Since large fault ruptures require the build-up of a great deal of stress, many years pass between repeated surface ruptures on a single fault. The average time between such ruptures, known as the recurrence interval of that fault, is a useful measurement for assessing both the slip rate of the fault and the risk the fault presents. This activity contains three exercises. In the first, students study ... Full description.

This educational module has been designed to provide students with the opportunity to interactively investigate the nature of earthquakes. The module has been divided into three major sections, "What is an Earthquake?", "The Distribution of Earthquakes", and "Measuring Earthquakes". Each section presents background material and interactive learning activities allowing students to understand such characteristics ... Full description.

This resource explores earthquakes and seismic hazards, using the San Francisco area as an example. Materials include histories of San Francisco's earthquakes, including the 1906 'Great Earthquake' and the 1989 Loma Prieta quake. A section on quake basics addresses the relationship between earthquakes and plate tectonics, fault movements, seismic waves, and how earthquakes are measured. For educators, ... Full description.

This activity has students research a list of volcanoes and then write detailed information they researched under a column that identifies that type of volcano - Cinder Cone, Composite, or Shield. Included are a worksheet and a collection of links to referential websites about specific volcanoes. Full description.

This report reviews two methods of earthquake prediction: statistical analysis and observation of geophysical precursors of earthquakes. Statistical analysis involves observing the history of earthquake occurrences in a given region to see whether there are patterns or cycles; two case studies are provided as examples: Friuli, Italy and Parkfield, California. Five geophysical precursors, changes in ... Full description.

This report decribes research being carried out in Parkfield, California whose purpose is to better understand the physics of earthquakes: what actually happens on the fault and in the surrounding region before, during and after an earthquake. Ultimately, scientists hope to better understand the earthquake process and, if possible, to provide a scientific basis for earthquake prediction. Topics include ... Full description.

This report describes recent efforts at earthquake prediction, focusing on the modern era beginning in the mid- to late 1970's. Topics include a history of prediction efforts, the measurement of physical parameters in areas where earthquakes occur, and the development of a model upon which predictions could be based. The efforts centered around Parkfield, California, whose well-known seismic history ... Full description.

In response to the Nisqually earthquake of 2001, the Washington State Division of Geology and Earth Resources (DGER) developed two types of earthquake hazard maps for every county in the state: liquefaction susceptibility maps, which outline areas where water-saturated sandy soil loses strength during earthquake shaking, and National Earthquake Hazards Reduction Program (NEHRP) site class maps, which ... Full description.

This portal features an alphabetical listing of links to standard and three-dimensional (3D) images of geological and natural history-related subjects in the National Parks of the United States. The 3D images are anaglyphs and require red and cyan 3D viewing glasses. These full-size images may be slow to download. Users can click on a national park to start an image tour, use a subject index, location ... Full description.

This web site provides an interactive map of global seismic activity that is updated every 30 minutes. The site uses data from the National Earthquake Information Center to produce a world map with clickable areas of seismic activity. Users can click on geographical areas of the map, and will be taken to a table which describes the time, location, magnitude and comments about particular seismic events. ... Full description.