Hilltop, Batangas City
College of Engineering
“READINESS AND RESPONSE”
EARTHQUAKE AND ITS DESTRUCTIONS
In Partial Fulfillment in
English Communication 1
Andal, Arvin William C.
Arriola, Charlotte May B.
Balmes, Ivan Macdowell J.
Casas, Camille R.
Lopez, Sharlyn B.
Manalo, Christian Joseph F.
Ona,Vince Joseph M.
Pentinio, Joanne A.
Roxas, Mark Anthony B.
II. BRIEF INTRODUCTION
The earth is a dynamic, evolving system. It’s all over in a matter of second. But Earthquakes have a way of stretching time. They can make a half a minute seem like forever. And when earthquakes occur, when the ground shakes and building sway, you may think that it is the end of the world.
The earthquake, considered as the independent natural phenomenon of vibration of the ground, in very few cases poses a threat to humans, as for example when it causes major landslide or tidal wave ( tsunami). The earthquake becomes a dangerous phenomenon only when it is considered in relation with structures. Of course, the problem is the structure under seismic excitation and not the earthquake itself. This is because the structural system is designed basically for gravity loads and not for the horizontal inertia loads that are generated due to ground accelerations during an earthquake. Therefore, the earthquake has begun to become a problem or humans since they started building. Since the early steps of the technological development of mankind the joy of creation was associated with the fear that some superior force would destroy in few seconds what was built with great effort over a lifetime. In other words, the earthquake was always associated with the structure and therefore it mainly concerns the structural engineer.
Although destructive earthquakes a confined to certain geographical areas, the seismic zones, the large-scale damage that they cause in densely populated areas and the number of deaths are such that they have an impact on the whole world.
Earthquakes, because of the deaths and the damage to buildings that they cause, have several economic, social, psychological and even political effects in the areas and the countries where they take place. Thus, many scientist deal with this problem, such as seismologist, engineers, psychologists, economists and so on. All these scientific discipline are coordinated by special bodies on a nation level and by special institutes of interdisciplinary character, or at the university level, by interdepartmental cooperation. The goal of all these efforts is basically the earthquake-resistant structure, that is its improvement from the safety-cost point of view, which are two antagonistic parameters.
III. RELATED LITERATURE AND STUDIES
This chapter presents a review of related literature and other studies that have a close bearing with the present study. This provides insights and enriches variables that help the researchers to integrate the facts and knowledge that they gathered and discussed for the enrichment of the study.
Scientists at NASA's Jet Propulsion Laboratory, Pasadena, Calif., and the University of California, Los Angeles, have concluded that earthquake fault zones in California's eastern Mojave Desert are moving in different ways than they expected. For years researchers were aware that movement in the southern California shear zone was distributed over a 100-kilometer (60-mile) wide area. However, they assumed that deep below the surface the Blackwater Little Lake and the Garlock faults were creeping steadily, something that the new study seems to contradict.
New findings indicate that more than half of the right-lateral motion of the Eastern California shear zone is sharply concentrated along the Blackwater Little Lake fault system. The rapid strain accumulation observed along the fault system indicates that the fault is building up stress in the shallow...