The Occurrences of the San Francisco Earthquake - Research Paper Example

The Occurrences of the San Francisco Earthquake Abstract This research examines the 1906 San Francisco earthquake in the United States of America. Since the San Francisco lies in a destructive seismic zone and earthquake prone area, it must have a new way of adapting to natural and artificial earthquake cause. San Francisco experiences a possible reoccurrence of potential earthquake destructive activities that needs significant and sustainable mitigation and disaster preparedness in creating an awareness of the occurrences, causes, and their effects. The adoption of the earthquake disaster sustainable preparedness and safety should align with the modern earthquake disaster preparedness and mitigation process goals and objectives (Sucuoğlu & Akkar, 2014). The rationale of this research is to uncover the occurrence, causes and effects of the earthquakes as well as the earthquake disaster and preparedness process to reduce the incidents, causes and effects of the earthquakes disasters. Conversely, the research utilizes primary and secondary data collection methods to examine the levels of the earthquake events, causes and effects in general and specifically in 1906 in San Francisco. In this regard, it was essential to exploit all the existing literature in relation to the earthquake disasters examining the current or new evidence that was subjectively be used to provide a reliable and valid information answering the research question. The research results or findings were then used providing a generalized conclusion after analyzing the occurrence, causes and the effects of the earthquakes (Parsons & Stein, 2014). Introduction San Francisco lies on the Pacific Ocean margin characterized by occurrences of devastating and subduction tectonic earthquakes zone compared to the Atlantic Ocean margins that have consistently open and quite earthquakes since the Jurassic times. Therefore, San Francisco earthquakes within the Pacific Ocean require a high consciousness, preparedness and mitigation process for the occurrences of the earthquake compared to other earthquake seismic zones or earthquake prone areas. Earthquakes have been reported in Caribbean countries such as Haiti, Indonesia, Japan, China and North America and the west coast of Chile. However, San Francisco has been experiencing a series of earthquakes since 1906 with the most recent being in 1989 and 2014 (Parsons & Stein, 2014). Although earthquake occurrences and causes concentrate mainly in areas close to tectonic plates boundaries of the earth’s crust, unusual activities away from the seismic focus can significantly cause a greater disaster. However, the primary cause of destruction and injury during and after an earthquake disaster is an elastic vibration of the tectonic plates rather than a fault displacement. In reference to the San Francisco earthquake, the vibration, great rupture length, the horizontal displacement and the surrounding crust strain was dependent on the distance from the earthquake seismic focus and the size or the magnitude of the earthquake (Komar & Ruggiero, 2011). Fig1. Illustrating San Francisco earthquake occurrences The occurrences of the San Francisco earthquake Occurrences of the earth are series of earthquake events that illustrates the time, frequency and location in conjunction with the severity, history and the mechanisms of the earthquake events. In reference to the San Francisco earthquake occurrences, the San Francisco earthquake occurred as a strike-slip striking the coast of the Northern California resulting from the reshaping of the earth associated with tectonic plate’s movements along the Pacific Rim. There is a sequential frequency of the earthquake in the San Francisco which lies along the Pacific Rim that accounts for approximately 90% of the total world’s earthquakes (Eberhard & Wiemer, 2012). In this regard, at the great subduction zone, the San Francisco earthquake occurred when the Pacific tectonic plates constituting the surface of the earth collides with the surface of the earth. One plate subducts beneath another and gets reabsorbed into the mantle resulting to a fault rupture causing tensions and immediate subduction leading to the formation of seismic wave. The earthquake occurred at %.12 am GMT April 18th, 1906 with a magnitude of 7.8 7.8Mw maximum intensity of IX with a depth of 8km. the epicenter of the San Francisco earthquake covered between 37.75N 122.55 W (Cox & Geological Society of America, 2012). The earthquake shock waves were felt throughout the San Francisco Bay area from Oregon, Inland to Los Angeles and central Nevada lasting for about 42 seconds with the mainshock preceded by a strong foreshock by 20 to 25 seconds. Vertical displacement of the ocean water caused the occurrences of the Tsunami that further expanded the water away from the earthquake occurrence site. The San Francisco earthquake severity as a measure of the registered intensity and magnitude was devastating as the local soil condition of