Earthforce is the pushing and pulling in the core, crust, or water of the Earth that causes motion like eruptions, quakes, or floods. This page provides illustrations and simple explanations of earth force.
An organized source for recent earthquake activity in the United States, organized by region.
Earthquake - University of California
A comprehensive site with lots of information about earthquakes.
Elastic Rebound Animation
Shows how earthquakes occur using a visual demonstration.
Every Place Has Its Faults!
Describes and illustrates the four basic types of geologic faults.
FEMA for Kids: Earthquakes: Learn about historic earthquakes, earthquake fact and fiction, and disaster intensity scales. See a map of states at risk of earthquakes.
How Earthquakes Work: Learn how earthquakes work, what are sliding plates and faults, how to rate the magnitude and intensity of an earthquake.
Inventors Online Museum - Who was Charles Richter?
Find out about the man who is the namesake of our modern Earthquake measurement system.
Features puzzles and a quiz about Earthquakes.
Largest Earthquakes in American History
A list (with descriptions) of the 15 largest earthquakes in American history.
Last 30 Days of Earthquake Activity
Features a map of recent earthquake activity around the world, as well as a list with descriptions of each individual quake.
On Shaking Ground
Provides information about earthquakes, as well as a list of notable tremors in history.
The Restless Planet:
Earthquakes PBS's Frontline special on plate tectonics and earthquakes.
San Francisco Museum - The 1906 Earthquake
A comprehensive source for information about the San Francisco Earthquake of 1906.
A PBS site dedicated to the technical aspects of seismic activity.
Things to Learn about Earthquakes
An all-in-one resource for earthquakes, includes technical information about the mechanics of earthquakes.
United States Seismicity
Contains a comprehensive list and maps of seismic activity in the history of the United States, organized by state.
USGS Earthquakes for Kids:
Check out the earthquake glossary, earthquake facts, and frequently asked questions about earthquakes.
Virtual Earthquake Simulations
Local Earthquake Information
Hollister and the Calaveras Fault
Photos of the creeping fault line through Hollister.
A walking tour of the Calaveras fault in Hollister, California
Lots of information, diagrams and photos illustrating the fault line through Hollister.
Plate tectonics operating over geologic time has changed the patterns of land, sea, and mountains on Earth's surface. As the basis for understanding this concept:
- Students know features of the ocean floor (magnetic patterns, age, and sea-floor topography) provide evidence of plate tectonics.
- Students know the principal structures that form at the three different kinds of plate boundaries.
- Students know how to explain the properties of rocks based on the physical and chemical conditions in which they formed, including plate tectonic processes.
- Students know why and how earthquakes occur and the scales used to measure their intensity and magnitude.
- Students know there are two kinds of volcanoes: one kind with violent eruptions producing steep slopes and the other kind with voluminous lava flows producing gentle slopes.
- * Students know the explanation for the location and properties of volcanoes that are due to hot spots and the explanation for those that are due to subduction.
Earthquakes, Volcanoes, Hot Spots, and Tsunamis