This resource provides information about the science, phenomenon, and effects of tornadoes. Video clips include an outing with a tornado hunter, an interview with a tornado survivor, and an animation depicting the science of tornado formation. Full description.

This table presents the modified Mercalli Intensity Scale (MMI), a measure of earthquake intensity based on shaking severity and observed effects of earthquakes. It includes MMI value, a description of shaking severity, and a summary and full description of damage effects. Each MMI value is accompanied by an illustration showing its expected effects. Full description.

This table provides information on all earthquakes in the California-Nevada area, as shown on the U.S. Geological Survey's real-time earthquake map. The table consists of all earthquakes cataloged in the last week (168 hours). The top three magnitude categories above magnitude 3 are in highlighted in red. Information provided includes magnitude, date and time, latitude and longitude, depth, and location. ... Full description.

This interactive map shows the locations of all earthquakes in the California-Nevada area for the past week. The map is subdivided into 2x2 degree sheets that can be accessed by clicking on the desired area. Locations of major fault systems are shown, and earthquake locations are color-coded to indicate whether they occurred in the past hour, day, or week. The magnitude of each earthquake is keyed ... Full description.

This magazine article describes how two high-magnitude earthquakes (7.6 in both instances) triggered landslides in El Salvador and Taiwan which caused extensive damage and loss of life, apart from the shaking of the earthquakes themselves. The article points out that the two areas have common features- tectonically very active, high steep slopes and deeply weathered material, that made the landslides ... Full description.

This collection of video clips from the Caltech Woodframe Project shows what happens to a wood-frame house when it is shaken in the laboratory under conditions resembling those of an earthquake. There are both interior and exterior views, and also tests with furnishings in the house. The videos are available in two formats. There are also links to a description of the project, objectives of the testing, ... Full description.

This news article describes how mountain lakes in Nepal and Bhutan have become so overfilled by water from melting glaciers that they are in danger of overflowing. Scientists from the United Nations Environment Program (UNEP), along with remote-sensing experts from the International Center for Integrated Mountain Development (ICIMOD), predict that in the next half decade or so, the Himalayas could ... Full description.

This set of maps provides information on earthquakes for the United States and the world. The maps are divided into regions for ease of selection. Earthquake data are reported for the last seven days and include locations, magnitudes (denoted by the size of the symbol), and time (denoted by the color of the symbol). Full description.

The glossary has about 60 terms that are primarily types of volcanoes or vents, eruption types, and eruptive products. Clicking on a term displays a captioned photograph illustrating the concept and a glossary definition. Below the photgraph are related glossary terms and sometimes other information or photograph links. 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.