Exploring Earth's Plate Boundaries

In this topic, we'll use the Jules Verne Voyager Jr. to explore global plate motions. The JVV Jr. allows you create individualized maps, combining a variety of base maps, satellite imagery, and geological information with overlays illustrating earthquake and volcanic activity, measured GPS crustal motions, and models of plate motion.

The JVV Jr. opens with a global image of the Earth, using a special composite satellite image of the entire land area of the plant, combined with a detailed bathymetric map of the Earth's sea-floor depths. It also shows a simplified version of the world's plate boundaries superimposed on the map image.

Activity 1

With the JVV Jr. open, create a map according to the specifications below (go through them in order). You'll be adding a tectonic plate boundary overlay to the Face of the Earth & Relief map.

Clear any previous settings: Click on the World Map button. Then select the Face of the Earth & Relief base map, No Features, and No Velocities. Click on Make Changes.
Feature(s): Select Tectonic Plates, then click on Make Changes

Looking at your new map, trace your way along the global system of plate boundaries. Referring to the map below, become familiar with the names of the plates that they separate. (For a larger version of the map, access NASA's map of tectonic plates.) Use the following questions to guide your exploration of the JVV Jr. map. According to the maps:

  1. Which appears to be the largest plate on the Earth? Where is it located?
  2. Which appears to be the smallest plate? Where is it located?
  3. What plate appears to have the largest percentage of oceanic crust? What is the percent?
  4. What plate appears to have the largest percentage of continental crust? What is the percent?
  5. What plate(s) does New Zealand reside on?
  6. What plate(s) comprise the continent of Eurasia?

Open Table 1 and print it out. (You will need to enter the information manually on the printed copy.) For each of the 13 major plates listed, enter the names of the neighboring plates, the types of boundaries linking it to the neighboring plates (convergent, divergent, or transform), and the characteristic crust type (% continental vs. oceanic). Leave the Estimated Motion column blank for now.

Activity 2

Base map: Same (Face of the Earth & Relief)
Feature(s): Keep Tectonic Plates selected. Also select Political Lat/Long to turn on the latitude-longitude grid. (To make multiple selections, hold down the CTRL key on PCs and the Command key  on Macs). Click on Make Changes.

Geographers use the system of latitude and longitude to uniquely define position on the surface of the Earth. (Click if you want to review more detailed background information on latitude and longitude before proceeding.)

Answer the following questions as you look at the map:

  1. What is the approximate latitude and longitude of the easternmost point on the North American continent? The North American plate?
  2. What is the approximate longitude of the Antarctic Peninsula?
  3. What is the latitude of the northermost point on the Antarctic Plate?

Activity 3

Base map: Same (Face of the Earth & Relief)
Feature(s): Same (Tectonic Plates and Political Lat/Long)
Zoom: You'll be zooming in on different regions of the map. (To zoom in, click directly on the map; to zoom out, click on the Zoom Out button.)

Plate boundary processes are often expressed in the physiography (shape of the land surface) of the Earth. Use the Zoom function to focus in on the following plate boundaries:

  1. A mid-ocean ridge: The northern mid-Atlantic Ridge (lat. 60°N lon. 330°E)
  2. A subduction zone: The Japanese islands (lat. 35°N lon. 140°E) (Hint: Look carefully at the depth of the sea floor near Japan!)
  3. A continent-continent collision zone: The Himalayas (lat. 30°N lon. 80°E)
  4. An oceanic strike-slip fault: The Gibbs Fracture Zone, North Atlantic Ocean (lat. 52°N lon. 328°E)

Describe each plate boundary in terms of the following and enter the information in Table 2.

Activity 4

Base map: Same (Face of the Earth & Relief)
Feature(s): Same (Tectonic Plates and Political Lat/Long)
Zoom: You'll be zooming in on different regions of the map.

Describe two other areas of this remarkable image of the surface of the Earth that you find interesting. Make up a hypothesis to explain them. (There's no 'correct' answer!)

Look at the unusual shape of the sea floor around the Arctic Ocean, the Bering Sea, or the South Pacific; or the land area in central Eurasia, the western third of North America, or the Appalachians.