The USGS monitors and reports on earthquakes, assesses earthquake impacts and hazards, and conducts targeted research on the causes and effects of earthquakes. We undertake these activities as part of the larger National Earthquake Hazards Reduction Program (NEHRP), a four-agency partnership established by Congress.
On July 17, 1998, three huge waves – "tsunamis" – up to 15 meters high struck the north coast of Papua New Guinea, killing at least 2,200 people. A major earthquake, itself consisting of waves traveling through the Earth, triggered an underwater landslide that created the tsunamis. Radio stations reported the disaster by transmitting electromagnetic radio waves to listeners around the world. Listeners were able to hear the news transported by sound waves created by their radios.
Seismology is the study of earthquakes and seismic waves that move through and around the earth. A seismologist is a scientist who studies earthquakes and seismic waves.
Seismic waves are the waves of energy caused by the sudden breaking of rock within the earth or an explosion. They are the energy that travels through the earth and is recorded on seismographs.
Seismic activity at Yellowstone Lake in Yellowstone National Park increased in late December 2008. As of January 8, 2009, the seismic activity has markedly decreased.