Fault: California Coast
Fault: Istanbul Coast
Fault: Kingston Coast
Fault: Port Au Prince, Haiti
On October 11, 2010, ScienceDaily announced that Geologists from across the globe studying the Jan. 12 earthquake in Port Au Prince, Haiti had found in their research, that cities such as. Los Angeles, Kingston, and Istanbul are at a higher risk for destructive tsunami’s than ever expected. Scientists concluded this after looking at the parts of the island where the 9 ft.. high, tsunami waves had landed on shore, generated by the magnitude 7 earthquake. They also developed geological field surveys at sites on and offshore, close to the earthquakes epicenter. They found that the tsunami, which occurred there, was mainly caused by weak sediment along the shore that had slid down along the seafloor and had created the displacement of the overlying water in the ocean. The scientists gathered data from faults beneath the ocean floor and land, the vertical movement of land, underwater topography of the seafloor and the evidence of the waves created by the tsunami. The study showed that, “Combined with newly discovered evidence of historic tsunamis, the survey revealed a third of all tsunamis in the area are generated in this way.”
Haiti’s capital as well as Los Angeles, CA Kingston, Jamaica, and Istanbul, Turkey are all located on the coast and are all located near active geological features called strike-slip faults. These faults are created where two tectonic plates slide past and rub against each other. Geologists previously had thought that these faults did not have a high tsunami risk because when they rupture, they do not vertically displace the seafloor, which is how most tsunamis result. The most recent research studies, like the one discussed above, suggest that even if moderate earthquakes are present at these faults, it could in fact generate tsunamis without evening creating the vertical displacement of the ocean floor. The research showed that even if moderate earthquakes were to occur on these strike-slip faults tsunamis could be generated by means of submarine landslides.
"Organizations that issue tsunami warnings usually look for large earthquakes on thrust faults," said Hornbach. "Now we see you don't necessarily need those things. A moderate earthquake on a strike-slip fault can still be cause for alarm."
This news report goes along well with many of the things we have studied in depth in our Earth Science course. It connects many of the different geological features and occurrences that we have discussed and shows how they are connected and work together. First, plate tectonics and boundaries are the basis of this study. We learned about the evidence for the theory of plate tectonics and we have previously studied the different rock formations caused by the force of plates and the cause of earthquakes. Having knowledge in the different boundaries (convergent, divergent and transform) helped me to understand what the article was saying. This issue is also related to our course through our discussion of the difference between uniformitarian’s and catastrophism. Earthquakes, which create tsunamis, (when they occur underwater at plate boundaries) are both examples of catastrophism (violent events, that change the geological landscape of the earth). Furthermore, we recently discussed topography and this research used underwater topography to study the cause of tsunamis at these plate boundaries where there are submarine landslides. We learned how topographic maps are important tools when it comes to the study and effective interpretation of our earths land features. All of these topics regarding this news report are connected to many of the aspects of physical science we have studied.
We have previously seen the damage of tsunamis like the one in Indonesia in 2004 and we must take action and take certain steps to try and find new methods of predicting/ seeing the warning signs of tsunamis. We also must provide a better system of advanced warning to people who live near these high-risk areas. I found this current research and issue to be very frightening in many ways. To think that these strike-slip faults are on the coasts of these highly populated cities is terrifying. I believe that people need to become more aware of the high risk in tsunamis around the globe. Governments should be prepared and ready to take action if one does occur. Perhaps our government should think about putting in place a program which studies these faults, so tsunami warnings can be issued a great deal in advance. It was very helpful to have had learned the background of many of the scientific terms used in the news report, in class. I feel that there needs to be in-depth research and various studies to find out more about submarine landslides causing tsunamis, as well as studies to predict or be able to figure out where faults are that could possibly be at a high risk of tsunamis are. It does give me some relief however, that there are scientists that are dedicated to studying the causes of such great catastrophes like tsunamis and are trying to help in making the aftermath of these events less devastating on the human population by announcing that even moderate earthquakes need to be looked at and tsunami warnings need to be given far in advanced.
“With additional funding from The Society for Geophysics' Geoscientists Without Borders program, Hornbach and others are now conducting a new research project in nearby Jamaica to assess the tsunami threat there. "The geology of Kingston, Jamaica is nearly identical to Port Au Prince, Haiti," said Hornbach. "It's primed and ready to go and they need to prepare for it. The good news is they have a leg up because they're aware of the problem."
Source: University of Texas at Austin (2010, October 11). Tsunami risk higher in Los Angeles, other major cities than thought, Haiti study suggests. ScienceDaily. Retrieved October 15, 2010, from http://www.sciencedaily.com /releases/2010/10/101010133626.htm
Link To Article: http://www.sciencedaily.com/releases/2010/10/101010133626.htm
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