Tips
It is important to note that this is not entirely correct to use the velocity calculated using Hawaii data for Samoa because Hawaii is located far to the north of Samoa. Since the earth is spherical, latitude needs to be taken into account in determine angular rotations but for the scope of the class it was necessary to assume that the same velocity could be use.
Remember that the student values will not match those in the published data table if they use a velocity different that 7 cm/year.
Group participation and class participation can be assessed as well completion of the activity sheet.
This lesson ends with a Take Home Examine. This exam asks the students to compare two data sets of age data from Samoa. One graph is composed of ages collected prior to the data Jamie collected and the other graph including the new results. This exam evaluates the students understanding of some critical points from the weeks lectures.
References and Resources
Lesson MaterialsSamoa Introductory Lecture PowerPoint
Samoa Activity Sheet
Samoan Calculated Age Table
Samoa Activity Instructions
Additional Samoa Data Collection PowerPoint
Take Home Examine
ERESE Resource MatricesFormation of Seamounts
Hotspots and Plate Motion