Hobbies And Interests
Recording Earthquakes
Seismographs are used, first and foremost, as a tool for recording earthquakes. Scientists use the seismographic data to determine intensity, origin time, depth and location of quakes. A network of seismometers around the world fixes the location of an earthquake by measuring the differences in how long the tremors took to get to each station. Using mathematical formulas, scientists are able to effectively calculate the desired information.
Mitigating Hazards
Predicting earthquakes in the short term is difficult to do with any degree of accuracy. Some seismologists doubt it can be done at all. However, seismographs are useful for making statistical estimates over a much longer time frame -- along the order of 30 to 100 years. This allows for areas to prepare for eventual earthquakes. Seismographic data is also useful for predicting tsunamis following earthquakes. Knowing the location and severity of a quake is helpful in coordinating relief efforts.
Detecting Explosions
Seismology is a useful tool in monitoring compliance with the Comprehensive Test Ban Treaty, which bans testing of nuclear devices. Nuclear tests are generally conducted underground and, like earthquakes, produce seismic waves. Nuclear waves, however, are generally distinguishable from those of natural occurrences, although errors in interpretation have occurred. Seismographs may also be useful in determining the yield, or size, of a nuclear device that is detonated.
Exploring for Oil
Scientists often use seismographs to find oil and other natural resources. The process is called seismic reflection and employs portable seismographs to measure the reflection of sound waves through various geological formations. The process originally used a man-made explosion to create the waves, but current technology involves a machine generating elastic shock waves. The resulting data informs the scientist about the underlying structure based on the time it takes the waves to reach the seismograph.