Adrian Howley
Classical Argument
Reporting earthquakes are very critical to studying the behavior of tectonic plates. The very first recorded earthquake occurred in the year 1831 B.C. and is currently known today as the 526 Antioch Earthquake. The area affected was Antioch, China (located between the Syria and Turkey regions). Not much is known about how the report was formed. However, this historic report did include information about how the aftershocks lasted for twelve months. Other details from this report indicate that the death toll is around 250,000 to 300,000 casualties. Scientists today can only prove that the earthquake occurred between May 20 and May 29 (date translated from B.C. to Calendar Year). The first instrument to measure the seismic waves of earthquakes was invented by Charles F. Richter at the California Institute of Technology. (Bellis, 2013) He introduced his new instrument called the Richter scale, to the world of science. His invention allows scientists today to study the mechanics behind earthquakes and locate the epicenter to which the natural disaster originated. The largest earthquake recorded by the Richter scale was measured on May 22, 1960 at a magnitude of 9.5. The quake resulted in 1,886 deaths, 2,000,000 homeless, and $1,175,000,000 total in damages. (“The Largest Earthquake”, [PDF file]) If we want to see these large numbers slide down to zero, the impossible will need to be challenged by science. Skyscrapers are buildings consisting of many floors, usually ranging from 18 to 110 stories. Each tower is unique and all of these super structures have requirements to pass in order to continue its service for businesses. Currently, a skyscraper is required to have vibration dampers and mass or wave dampers. First, a skyscraper is categorized by its height and how much area is covered total. There is no ‘official’ number indicating the number of stories a tower must have. A skyscraper can reach a height of 300 feet with only two floors: elevators connecting the top floor to the bottom floor. Second, there are height limits for structures with different materials. Now that you (already) know what a skyscraper is, I will continue to the one important safety feature of these mega structures. When a tower begins the building phase, the first step is to dig a foundation that will house the vibration and mass damper. Without these two critical devices, the building will most likely collapse under a 5.0 magnitude earthquake. To get an idea of what an earthquake feels like, I will explain four different magnitudes including the ground effect of each. A 3.0 magnitude earthquake may feel like a large semi rolling by. The vibrations will be faint but not strong enough to tip anything. A 5.0 magnitude earthquake would cause the floor beneath your feet to suddenly ‘stutter’ in small increments. A 6.0-7.0 magnitude earthquake will feel very similar to a bus. For example, as you stand in a crowded public bus or subway, your only support keeping you upright is your two feet. The sudden ‘jerk’ followed by several ‘sways’ as the subway begins to leave is very similar to a magnitude at that level. Anything higher than the levels I have pointed out would probably give you the sensation that you are standing on a treadmill, except the treadmill only moves back and forth. The shock absorbers installed under tall buildings help prevents the base of the building from moving at the same speed as the ground’s movement. Overall, science is making great progress towards surviving a deadly disaster. If we knew exactly when an earthquake would strike and its magnitude it would produce, structures would have only temporary dampers that could easily be removed after the earthquake has exhausted itself. One last thing I want to point out. When it comes to safety, preparation comes first. Always have a backup survival kit incase a natural disaster targets your area. ("Are you prepared?," 2013) Unfortunately, earthquakes are unpredictable and can leave populated towns and cities to heal by themselves. Millions of dollars in recovery fees will only make matters worse. If you think that the initial shake is the worst, think again. Aftershocks can be just as deadly, unpredictable, and, in some cases, more powerful than the main strike. Rarely, a town would be lucky to be introduced with a 5.0 magnitude earthquake, allowing enough evacuation time before the main quake occurs. Do not assume that a small earthquake that everyone can feel will be temporary. An aftershock is most likely already on its way to make its point to how powerful Mother Nature can be.
References:
Bellis, M. (2013). Charles richter developed the richter scale - neis interview. Charles Richter - The Richter
Magnitude Scale, doi: http://inventors.about.com/
(2012). 526 antioch earthquake. Casualty by Natural, doi: http://www.armageddononline.org/disaster/
Casualty-by-Natural/
(1960, May 22). The Largest Earthquake in the World "[PDF file]"
[Web Graphic]. Retrieved from http://earthquake.usgs.gov/ earthquakes/world/events/1960_05_22_seismogram.php Tuned mass dampers & absorbers. (n.d.). Retrieved from http://www.csaengineering.com/products-services/ tuned-mass-dampers-absorbers/
Barss, K. (2007). The history of skyscrapers; a race to the top.
InfoPlease, doi: http://www.infoplease.com/
Tuned mass damper systems. (2002). (Master's thesis, Purdue
OWL)Retrieved from https://engineering.purdue.edu/~ce573
/Documents/Intro to Structural Motion Control_Chapter4.pdf
(2013). Are you prepared?. Build a Kit, doi: http://72hours.org/