Lab 4.2 – Don’t volcanoes erupt UP?

Estimated time to complete: 45 minutes
Materials needed: none

Examine the Earthquake data included in graphs 2 and 3 keeping all data viewable. 

Note that Earthquake depth in the second figure plots depth down into the lithosphere on the y-axis; you might be more familiar with greater values being plotted above the x-axis.  This approach is done to help readers visualize the location of earthquakes at greater depths.

  1. Describe the patterns in each and compare patterns in both graphs and to the water depth plot.
  2. Considering the combination of seafloor depth and earthquake data, what do you think happened on or about April 24th, 2015?
  3. What do you think might explain the difference between the number of earthquakes before and after the eruption?
  4. How might the movement of the magma in the subsurface within the volcano influence the behavior of the earthquakes before, during, and after the eruption? How might the movement of the magma influence the bathymetry (seafloor topography)?
  5. After discussing in class, write your own explanation for the trends and patterns in the data.

Assessment questions

  1. Adjust the widget to show pressure data for the time span that includes only March 15 through March 22. Describe the pattern(s) you see in each of the graphs.
  2. What do you think might explain the patterns you’ve noted? What background from this lab might be useful in trying to explain them?