Overview
1. Recall that the earthquake that many of us felt just a few weeks ago was a magnitude 4.5. Also, remember that every time the magnitude increases by 1, the amount of energy released is 32 times greater. With that in mind, how much more energy was released by the largest earthquake ever recorded than by the earthquake that shook L.A. a few weeks ago?
Looking at the locations of the 20 largest earthquakes of all time (by clicking the link that shows them plotted on a map), you can see that they have occurred in different places around the world. What is similar about the plate boundaries in all of these locations? The plate tectonic map below may help you answer.
[Image unavailable: plateboundaries.jpg]
2. Does the San Andreas fault (our local plate boundary in the L.A. area) have the potential to have an even bigger earthquake than the current largest one ever recorded? Why or why not?
Now let's look at a map showing all earthquakes of magnitude 7 or higher in the United States:
https://earthquake.usgs.gov/earthquakes/map/?extent=-85.2298,-407.46094&extent=85.2298,155.03906&range=search&listOnlyShown=true&baseLayer=terrain&timeZone=utc&search=%7B%22name%22:%22Search%20Results%22,%22params%22:%7B%22starttime%22:%221900-01-01%2000:00:00%22,%22maxlatitude%22:72.299,%22minlatitude%22:18.01,%22maxlongitude%22:-66.973,%22minlongitude%22:-195.645,%22minmagnitude%22:7,%22orderby%22:%22time%22%7D%7D (Links to an external site.)
3. Note that there are no earthquakes of magnitude 7 or higher recorded anywhere in the eastern half of the continental United States. Why is this?
4. List a few places along the coast of L.A./southern California that could be flooded by a tsunami. (2-1)
5. List a few places that are just as close to the coast as your answers to 2-1, but that are not thought to be at risk of flooding from a tsunami.
6.Why do you think the places you listed in question 1 more at risk of tsunami flooding than the places you listed in question 2?