San Francisco to could not withstand ground shaking of 8.25 registered Richter scale (Cox & Geological Society of America, 2012). The resultant effects caused loss of over 3000 lives, loss of property and further destruction were the ignitions of fires, landslides, loss of life and destruction of homes and property. The San Francisco earthquake prediction general fruitfulness has not yet been achieved; useful mitigation planning to reduce the causes, occurrences and effects is underway for creating awareness and simple precaution controls. Mechanisms of earthquake events Fig2. Illustrating San Francisco earthquake mechanisms A sudden tectonic plate’s movement of the earth deep beneath the San Francisco Bay zones causes the origin of the earthquake along the faults. The rock fracturing within the preexisting lines of weakness causes a sudden release of the previously stored elastic energy before subduction resulting in a progressive development of seismic waves. The developed seismic waves then radiate outwards and spread around the faults causing a destructive effect on the ground services that feel the impacts of severity. However, different earth materials or local soils respond different according to the soil strength to withstand seismic shakings as geomorphologic and geographical conditions respond to seismic shaking differently inducing local seismic wave amplification (Eberhard & Wiemer, 2012). Alternatively, the massive energy developed beneath the earth surface escaped through cracks alongside other volcanic events causing glides, slides and movements of tectonic plates resulting in huge tensions within the tectonic plates. Progressively, significant shockwave tensions lead to massive pressure along the fault lines forcing the faults to give room for the tectonic plates to move over or against each other forming development of seismic waves. The seismic waves radiates in all directions outwards from the preexisting zones or lines of weakness causing shaking effects as they move to the surface of the earth resulting in earthquake severity and destruction of materials on the surface of the earth (Eberhard & Wiemer, 2012). Causes of San Francisco Earthquake Earthquakes are generally caused by natural and human activities. Natural cause’s earthquakes are volcanic eruptions, explosions, landslides, and rockfalls. However, human-associated earthquakes results due to direct or indirect human activities such mining and fluids injection into wells provoke tensionally or compression movements and vibrations along the fault lines of the earth crusts. Nevertheless, earthquakes occur specifically according to the associated lithospheric plates and the kind of the movements or fragments involved. San Francisco earth happens as a result of the interaction of tectonic plates that converge at convergent boundaries that is also known as destructive boundaries. San Francisco earthquake occurs at it always happens when tectonic plates collide and slide against each other. In San Francisco, there are two tectonic plates, the North American plate, and the Pacific plate (Parsons & Stein, 2014). The North American tectonic plate consist of the most parts of the North American continent and some parts of the Atlantic floor while the Pacific tectonic plates comprises of the great California Coastline and the majority parts of the Pacific Ocean floor. The San Andreas Fault is the primary or central boundary that separates the two plates more than 650 miles long as well as extending at least 10 miles deep. Along this earthquake area, there are other minor or smaller faults branches that connect to the San Andreas Fault Hayward and the San Jacinto from North California and South California respectively. The Pacific Tectonic Plate grinds towards the northwest sliding over the North American Plate at a frequency of approximately two inches every year (Komar & Ruggiero, 2011). The grinding causes the development of tension building up pressure on the San Andreas faults in all directions causing the development of seismic waves. The seismic waves then spread along the fault lines to the surface of the subduction zone within the San Francisco Bay area’s resulting in an earthquake. Nevertheless, parts of the subduction zones within parts of the San Andreas Fault Systems intends to adapt to the movements or tensions by a constant respond or creep forming multiple tiny shocks waves with corresponding moderate tremors. However, in subduction zones or areas where the adapted creep is consistently shifting or lacks a static value, pressure or tension accumulates for many years causing an explosive or greater earthquake if finally it occurs (Parsons & Stein, 2014). Earthquake Impacts The consequences or effects of the earthquakes occurred when the seismic waves formed continuously spread and manage to move through the earth surface causing significant effects that are capable of causing destructive effects. Earthquakes are first felt as a swaying motion followed by a slight pause of motion and finally an intense jerking shaking