Gifts for a 25th Anniversary. 25th anniversary gifts should express your love and adoration in a simply elegant fashion. The 25th wedding anniversary is commemorated traditionally with gifts of silver, and we have a variety of options that make for a perfect silver wedding anniversary gift. Peruse silver lockets, delightful champagne glasses, commitment bands, and more for a gift that perfectly presents the 25-year anniversary motif.
The released energy travels as shock waves, called seismic waves, which may be felt and measured. The study of seismic waves is known as seismology, a word derived from a Greek word meaning to shake.. Seismographs are the instruments which record earthquakes. Scientists use these instruments as their principal tool to study seismic waves. They are very sensitive instruments that can detect, measure and record ground vibrations and their intensities during an earthquake.
The aftermath of an earthquake, Golcuk, Western Turkey. The power of an earthquake is measured using a seismometer. A seismometer detects the vibrations caused by an earthquake. It plots these vibrations on a seismograph. The strength, or magnitude, of an earthquake is measured using the Richter scale. The Richter scale is numbered 0-10. 1  Earthquakes measuring just one or two on the scale are very common and can happen everyday in places like San Francisco. 2  These earthquakes are so small that people cannot feel them, they can only be picked up by a seismometer.