Case Study : San Andreas Fault

The San Andreas fault line has caused constant development nightmares for large urban areas such as San Francisco as well as the other cities built on top of it. Fault lines are one of the side effects of the earth’s tectonic plates shifting that can result in devastating earthquakes. Some of the most devastating earthquakes in our modern era have occurred along the San Andreas fault line due to a dense population. The most notable and destructive earthquake on the San Andreas fault line occurred in San Francisco in 1906. The reason this earthquake was so deadly was because of its magnitude and the city’s poor planning. This earthquake was a wakeup call for San Francisco and force the city to revolutionize its knowledge on earthquakes and how to protect their city. Today San Francisco is one of the most well prepared cities for an earthquake and has made great discoveries in earthquake safety measures. The 1906 earthquake in San Francisco has drastically changed how the city has developed its zoning and building code policies, and its earthquake research.

According to Townend and Zoback (2004) the San Andreas Fault (SAF) region has been noted for its possession of stress orientations in addition to the lack of a distinct heat flow anomaly at the trace of the fault. These findings indicate that there are average shear tractions that are less than 20-25 MPa in the seismogenic upper crust. Oftentimes, shear tractions measure approximately 5 times greater than in the SAF. Due to the presence of high

If you were like me, you would never have thought that Mississippi would ever have to deal

California’s unique geography as a state makes it a very appealing place to call home. From the odd east to west transverse San Gabriel mountain ranges of the Los Angeles Basin, to the bumpy coastal ranges of the Bay Area, any person can find a compatible topographic terrain to their liking. California may seem to be the perfect place to live with its ideal climate and extensive geographic features. However, due to California’s location over the shifting continental plates, coupled with its enormous and also multiple faults, at any time this great state can fall victim to a seismic disaster. After examining evidence from both Rong-Gong Lin’s II Los Angeles Times article of April 18, 2016 and the NOVA videos Killer Quake ( 2006), Earthquake (2007), as well as Geologic Journey II – Episode 3 (The Pacific Rim: Americas) – Part 3 (San Francisco) and The Great San Francisco Earthquake (American Experience ~ 2005), one can take a comparative account of the three major earthquakes of California’s past. Although each earthquake was very devastating on is own; the Great Quake 0f 1906, the Loma Prieta quake of 1989, and the NorthRidge quake of 1994 each amounted to an extensive forfeiture of property and life. Each of these earthquakes created much suffering and loss. It is imperative for each citizen of this great state to understand the damage that a California quake can actually do and be prepared; for the threat of one always looms.

The city has a mild year-round climate with an average of 201 days above 70 degrees. A sign of global warming is that the average surface temperature of the water has increased 3 degrees since 1950. San Diego lies on approximately 200 deep canyons and hills, creating small pockets of natural open space scattered throughout the city and giving it a mountainous geography. Due to this scattered open space, it causes a significant change in climate over short geographical distances. The San Diego River runs through the middle of San Diego while several reservoirs lie between and also separate the developed areas. The city also runs through two fault zones, the Rose Canyon and Point Loma faults, which are part of the San Andreas Fault system. It

The earthquake was located on the San Andreas fault which is a seismic zone between two of the earth’s tectonic plates. Seismic events which occur is caused as a result of the earth’s tectonic plates moving against each other and this can cause huge earthquakes and volcanoes (“Young”). The transform boundary passes through California and this is where the Pacific and North American plates move past each other without colliding. The event in which this occurred was the San Andreas fault (“Young”). When the plates move past each other and the resistance builds up, this causes an earthquake like the 1906 San Francisco earthquake. This earthquake caused a separation and displacement in the landscape which was seen over several kilometers

On August 24, 2014 a magnitude 6.0 earthquake occurred in and around the city of Napa, CA. The earthquake killed one person and injured over 150 people. And these people were treated at Queen of the Valley Medical Center in Napa [1]. More and more earthquakes occurred on this earth. So this grasps people’s attention.

• This earthquake may not have released all of the strain stored in its rocks next to the fault this reveals a potential earthquake in the Santa Cruz Mountains in the near future. The occurrence of the earthquake showed that the Earth did not exhaust all its strain and hence other earthquakes could be expected. However, the dates could not be predicted. The extent of the damage could have been much more devastating for the region, but with the earthquake occurring near the coast this made half of the felt area westward in the Pacific Ocean. The occurrence of aftershocks ten days later reinforces the unpredictability nature and hence makes Geology to be a study that is always evolving. In conclusion, the Earth and the study of cannot be exhausted as every natural occurrence provides a new puzzle to be solved.

The 1906 San Francisco Earthquake tectonic setting was in the outermost shell of earth known as the crust this is composed of rigid plates that have been moving for hundreds of millions of years. Two of these moving plates meet in western California; the boundary between them is a zone of faults, the principal one being the San Andreas fault. The horizontal sliding of the Pacific Plate relative to the North American Plate, causes earthquakes along the San Andreas fault and similar plates near the region. The San Andreas fault is a transform plate boundary, accommodating horizontal relative motions (usgs.gov).

In recorded history, there have been 151 earthquakes in Nevada that were a magnitude of 3.5 or higher. As previously mentioned, the mountain ranges of Nevada are typically bound on one side or the other by a fault. There are quaternary faults that range in ages from less than 150 years to around 1.8 million years in existence. The property damage in Nevada from earthquakes was .2 million dollars between 1196 and 2014 based on information from department of energy for the state. As we studied in our textbook, earthquakes can by a number of things, such as shifting faults, or volcanic

California, and thus San Francisco, lies on the San Andres fault. The earthquake was caused when this fault suddenly shifted, with the rupture spreading for a total of 476 kilometres in northward and southward direction. “This fault is a continental transform fault, which forms part of the tectonic boundary between the North American Plate and the Pacific Plate.” (1906 Earthquake: How long was the 1906 Crack? USGS Earthquake Hazards Program – Northern California, Accessed September 3, 2006). 1 The distance of the fault is of about 1300 kilometres, which runs the length of California from Cape Mendocino in the north to the Salton Sea in the south. Geologists have estimated that the fault moved as quickly as 2.74 kilometres per second. The San Andreas Fault, the source of this disaster, lies ten miles or deeper, at the meeting point of two tectonic plates, the Pacific and the North American. “The right-lateral strike-slip fault is characterized by mainly lateral motion in a dextral sense, where the western plate (Pacific plate) moves northward relative to the eastern plate (North American

The Northridge earthquake in 1994 caused widespread damage to not only the northern ridge area of Los Angeles but created major transportation issues for surrounding communities.

California is due to be hit by an earthquake with an high magnitude of 8.0 comparable to the 1906 San Francisco 7.6 earthquake.

Earthquake Hazards occur when there are adverse effects on human activities. This can include surface faulting, ground shaking and liquefaction. In this essay I will be discussing the factors that affect earthquakes, whether human such as population density, urbanisation and earthquake mitigation or physical such as liquefaction, magnitude, landslides and proximity to the focus.

The San Andreas Fault is one of the most widely studied faults in the world. Scientists use an array of methods in collecting data and providing analysis of fault characteristics both past and present. Presently there are many differing hypothesis and models used to describe crustal movements and deformation within the Pacific and North American plate boundary. Historical earthquakes along this fault have proven to be rather large and devastating. This is important since the San Andreas Fault runs along many highly populated areas throughout Northern and Southern California. Through further research and analysis of this fault system scientists hope to solve