lasting at a specific second. For example, San Francisco earthquakes were felt for 15 seconds with a magnitude of 8.3 in 1906. Generally, the earthquake energy released at a particular area produces a collateral damage at that area. However, the effects or the impacts produced by the earthquake are classified to as either primary or secondary earthquake effects (Sucuoğlu & Akkar, 2014). Primary impacts or effects are the immediate or short-term effects that are caused by the earthquake while secondary effects are long-term effects that are evidenced by the occurrence of the earthquake at a particular geographical location. Similarly, the earthquake can be classified as according to its impacts on social, economic and environmental factors accompanied by the type of effect evidenced as either immediate or long-term collateral impacts. In reference to San Francisco earthquake in 1906, there were both secondary and primary destructive effects of the earthquake that affected the social, economic and the social aspects of all human life (Komar & Ruggiero, 2011). Fig3. Illustrating San Francisco earthquake outbreaks of fire San Francisco Primary earthquake effects The San Francisco primary or short-term impacts as a surface seismogenic expression had a greater impacts on the social, economic and environment aspects. The short-term or primary impacts, the immediate earthquake effects results to the destruction of buildings structure such as houses, bridges and infrastructure and social problems affecting human and animals existence. In reference to San Francisco earthquake primary effect, the earthquake environmental effects that occurred in the San Francisco Natural environment are several. For example, there were ground rupture and faulting across all the San Francisco Bay area’s from Salton Sea to the Cape Mendocino. All the manmade structures build adjacent to the subduction zones, and San Andrea’s faults collapsed from San Jose to Santa Rosa (Eberhard & Wiemer, 2012). Conversely, the ground shaking resulting from seismic waves triggered ground subsidence and landslides, avalanches and rock slides that made the further destruction of property and human life to approximately 3000 people. Deaths and injuries were experienced leaving more than 300000 people homeless while others were evacuated to other areas such as Berkeley and Oakland. The occurrences of ground shaking caused tectonic uplifts and soil liquefaction resulting in the intensive destruction of manmade structures and living things (Parsons & Stein, 2014). For example, in San Francisco 1906 earthquake, there was the destruction of manmade structures as the great Freeway Bridge and Beaches. There was an outbreak of fires in San Francisco associated with broken gasses line and electrical lines which caused 90% of destruction also attributed to inadequate water for extinguishing fire four for times. The seismic that occurred across the ocean floor or coastlines caused huge seismic waves up to 100 feet in height through the water resulting to the Tsunamis, which then resulted in floods in the coastal San Francisco Bay areas (Komar & Ruggiero, 2011). Fig 4. Illustrating San Francisco earthquake impacts The primary social impacts that were associated with the San Francisco earthquake are almost similar to environmental factors most were those that were associated with complications of human social life. There were multiple injuries and deaths that caused human short-term human suffering in always of social lives. Similarly, transport and communication network such as bridges, roads, telephone lines and electricity that linked the San Francisco cities and homes were destructed by the earthquake. The shaking of the water grounds caused water pipes to burst causing water contaminations that also created a significant risk to human health (Parsons & Stein, 2014). Conversely, San Francisco cities and marketplaces that experienced the earthquake faced primary economic impacts during the earthquakes. For example, the San Francisco shops and business were heavily damaged encouraging looting and thefts. The damaged transport and communication networks caused changes or difficulties to trade causing economic challenges (Komar & Ruggiero, 2011). In general, primary effects of the earthquake that may not directly related to San Francisco earthquakes but also occurred in other areas such as Japan and Turkey are hazardous chemicals spillage, radioactivity resulting from damaged nuclear power stations and liquefaction of water related sediments. In addition, floods and tsunami and outbreaks of fires are the primary effects of the earthquake occurrences(Parsons & Stein, 2014). San Francisco secondary earthquake effect Fig5. Illustrating San Francisco earthquake effects on refugee San Francisco secondary effects or impacts are those impacts that are experienced in long-term after the occurrence of the earthquake. For example, the long-term social earthquake impacts include the spread of diseases in the affected areas such as cholera and water contamination related