An earthquake is a vibration that travels through the earth's crust. They are caused by movement of the earth's tectonic plates, volcanic eruptions, or a ridge below the ocean. Earthquakes were known as one of the greatest phenomenon for a very long time. Today there is a much better understanding of what causes them through more in depth research and with the help of technological advancements like a seismograph. With such technology, scientists are able to register the type of waves and determine where an earthquake originated from. According to the United States Geological Survey, more than three million earthquakes occur every year. They have killed these many people, due to structures failing while people are occupying them.
It is very unlikely to be able to predict where an earthquake will occur next. With technology scientists are
…show more content…
It is between the San Andreas Fault and the Hayward Fault where it meets up with Oakland. During an earthquake it allows movement of the entire bridge. This is a very critical bridge in the San Francisco as more than 250,000 thousand people pas through this bridge daily. The self-anchored suspension bridge also has a shear link beam which allows the four legs in the bridge to move independently. The shear link beam takes the energy from the earthquake. This allows the bridge spans to shift back-and-forth without them failing. The shear link itself will bend, but the remaining part of the bridge will be able to move freely without any damage. Another thing they use is a hinge pipe beam which allows the bridge to move in sections. It has a piece similar to a fuse which can be replaced after a strong earthquake occurs. The bridge is supported by piles which are angled into the ground so they have greater rigidity and allowing for more movement. They are driven into the ground several hundred feet so that they can allow the bridge anchors to