Wednesday, January 15, 2020

Environmental Geology Essay

In 2006, seismic researchers can predict the location and direction of earthquakes by merely 10 to 20 minutes before it happens. Researchers use ultrasounds to assess earthquakes faster. Precise ultrasound images were recorded from the fault which is ruptured and the direction the rupture goes (American Institute of Physics [AIP], 2006). In 2008, seismic researchers can now predict earthquakes with much more preciseness and earlier than other previous equipments. A researcher from Rice University named Fenglin Nui and some of his colleagues are currently working on some experiments that can detect earthquake in a much earlier time. The method they use is detecting P-waves with the use of some super sensitive instrument called the Seismic Stress Meter. P-waves are the fastest of all the waves associated with earthquakes (Rice University, 2008). 2. (20 pts) What are the lessons learned from the 2008 Sichuan earthquake in China? What are the lessons learned from the 1985 Mexican earthquake? Discuss. The destructive earthquake that hit Sichuan region in China brought lessons that seismic researchers deem helpful in predicting earthquakes. Sichuan region is located in highly mountainous area that is active and could be attributed to the earthquake hazard that happened. Topographic analysis can now help scientists to assess area that has high risks of having earthquakes (Pennsylvania State University, 2008). The destructive earthquakes in Mexico City made a realization for a civil engineers association. They all realized that their building codes where buildings are designed to be built still are of no level with the earthquake intensities in Mexico. A problem arises when the soft clay layer of the ground was struck by the earthquake. The soft clay layer of ground started to transmit more movements higher than what engineers have expected. The ground shook buildings in Mexico much longer than what is expected (Peterson, 1986). 3. (15 pts) Discuss the 2008/2009 Chaiten volcanic eruptions in Chile. What are the implications of this natural disaster on the local residents? Chaiten volcanic eruption was one that local residents never expected to happen. The Chaiten volcano was said to be dormant for almost 10,000 years now. But surprisingly and unexpectedly, the volcano has shown activity and after a few days it erupted. Many residents were evacuated from near the volcano. About 4000 people within 6 mile radius from southern region of Chile were evacuated. The town near the volcano was almost buried in ashes just like what happened to Pompeii when Mount Vesuvius erupted. The sudden eruption after a long sleep gave residents fear of the volcano erupting again at any given time (University of Colorado, 2008). 4. (15 pts) Explain two different measures that can be taken to prevent, or at least minimize, the occurrence of landslides. One of the most effective measures that can be taken to prevent occurrences of landslides is through afforestation. Trees can greatly contribute to minimizing numbers of landslides in many ways. Trees can help absorb water from the soil. Water is said to be one of the main cause of landslides. Another is that trees can hold the soil firmly in the ground also minimizing the landslide occurrences. Another measure that can be used to prevent landslides is by creating levees or dykes. In this method, landslides are prevented by building walls usually near rivers which regulates water levels that cause the landslides (People’s Daily Online, 2000). 5. (10 pts) What is the mechanical paradox implied by long runout landslides? Heavy rain is said to have started landslides. So, one might think that landslides move and accelerate together with water. The long runout landslides are really caused by heavy rains but there is really no water associated with the movement and acceleration of landslides. The movement and acceleration of landslides are associated with the pressure vibrations called the acoustic fluidization. As the land slides pressure vibrations were generated making a frictionless effect to the ground which causes the land mass to move like a fluid (Collins and Melosh, 2007). References American Institute of Physics. (2006, April 1) Real-Time Quake Detection:Seismologists Use Ultrasounds to Assess Quakes Faster. ScienceDaily. Retrieved March 27, 2009 from http://www. sciencedaily. com/videos/2006/0406-realtime_quake_detection. htm Collins, G. and Melosh, H. (2007, July 15). Acoustic Fluidization and the Extraordinary Mobility of Sturzstroms. Retrieved March 27, 2009 from http://amcg. ese. ic. ac. uk/~gareth/publications/abstracts/lpsc03b. pdf Pennsylvania State University. (2008, July 24). Chinese Earthquake Provides Lessons For Future. ScienceDaily. Retrieved March 27, 2009, from http://www. sciencedaily. com ¬

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