Exercise 32 Problems Part 2

Using the map of the Hawaiian Islands and the ages of the basaltic lava (Figure 32-4), compute the approximate rate of movement of the Pacific Plate as it passes over the Hawaiian hot spot. You will compare the age and distance between several different volcanoes on the islands. The ages of volcanic rocks on the islands are given in millions of years. White dots on the islands mark the location of a volcano. For example, on the island of Hawai‘i, the dot next to “0.0” marks the location of the currently active volcano, Kı-lauea. In this exercise, you will compare Hawai‘i (0.0 years—currently active volcanoes), Moloka‘i (1.9 million years), O‘ahu (3.7 million years), and Kaua‘i (5.1 million years). For the purposes of this exercise, we will take the position of the Kı-lauea volcano to represent the location of the Hawaiian hot spot (keep in mind that this is a simplistic assumption). We also assume that the Hawaiian hot spot is completely stationary over long periods of time.

Complete the chart on the following page: THIS CHART IS COMPLETE (Please see below)
(a) First, determine the distance between each pair of locations listed on the chart. With
a ruler, carefully measure the distance between locations on the map to the nearest
millimeter if you use S.I. units and to the nearest 1/16 inch if you use English
units. If you use English units, convert fractions of inches to decimals to make
other calculations easier (for example, 11
>8= 1.125). This figure is the “Measured Distance on Map.” Then multiply this measured distance on the map by 4,200,000
(the denominator of the fractional map scale) to determine the “Actual Distance”
in millimeters (or inches).
(b) Next, determine the “Age Difference” in years between each pair of locations. (Be
sure to include the correct number of zeros in your figure.)
(c) Finally, divide the “Actual Distance” between locations by the “Age Difference”
to estimate the rate of plate movement in millimeters (or inches) per year.