General Geology Lab #2: Natural Disasters Related to Tectonics
Name__________________________________
Before we begin with the computer exercises, let’s review earthquakes and volcanic phenomena and
another related hazard, tsunamis.
1) List the six main plate boundaries:
2) When continental crust abuts oceanic crust, and it is NOT associated with a plate boundary, what
is this type of boundary/margin called?
3) What conditions are necessary for an earthquake to occur?
4) At what types of plate boundaries are volcanoes common?
5) What type of tectonic activity is a common cause of tsunamis? (be specific)
Plate Boundaries, Volcanoes and Earthquakes
The program Seismic Eruption has been loaded onto the PCs in Olney 521. Log on to the computer as a
student, Password: student. When the computer finishes initializing, open the program by doubleclicking on the Seismic Eruption icon on the computer’s desktop. Enter the program by clicking “Start”
and “Go” at the appropriate prompts. Once in, you’ll see a map of the world with various labeled locations.
To complete this exercise, go to the locations and answer the related questions.
http://bingweb.binghamton.edu/~ajones/#Seismic-Eruptions
EARTHQUAKES AND VOLCANOES IN THE USA
6) Which US state do you think has experienced the most earthquake and volcanic activity over the
past fifty years?
AFTER you answer question 6, click on the North America Group, then North America
7) What state in the US has experienced the most earthquake and volcanic activity from 1959 to the
present? Did it match your answer in question 1? Why do you think we don’t hear more about
earthquakes and volcanism in this area?
CONVERGENT BOUNDARIES
Click Back until you return to the North America Menu Window
Click on Alaska Group  Cook Inlet
This is a convergent plate boundary where subduction of oceanic lithosphere is occurring. Observe the
trends of earthquake depths by noting where the colors corresponding to shallower and deeper
earthquakes are occurring. Plates go deeper as they subduct.
8) Toward which direction is the plate subduction occurring?
Click on Back to return to the Alaska Menu, then click on Cook Inlet 3D and then Cook Inlet Crosssection to see how you did with your answer to question 3. Note the diagonal orientation of the line of
earthquakes roughly showing the surface of the downgoing slab.
9) To what depths do these earthquakes reach?
10) Why aren’t there any deeper earthquakes? (think about where earthquakes occur in a broad
sense and the types of material involved)
11) Particularly on the Cook Inlet Cross-section, you will see a few shallow earthquakes to the west
above the slab. What might have caused these? (Think about it before clicking on the info
button.)
Click Back until you return to the World Menu Window
Click on Asia Group  Asia
12) Compare the seismic activity (volcanoes, earthquake intensities and depths) in the area along
the northern border of India with those off the eastern coast of Asia in the area around Japan.
Biefly describe how these collisional boundaries differ and how this is reflected by the nature of
the seismic activity experienced by both areas.
TRANSFORM BOUNDARIES
Click Back until you return to the World Menu Window
Click on North America Group  United States Group  California Group  Southern California
Group  Southern California-1992
13) There are many pale yellow lines representing faults shown on this map. After observing where
the majority of the quakes occurred, do you think all of the faults in the area have been mapped?
Why or why not?
DIVERGENT PLATE BOUNDARIES—MID-OCEAN RIDGES
Click Back until you return to the World Menu Window
Click on Atlantic Group  Atlantic Ocean
14) Examine the earthquakes associated with the Mid-Atlantic Ridge. In general, how deep and how
strong are most earthquakes associated with the Mid-Atlantic Ridge boundary? (If it helps,
change the EQ cutoff to 7 or 6 and hit the repeat button to see how common these stronger
earthquakes are.)
GLOBAL DISTRIBUTION OF PLATE BOUNDARIES
Still looking at the Atlantic Ocean
15) How common is earthquake activity around the coastlines of the Atlantic Ocean?
Now click to remove the checkmark from the Earthquakes box and place one in the Eruptions box, then
click Repeat button.
16) How common is volcanic activity around the coastlines of the Atlantic Ocean?
17) Summarize the types of plate boundaries that exist within and around the Atlantic Ocean. What
type, if any, tectonism (earthquake and volcanic activity) is associated with these margins?
Click Back until you return to the World Menu Window
Click on Pacific Group  Pacific Ocean
Look at the earthquake activity around the Pacific then reset the controls to view eruptions just as you did
for the Atlantic Ocean.
18) Summarize your findings on the tectonism and types of plate boundaries that exist within and
around the Pacific Ocean. How does tectonic activity in and around the Pacific Ocean compare
to that in the Atlantic Ocean?
TSUNAMIS
19) Knowing that tsunamis are typically generated by earthquakes of 7.5 or greater magnitudes, that
are associated with an up-down plate motion, based on your above observations regarding
seismic activity, what type of plate boundary would most likely produce them?
Based on your answers to questions 7, 8, 9 and 13 above:
20) Name two areas of the United States that are under proximal threat of a tectonically-produced
tsunami (i.e. they are close to that type of plate boundary).
21) Because tsunamis can travel great distances across an ocean, name two areas of the United
States that are under a distal threat of being hit by a tectonically-produced tsunami.
22) Should people along the east coast of the US should take out tsunami insurance? Why or why
not?
DETERMINING EARTHQUAKE LOCATION AND MAGNITUDE
Open Internet Explorer and go to the Virtual Earthquake site bookmarked under:
http://www.sciencecourseware.org/VirtualEarthquake/VQuakeExecute.html
1) Read through the information on the website and follow the directions to determine the epicenter
location and the magnitude for ONE of the regions. Print out the epicenter and then write the
magnitude in the available space below the map, once you have determined it. Print out and
attach the map to your lab write-up and include the location and magnitude of the other
earthquake you chose (if working together, each student needs an attached map with location
and magnitudes of two earthquakes).
Earthquake Location:
Magnitude: