In this activity, students examine a seismogram display called a seismic record section in which each trace is a seismogram recorded at a specific seismograph station. The seismograms are plotted according to the distance (in degrees, geocentric angle) from the earthquake location and time from the earthquake origin. The traces are of the vertical component of ground motion, and have been filtered ... Full description.

In this activity, students construct a model that will allow them to experiment with thermal convection, illustrating how thermal energy can generate a flowing motion in a fluid. The thermal convection in this model is similar to the convection that is inferred for the Earth's mantle and can produce horizontal flow that can cause or is related to plate motions. Students will investigate the viscosity ... Full description.

Users can access the array of seismometers operated by the the University of California at Berkeley's Seismological Laboratory in northern and central California. The Berkeley Digital Seismic Network is an array of high-dynamic range, broadband seismometers. Data from these instruments are transmitted continuously to UC Berkeley for processing and analysis. Using the interface, visitors may create ... Full description.

This radio broadcast explains how the North Pole is constantly moving due to the rotation of the Earth, which in turn is determined by any changes in the mass distribution of the Earth. The clip is 2 minutes in length. Full description.

In this activity students plot the latitude and longitude involved in the movement of the Magnetic North Pole over a period of time, predict its location by the year 2000, and justify their reasoning. Students will discover that the Magnetic North Pole has been charted over the past several hundred years and that the pole shifts an average of 15 kilometers/year. They will also learn tha navigation ... Full description.

In this activity students learn about Earth's magnetic reversals by reading two fiction stories and a scientific summary of past reversals, including graphical information. This will help students discriminate between factual and fictional descriptions of a natural phenomenon, which has been scientifically studied from the fossil and geologic record of Earth, and found to be a lot less frightening ... Full description.

The Earth hums, emitting a tone too low for human ears to detect. Geophysicists have finally located the source of the noise. As this radio broadcast reports, it comes from the largest oceans during winter, apparently the result of powerful winter storms. The hum comes from the surface of the Earth rising and falling less than a millionth of a meter, vibrating once per 300 seconds. The clip is 3 minutes ... Full description.

This is the homepage of the Marine Seismic Data Center (MSDC) of the University of Texas Institute for Geophysics (UTIG). MSDC's purpose is to organize seismic reflection and refraction data into a modern relational database management system accessible through the Internet. The web site provides access to metadata, SEG-Y (seismic shot record conversion) files, navigation files, seismic profile images, ... Full description.

This set of animations, accompanied by an audio narrative, shows the four types of wave motion seen in an earthquake: P waves, S waves, Love waves, and Rayleigh waves. A brief written narrative and a set of study questions are also included. Full description.

This tutorial provides information on the four types of wave motion seen in earthquakes (S, P, Love, and Rayleigh waves). A table accompanied by text describes their particle motion, typical veolcity, and other characteristics. The four animations show a rectangular block of material with outlined with grid lines and a filled-in grid square to highlight the particle motion and direction of propagation. ... Full description.