web.ics.purdue.edu/~braile Online Searches

Plotting Earthquake Epicenters Create a plot of worldwide earthquake epicenters to display the narrow zones of seismic activity of the Earth and aid in an understanding of plate tectonics. Students discover that about 95% of earthquakes occur along plate bound- aries where the lithospheric plates (about 100 km thick shell of relatively cool, rigid and brittle rock overlying the softer, hotter asthenosphere zone with- in the Earth’s upper mantle) move with respect to each other in three ways  diverging or moving apart (such as at the mid-ocean ridges), converging or colliding (such as along the west coast of South America, the Aleutian Islands, or the western Pacific) and transform or horizontal slipping (such as along the San Andreas fault in California).

Information on catalog searches to obtain and earthquake list:

Base map (full version is 11x17 inches) for plotting epicenter from an earthquake list.

It is useful to initially perform the epicenter plotting activity "by hand." The experience allows the student to fully understand the characteristics of the data, learn how to obtain real and timely earthquake data from the Internet, and practice map skills, including longitude and latitude, directions, two-dimensional interpolation, and basic world geography. Extensions to this activity are described that include producing maps with computer software or from the Internet. Close-up of example epicenter map, self- adhesive, color dots used to plot epicenters

Section of wall map with colored dots indication earthquake epicenters

IRIS Event Search for CA/NV Earthquakes

Results:

IRIS Event Search for CA/NV Earthquakes - Map

Legend for Plotting CA/NV Epicenters Magnitude <

Seismic/Eruption Seismic/Eruption includes up-to-date earthquake and volcanic eruption catalogs and allows the user to display earthquake and volcanic eruption activity in “speeded up real time” on global, regional or local maps that also show the topography of the area in a shaded relief map image. Seismic/Eruption is an interactive program that includes a number of tools that allow the user to analyze earthquake and volcanic eruption data and produce effective displays to illustrate seismicity and volcano patterns.