What are earthquakes?
An earthquake is pretty much the shaking of the earth. A whole branch of Earth science, called seismology, is devoted to studying earthquakes. Seismologists are the scientist who study earthquakes. Most earthquakes take place near the edges of *tectonic plates which are giant pieces of Earth's thin, outermost layer. Tectonic plates move in different directions and at different speeds. (Holt Science & Technology: Earth Science pg. 224)
Deformation
Deformation is the change in the shape of rock in response to stress. Rock along a fault deforms in mainly two ways.
Plastic deformation does not lead to earthquakes when elastic deformation does. Rock can stretch farther without breaking than steel can, but rock will break at some point. (Holt Science & Technology: Earth Science pg.225)
Plastic deformation does not lead to earthquakes when elastic deformation does. Rock can stretch farther without breaking than steel can, but rock will break at some point. (Holt Science & Technology: Earth Science pg.225)
elastic rebound
Elastic rebound is the sudden return of elastically deformed rock to its original shape. It is like the return of the the broken rubber-band pieces to their unstretched shape. (Holt Science & Technology: Earth Science pg. 225)
Measuring earthquakes
Seismographs are instruments located at or near the surface of the Earth that record seismic waves. When the waves reach a seismograph, the seismograph creates a seismogram. A seismogram is a tracing of earthquake motion and is created by a seismograph. seismologist find an earthquake's start time by comparing seismograms and noting the differences in arrival times of P waves and S waves. Seismologists also use seismograms to find an earth's epicenter. The point on the Earth's surface directly above an earthquake's starting point is an epicenter. A focus is the point inside the Earth where an earthquake begins. (Holt Science & Technology: Earth Science pg. 230)
Earthquake-resistant building technology
Mass damper-a weight placed int he roof of a building.
Active tendon system- works much like the mass damper system but on the bottom on the building instead of the top.
Base isolators-act as shock absorbers during an earthquake.
Cross bases-places between floors.
Flexible pipes-help prevent waterlines and gas lines from breaking. (Holt Science & Technology: Earth Science pg.237)
Active tendon system- works much like the mass damper system but on the bottom on the building instead of the top.
Base isolators-act as shock absorbers during an earthquake.
Cross bases-places between floors.
Flexible pipes-help prevent waterlines and gas lines from breaking. (Holt Science & Technology: Earth Science pg.237)