Information and records presented in this paper is describing the seismic hazard maps. Ground condition effect for the earthquake, and buildings react due to shaking will also be shown in this journal. It is significance for engineer to predict the damage of earthquake, and engineers also improve the techniques and theories to make structures safer.
KEYWORDS: seismic hazard map; earthquake; collapse; building; damage; seismic wave
Introduction
The continental drift theory and plate tectonics theory was first put forward by the German geologist and meteorologist Alfred Wegener at the beginning of the 20th century. He proposed that there was a single continental in 200 million years ago, and the Earth’s crust slowly separate to pieces by the
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Seismic hazards describe the expected events for dangerous due to earthquakes which is totally different with seismic risk. Seismic Risk is the losses of life and property because of earthquake (Zhenming Wang, 2009). Seismic hazard map is confirming the relative movement of various regions as on a city, province or country basis. It is significance for engineers to analyze seismic hazards by seismic hazard maps, especially for design an engineering structure. There are four procedures when identify deterministic hazard analysis (DSHA): 1. Reorganization all sources; 2. Choice of source; 3. Choice of “controlling earthquake” (fixed distance and magnitude); 4. Identify of hazard by controlling earthquake. (DOF, …show more content…
With the effort of geologists over the years, there is more quantitative method to determine magnitude of an earthquake by peak ground velocity (PGV) and peak ground acceleration (PGA) and other factors. For instance, the Richter magnitude scale is a quantified scale developed by energy release during an earthquake (Robert, 2012). It is also very important to engineers to identify earthquake motion by ground displacement, velocity and acceleration, although it is very complex, it is very useful to design
Problem Statement: Earthquakes are a natual part of the environment. They do,however,cause devistating effect on the environment. Since Earthquakes can not be avoided, maybe there is a way to determine when they are going to occur so precautions can be taken to get people to safety and protect as much of
The topics of conversation within this transcript jumped from Kiona’s vacation (seen in lines 2 to 25), to Florida and California’s water issues (seen in line 27 to 28), back to Kiona’s vacation (seen in line 29 to 32) and finished off with the San Andreas Fault/Earthquakes (seen in line 32 to 56). The initial topic of conversation was suggested by Corina (seen in line 2) in order to get the conversation started. There was no topic dropped due to embarrassment, however; there was a moment mentioned before in this analysis in which we went back to a topic. Most because at the time and based on facial expressions the participant Barbi, she wasn’t paying attention to the conversation that was happening right next to her. There also was no topic
The initial ideas of the continental drift hypothesis led to the development of plate tectonic theory. In order for the theory to be accepted, the whole scientific concept had to undergo the extensive process of scientific method. This involves an initial Observation leading to a hypothesis, attempting to explain the occurring observation. In order for this to be determined, predictions are made to explain the specific hypotheses, which are then backed up by evidence, finally leading to having a generally accepted theory. In this essay, the process in which the individual parts of the scientific method were used in the context of the continental drift hypothesis and theory of plate tectonics will be outlined whilst showing how contemporaries react negatively to incomplete scientific method.
Due to the hazard that earthquakes cause, a hazard consultant becomes a critical part of
Forty-eight years ago, Dan McKenzie graced us with his first paper on the “viscosity of the lower mantle”, or better known as the theory of plate tectonics. This theory states that the Earth is broken up in to plates that move in all different directions and speeds. The movement is caused by convection in the asthenosphere. The lower and hotter magma rises to the top and pushes the plates outwards, then cools and sinks. Also, in places like the Mid-Ocean Ridge, there are breaks in the Earth’s crust where magma comes up and replaces old rocks pushing them to either side. (Richardson) This theory is supported by irrefutable facts. Some of which are: the shapes of many of the continents look as though they at one time were all connected, there are similar fossils on almost all of the continents, and the oldest parts of oceanic plates are only around 200 million years old. This theory is as close to fact as it gets.
there were many specific scientists that contributed to this idea of the moving continents, some more than others. 2 major contributors to the idea were Alfred Wegener, and Henry Hess. They all contributed to the idea of why the plates are in different place that when the Earth was first born. One of the Scientists, Alfred Wegener, is very well known and his name is related when talking about Plate tectonics. When he first proposed( put out there) his theory ( which later turned out to be right) it was rejected immensely because he did not know how or why the continents moved.
The hypothesis explained the magnetic striping on the seafloor. Hess’ theory later supported Alfred Wegener’s theory of continental drift. The idea of seafloor spreading started when Hess was traveling, he would leave sound equipment on that took measurements of the sea floor. It appeared that there were mountains with flattened tops. He called these guyots. He believed that these were once volcanic mountains. His idea explained that hot magma would rise through the mantle and when the magma cooled, it would push tectonic plates
Author Holmes was brought into the science community by his interests in physics and geology .Author Holmes got a job as a prospecting job in Mozambique when he was 21 years old. Author soon became a scientist in rock study and proposed that convection occurred in the mantle. in 1919 Holmes suggested the mechanism: that the continents are carried by the flow of the mantle on which they sit, and the mantle is flowing because it is convecting. Author Holmes didn’t use a lot of modern technology since he first studied rock dating over 100 years ago.
