All earthquakes with a magnitude over 4.0 that have occurred in the USA over the past 50 years.
Patterns of large earthquakes across the contiguous USA and northern Mexico can be seen with this map. Among the things I try to get my students to notice are:
- Way more earthquakes on the west part of the country vs the rest of the nation
- Large concentration of earthquakes along the San Andreas fault system
- Large concentration of earthquakes associated with the rifting of the Baja Peninsula
- Large concentration of earthquakes associated with the extension of the basin and range province
- Large concentration of earthquakes associated with the Sierra Nevada uplift
- Deeper earthquakes can been noticed along areas of active subduction – especially in northern California and Washington state
- Clusters of earthquakes in Oklahoma and New Mexico associated with fracking
- Earthquake activity in the New Madrid zone (Missouri) / central Mississippi valley thought to be associated with an ancient plate boundary or rift zone
- Relatively few earthquakes in Oregon (even though subduction is ongoing) should be a cause for concern = plate lockup?
KML file for Google Earth: EQs_USA_past50_4+
Example JPG of map showing entire country: USA earthquakes