Activity: Plot Current Earthquake Data
ISCI 2001
Materials
You will need either a small world map to plot the earthquakes individually or in a small group OR a large world map to
plot the earthquakes as a class. If you do not have a map, you can download a map from the National Geographic
Xpeditions web site: (provided by your instructor)
o
o
Large World Map (.pdf format)
Large World Map (.gif format)
Instructions:
1. Click on one of the web sites listed below to see all of the earthquakes that have occurred over the last few days
which were larger than 2.5 on the Richter Scale. Note that in the first two columns you will see the time and date for
each earthquake. Note that in the second two columns you will see the latitude and longitude coordinates for the
epicenter of the earthquake. (provided by your instructor)
o TEXT-BASED (Recommend)
 USGS Earthquake Bulletin ()
NOTE: Magnitude Greater Than 2.5 Earthquakes From Around the World

IRIS List of Earthquakes (last 30 days)
NOTE: a latitude of + corresponds to degrees North and a latitude of - corresponds to degrees South
a longitude of + corresponds to degrees East and a longitude of - corresponds to degrees West
o
INTERACTIVE MAPS
 USGS
 Recent earthquakes with tectonic plate boundaries (last 7 days)
 Recent earthquakes (last 7 days)

IRIS Seismic Monitor
2. Use the latitude and longitude coordinates to plot a dot on your world map which represents the epicenter of the
earthquake. Use a blue pen if the earthquake occurred near the surface (less than 100 km) and use a red pen if it
occurred deep (greater than 100 km) in the earth (you will see the depth measurements in the table.)
NOTE: You can use the links that appear in the last column of the table to assist you in finding the locations of the
earthquakes if using the latitude and longitude coordinates is too difficult.
3. Begin with last week (10/22). Do this for a period of one more week .
4. After you complete collecting your data and plotting the earthquakes, please answer the following questions on another
sheet of paper.
(a). On which ‘plate’ did the greatest numbers of the earthquakes occur greater than 4.0 on the richter scale?
(b). Complete the table below and show the occurrences of earthquakes in each plate area (Eurasian, Indo-Australian, Pacific,
Juan de Fuca, North American, South American, Nazca, Antarctic, African). Determine the percentages of quakes that
occurred in that area.
(Add up the total number of earthquakes that occurred greater than 2.5 magnitude. The data sheets will include all magnitudes
of quakes above 2.5. Take each plate and determine the number of quakes that occur there. Divide by the total number of
quakes. Example: North American plate (quakes = 10/77 x 100 = 13% total quakes) during the 2 week period)
Plate
1. Eurasian
2. IndoAustralian
3. Pacific and
Juan de Fuca
4. Antarctic
5. Nazca
6. North
American
7. South
American
8. African
Number of Quakes above
2.5
Percentage of Total Quakes
during
9. Eurasian
(c). Make an appropriate graph to show your results (may plot % or number of occurrences)
(c). From what you have learned about Earthquakes, do the results surprise you or is this what you expected? Explain.