The concept of dynamic considerations of buildings is one which sometimes generates unease and uncertainty within the designer. Although this is understandable, and a common characteristic of any new challenge, it is usually misplaced. Effective earthquake design methodologies can be, and usually are, easily simplified without detracting from the effectiveness of the design. Indeed the high level of uncertainty relating to the ground motion generated by earthquakes seldom justifies the often used complex analysis techniques nor the high level of design sophistication often employed. A good earthquake engineering design is one where the designer takes control of the building by dictating how the building is to respond. This can be achieved by selection of the preferred response mode, selecting zones where inelastic deformations are acceptable and suppressing the development of undesirable response modes which could lead to building collapse.
Convergent boundaries, divergent boundaries and convection currents all examples of physical evidence that supports the theory of plate tectonics. Continental drift is the theory contrived by Alfred Wegener in 1912 that states that Earth’s tectonic plates are in slow constant movement. At the time he didn’t know how the continents moved. The theory was soon modernized in the 50’s and the theory of plate tectonics became was born. Plate tectonics is the theory that tectonic plates are in slow constant movement due to convection currents in the mantle. Now we know for sure, thanks to scientific studies of convergent boundaries, divergent boundaries, and convection currents in the Earth’s mantle, that the continental drift and plate tectonics theories are not
The word tectonic plate comes from the Greek meaning "pertaining to building". This theory tries to explain the movements of the earths lithosphere ever since the past all the way up to now. Essentially, there are three main driving forces for the movement of the Earth's tectonic plates. They are mantle convection, gravity, and the Earth's rotation. Mantle convection is very similar to the theory developed by Holmes in 1929. There are large convection currents of molten material in the Earth's upper mantle. As these currents transmit energy to the Earth's asthenosphere new lithospheric material is pushed up toward the Earth's crust. Gravity is a secondary driving force for the movement of the Earth's tectonic plates. At mid-ocean ridges the elevation is higher than the surrounding ocean floor. As the currents within the Earth cause new lithospheric material to rise and spread away from the ridge, gravity causes the older material to sink toward the ocean floor and aid in the movement of the plates. The Earth's rotation is the final mechanism for the movement of the Earth's plates but it is minor in comparison to mantle convection and gravity.
Authorities have attempted to implement codes or regulations, but that has proved to be very difficult tasks becasue there are many variables that effect the dynamic response of buildings. One way to try to avoid disaster is to evaluate seismic risk is to look at a buildings hazards, exposure, vulnerability, and location. Hazards are, for example, landslides ad soil type. Exposure is a building's occupancy and function. Vulnerability is the expected performance of a building's system, and location is how often earthquakes occur in the area. (Lagorio)
Earthquakes belong to the class of most disastrous natural hazards. They result in unexpected and tremendous earth movements. These movements results from dissemination of an enormous amount of intense energy in form of seismic waves which are detected by use of seismograms. The impact of earthquakes leaves behind several landmarks including: destruction of property, extensive disruption of services like sewer and water lines, loss of life, and causes instability in both economic and social components of the affected nation (Webcache 2).
In comparison, earthquakes are measured either with a Richter scale or seismometers (Choy, George L.; Sipkin, Stuart A.; Spence, William). Seismometers are deeply placed in the ground, to catch seismic waves that in return cause zig-zag waves on the measuring tool showing how strong these waves are (Chambers, Catherine/ Choy, George L.; Sipkin, Stuart A.; Spence, William). To be able to achieve this, the seismometer has to be very sensitive so that it feels every movement and can finally graph it on paper that is printed out of a machine (Chambers, Catherine). The Richter scale measures the magnitude, energy, intensity, depth, fault geometry, and seismic moment (Choy, George L.; Sipkin, Stuart A.; Spence, William). Hurricanes are measured by categories from 1 to 5 (National Geographic Staff).
A hazard is defined as an activity or object that has the potential to cause harm if contact is made with the person, object or activity (MHS, 1996; Harmse, 2007; HSE, 2006). These hazards in a work place need to be identified and dealt with accordingly to prevent any harm to employees or any individual acquainted to a certain activity or establishment. The key roles and principles of occupational hygiene are Anticipation, Identification, Evaluation and Control (Schoeman and van den Heever, 2014; Harmse, 2008; SAMTRAC, 2012). To practise in accordance to the above principle; a hazard identification and risk assessment needs to be conducted. Anticipation is the foreseeing of the activity