In the same manner, the breakage of rock during an earthquake produce vibrations called seismic waves that radiate outward from the point of fracture. Provided that, the instrument used to record and measure these vibrations is called a seismograph ( EarthquakesCanada, 2013 ). About 132 A.D. , Chang Heng, a Chinese astronomer and mathematician, invented the first seismometer. ( Duncan, 2014). For the most part, seismographs are securely fixed to the surface of the Earth. ( Than, 2010). In general, a modern seismograph includes five basic pieces (Figure 2): a clock, a sensor called a seismometer,an electronic amplifier, a seismogram that traces a chart, and a data recorder that saves the information for later examination. The clock records precise arrival times of certain seismic waves. Furthermore, the seismometer measures the shaking strength at the instrument 's location and compares the motion of a support structure that shakes with the land surface to a pendulum. Finally, the recorder registers seismic signals and vibrations with a pen attached to the pendulum, and a roll of paper that moves …show more content…
Apparently, several people might assume that an earthquake proof building must be built heavy and massive. However, according to a universal structural engineering company, the structure of the building needs to be as light as possible. In order to be light, it needs to be done with profiled steel cladding together with a layer of attached insulation. In addition, it is necessary that the floors of the structure are made as light as possible. Recently, architects developed an idea of placing the buildings above their base on a chain of flexible springs and protected cylinders, in order to prevent earthquakes from knocking them from their foundation (Figure 3).In general, the most frequent kind of cylinder is the rigid lead core wrapped in alternating layers of rubber and solidified steel. The center of the core supplies vertical strength while the layers of rubber and steel material allocate horizontal resistance. These flexible but solid poles can be attached to the building with steel plates raising it away from the destructive force of the earthquake’s collision while they absorb and move with the waves and vibrations. When the earthquake crashes, the cylinders will move with it rather than the entire structure of the building, reducing the damage caused by earthquakes ( Tech21, 2014). In conclusion, the goal of earthquake-proof