Earthquakes Japan's Big One! Comparing Magnitudes Debra.woodall@daytonastate.edu Japan's Big One! Comparing Magnitudes

Locating the source of earthquakes Earthquake patterns Definite patterns exist Most earthquakes are associated with plate boundaries

Most seismic activity occurs at the areas between tectonic plates Most seismic activity occurs at the areas between tectonic plates. The dots above display earthquakes with a minimum 5.5 of movement measured by the Richter scale. All the above earthquakes above have taken place since 1973 TO 2004

Locating the source of earthquakes Earthquake patterns Definite patterns exist The depth of earthquake focus can often be associated with plate boundary type Shallow earthquakes occur at divergent boundaries Almost all deep-focus earthquakes occur at convergent boundaries landward of deep-ocean trenches

This is a convergent boundary This is a convergent boundary. Do you see how the deeper earthquakes are associated with the subducting plate? Now, let’s go to the IRIS Earthquake Browser and explore earthquake patterns…

Student instructions… The Discussion was created to give you the chance to use some of the terminology and knowledge you’ve gained from your slides. Review the IRIS Earthquake Browser Instruction Video to help you with this Discussion assignment. Then Open the IRIS Earthquake Browser, explore the world of earthquakes and select on a region you are particularly interested in learning more about. Following the instructions, take a pic while using the 3D Viewer and tell us where you are, what you’re seeing and maybe what earthquake patterns are evidenced in your pic. Please remember to read and respond to at least one other of your classmate’s post.

Example of student responses…