disease. There was re-housing of people some affecting their natural social way of lives that can also be translated to refugee camps in other areas of earthquake occurrences. Similarly, the long-term economic impacts that were caused by the earthquakes were increased costs of building the damaged homes and buildings for settlements. In addition, the investments in the areas affected by the earthquake were main directed into rebuilding the cities and reconstruction of transport and communication networks as advocated by the George Pardee the California governor (Komar & Ruggiero, 2011). The San Francisco long-term environmental effects are the loss of both the natural and human landmarks. Similarly, the outbreaks of fires triggered by electric cables and gas lines caused fires to spread quickly through the San Francisco Cities, homes and market areas. However, Tsunami and landslides, soil liquefaction and diseases persistent in the San Francisco affected areas causing a greater challenge to human life (Parsons & Stein, 2014). San Francisco Earthquake Responses and Mitigation Plan Strategies San Francisco cities, county, and the entire surrounding areas are consistently subjected to earthquake occurrences in subsequent years causing greater destructive effects to human life, building structures and utility systems. After the 1906 San Francisco earthquake, many lessons were learned providing opportunities for the San Francisco Bay regions to design an earthquake preparedness and mitigation strategies for effective communication and responsible for potential earthquake occurrences and effects. Therefore, despite the San Francisco earthquake increasing frequency and severity, the effects are prevented and mitigated by initiation and implementation of earthquake safety measures (Komar & Ruggiero, 2011). The earthquake effects preparedness and mitigation in the San Francisco since the 1906 earthquake occurrence have been achieved by the United States government providing supportive information to cantonal and federal that reinforces earthquake mitigation activities in those areas. At the community, private and cantonal levels the United States government in conjunction with all earthquake mitigation and program agencies in providing relevant information that creates earthquake occurrences awareness and safety preparedness (Sucuoğlu & Akkar, 2014). For instance, after the occurrence of the 1906 San Francisco earthquake occurrences, the affected area were provided with preventive measures for the earthquakes such as evacuation programs, seismic safety housing building, and emergency education. In addition, the San Francisco Bay regions developed the Pacific earthquake mitigation and safety programs such as San Francisco Earthquake and Fire, the Earthquake Safety Implementation Program (ESIP) and San Francisco General Services Agency (GSA). Collective, these agencies provide earthquake preparedness, response, mitigation and rehabilitation services to victims and their properties (Parsons & Stein, 2014). Conclusion The San Francisco earthquakes occurrences, causes and their effects since 1906 is a complex subject that can only be achieved through collective bargains. Therefore, the severity, frequency, history and the mechanisms of San Francisco earthquake occurrences provides a turning point in which the San Francisco earthquake preparedness, response, mitigation and rehabilitations strategies can be initiated and implemented. The San Francisco earthquake are caused by the Pacific tectonic plate colliding with the North American plate subducting and grinding against other along the San Andreas fault causing vibrations spreading in all directions resulting in seismic waves and eventually earthquakes. Long-term and short-term earthquakes effects were experienced in San Francisco affect social, economic and environmental aspect of human life. Environmental effects examples are Tsunamis, landslides, fires whiles social effects examples are the disruption of transport and communication networks. References Cox, R. T., & Geological Society of America. (2012). Recent advances in North American paleoseismology and neotectonics east of the Rockies. Boulder, Colo., USA: Geological Society of America. Eberhard, D. A. J., Zechar, J. D., & Wiemer, S. (September 01, 2012). A prospective earthquake forecast experiment in the western Pacific. Geophysical Journal International, 190, 3, 1579-1592. Komar, P. D., Allan*, J. C., & Ruggiero, P. (September 01, 2011). Sea Level Variations along the U.S. Pacific Northwest Coast: Tectonic and Climate Controls. Journal of Coastal Research, 27, 5, 808-823. Parsons, T., Segou, M., Sevilgen, V., Milner, K., Field, E., Toda, S., & Stein, R. S. (December 28, 2014). Stress-based aftershock forecasts made within 24 h postmain shock: Expected north San Francisco Bay area seismicity changes after the 2014 M = 6.0 West Napa earthquake. Geophysical Research Letters, 41, 24, 8792-8799. Sucuoğlu, H., & Akkar, S. (2014). Basic earthquake engineering: From seismology to analysis and design. Read More