- PHY 2251 – Lab 9 – SP17
Earthquake Investigation
Objective: To visualize the randomness of earthquakes and to use earthquake occurrences to map a fault boundary.
Background: An earthquake is the violent shaking of the Earth caused by the movement of tectonic plates, large pieces of Earth’s crust. When these plates move suddenly there is a large release of energy all at once, causing the Earth to shake. Earthquakes occur at a place called the focus, a spot underground where the plates move past one another. On the surface, the place directly above the focus is known as the epicenter.
Earthquakes are measured using the Richter scale. The Richter scale is a logarithmic scale that measures the energy released by an earthquake. Because it is a logarithmic scale, an earthquake that measures 5.0 on the Richter scale is 10 times stronger than one that measures a 4.0. Likewise, a 6.0 is 100 times stronger than a 4.0.
Procedure: In Part 1 of this experiment you will find information and create a graph that shows earthquakes occurring over time in a particular region. In Part 2, you will plot the epicenter of these earthquakes on a map.
Part 1: Choose a region from the list given below or another region prone to earthquake activity. No two groups should be using the same region.
California Japan Chile New Zealand
India China Romania Peru Turkey
After you have chosen a region for your group, investigate the earthquakes that have occurred in that region over the past 65 years (since 1950). Use any credible resources available. Use this information to fill in Table 1. For all earthquakes of magnitude 5.0 or greater, record the date, location (latitude and longitude) of the epicenter and the magnitude of the earthquake. Remember that some places are more active than others, so some groups may have more data than others, however you should have between 25 and 30 data points.
When you are finished, input this data into Excel and create a graph of Earthquake magnitude versus time. Be sure to title your graph, label the axes with name and units, and also mark any earthquakes that were greater than an 8.0. (Do this in Excel, do not just write it on the graph).
Include the graph in your lab report and answer the following questions in your conclusion:
1) Are all of the earthquakes of similar magnitude in one region, or do they change often? Remember that because the Richter scale is logarithmic, an 8.0 is much different from a 7.5. 2) Do you see any pattern in the occurrence of earthquakes? Do they occur at particular dates? Do they always occur in the same location? Look for patterns and discuss any you might find.
Part 2: Construct a map of the earthquakes’ location using Google Maps. This can be done by using the Google maps tool available at http://www.darrinward.com/lat-long/ or any other mapping tool that you can find. Input the latitude and longitude of each earthquake in your region. Pay attention to the directions. Always input latitude first (North is positive, south is negative) and then longitude (East is positive, West is negative) separated by a comma.
Print or save the map and include it in your lab report. Also, answer the following questions in your conclusion
1) When you look at the earthquakes on the map, what do you see?2) Remember that earthquakes occur along plate boundaries. Is there evidence for this on your map?
3) Investigate the plates nearby your region to determine the source of the seismic activity. Which plates are moving against which plates? What type of boundary (boundaries) are near your region?
4) Is there any other type of activity (volcanoes, large mountains) that occurs near your region that may also be attributed to plate movement?
