Integrating Research and Education > EarthChem > Central America Volcanoes > Part 2 - Volcano morphologies

# Part 2 - Volcano morphologies

Now you'll make a series of plots using the data from the CAGeochem.xls file which focus on the heights and volumes of the volcanoes along the Central American arc, and their relation to variations in crustal thickness along the arc.
1. Start by making an x-y plot of Distance (along the arc) on the x-axis vs. Volcano Height on the y-axis. Describe the trend in volcano heights along the arc. In which portions of the arc are the highest peaks located?
2. Now make a plot of Distance (x-axis) vs. Crustal Thickness obtained from geophysical surveys (y-axis). Is the thickness of the crust the same along the Central American arc, or does it vary? If it varies, what is the range of thicknesses, and where are the thickest and thinnest portions of the crust along the arc?
3. Now make a plot of Crustal Thickness (x-axis) vs. Volcano Height (elevation) (y-axis), and a plot of Crustal Thickness (x-axis) vs. Edifice Height (y-axis). Is there a correlation between how thick the crust is below the volcanoes and the elevation and heights of those volcanoes?

Your answer should not be too surprising, since the heights of the volcanoes necessarily add to the thickness of the crust beneath them! But is the range in crustal thickness along the arc entirely explained by the range in volcano heights along the arc? Can you think of another reason why thick crust would be higher in elevation than thin crust?
4. Finally, make a plot of Distance (x-axis) vs. Volcano Volume (y-axis). For the purposes of this plot, we will assume that minimal erosion has occurred. Is there any trend in volcano volume along the arc?