Plate Tectonics: Geology Of California

Plate Tectonics is a scientific theory which study how the Earth’s plates are driven and shaped by geological forces to keep them in constant movement. The theory explains the present-day tectonic behavior of the Earth, particularly the global distribution of mountain building, earthquake activity, and volcanism in a series of linear belt. (Pitman, W.C., 2007)

Volcanoes are one of the most destructive, yet, most beautiful things on Earth. They can make a famous city choke in its own ashes in one day, like Pompeii. Or they can turn a once damaging mountain into a graceful and peaceful home for new life, like Mount St. Helen’s. All volcanoes are unique, and no two are the same. Some erupt differently than others, some look different than others, and all are located in different spots all over the world. I learned this while completing the project and the five volcanoes I researched are examples of my discoveries. The five volcanoes I researched were Mount Hood, Mount Mageik, Long Island, Mount Muria, and Las Pilas.

The three faults being considered are thought to have influenced the character of some 120,000 square miles. The Big Pine, Garlock, and San Andreas faults are all mutually active, deep, long, and steep and noted as being conjugate shears. In concert, the faults have defined a primary strain pattern of relative east-west extension and north-south shortening of the area of 120,000 square miles. The large region is noted for its deformity, with the source of this being a northeast-southwest counterclockwise compressive couple. The compressive couple was potentially supported through drag as a result of the deep-seated movement of rock material from the Pacific region (Hill & Dibblee, 1953). The interaction of the faults in the San Andreas region since the Jurassic period have served to shape and contour the present geology of the land, while a study of the paleontology of the region likewise requires such knowledge to effectively determine conditions at any given point in time.

The location of the volcano is also important. If it is situated on a constructive plate boundary then it is generally less explosive, and therefore poses different threats to volcanoes situated on a destructive plate boundary. The volcano may also be situated on a hotspot like in Hawaii, where the eruptions aren’t very explosive. Volcanos which aren’t explosive can pose other threats to lava flows though, such as dangerous gases being released. Like in Lake Nyos, Cameroon where 1700 people died.

The west coast of North America has been tectonically and volcanically active for billions of years. The Sierra Nevada Mountains in eastern California were born of volcanoes, and magma has been erupting in the Long Valley to the east of the mountains for over three million years (Bailey, et. al., 1989). However, the climactic eruption of the region occurred relatively recently in the region's geologic history. About 760,000 years ago, a huge explosion of magma warped the Eastern Sierra into the landscape that exists today. The eruption depleted a massive magma chamber below the earth's surface so that the ceiling of the chamber imploded, forming what is now known as

According to the research report, it will cause thousands of people die, towns submerged, buildings and bridges damaged once a huge earthquake and tsunamis happened on the Pacific Northwest area near American coast. And losses will be estimated at over 5 billion dollar US dollars. This shocking article was composed by seismic safety advisory committee in Oregon. According to materials, a super-strong earthquake once happened in A.D. 1700 Cascadia Subduction Zone (CSZ) on the Pacific Northwest coast. There are some experts forecast that another super-huge earthquake will occur in the future. The report has shown that once the earthquake occurs, the regions from North California to British Columbia Coastal region will suffer devastation, cause heavy casualties. Water and electricity shortage issues definitely follow this heavy disaster, meanwhile, communication and heating system and gas supply will definitely broken off in the light of this earthquake. The CSZ is a 1,000 km long dipping fault that stretches from Northern Vancouver Island to Cape Mendocino in northern California. It separates the Juan de Fuca (Juan

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).

The tectonic setting for the 1906 San Francisco Earthquake was in the outermost shell of earth consisting 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 Pacific Plate (on the west) slides horizontally northwestward relative to the North American Plate (on the east), causing earthquakes along the San Andreas and associated faults. The San Andreas fault is a transform plate boundary, accommodating horizontal relative motions (usgs.gov).

It’s been called the sleeping giant. Myths of California breaking off and floating away into the Pacific Ocean. This myth is one of the most popular to this day. Why? Because of a 800 mile long fault that makes it’s way through California called the San Andreas Fault. Beginning when the East Pacific Rise submerged under the North American Plate about 40 miles away from what is now Los Angeles. Spreading northwest and southeast, The San Andreas Fault or SAF gradually grew, and is still growing. The grinding plates, along with earthquakes, to this day are gradually reshaping California, as we know it. In this paper, we will look at the history of The SAF and learn what it is and what it could be capable of doing.

The right figure gives a more specific visualization of the Juan de Fuca plate currently been forced to slip under the North American plate in an area known as the Cascadia Subduction Zone. Along the boundary of these two plates, a section has become locked yet they are still moving toward each other. As a result, stress has accumulated for centuries and when that stress relieved, it will cause the largest and most powerful earthquake called a megathrust earthquake of magnitude 9.0 or higher. The last earthquake which was caused by the relieved of this stress with similar magnitude happened in 1700. The scientists were able to determine this date through sediment samples that indicated the coast’s seismic past, taken from the sea floor off the coast of Vancouver Island. Therefore, scientist were able to outline that earthquakes occur every 500 to 1000 years.The risk for a possible megathrust earthquake to happen is increasing and it is coming faster than predicted because the stress hasn’t been released recently and the Juan de Fuca and the North American Plates are constantly moving. Right now, Vancouver Island has been tilted higher and squeezed by a few centimetres eastward every year. In the next 50 years, when the strain released, an earthquake called the “Big One” will rip down the west coast from British Columbia to northern California,

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

Plate tectonics is the scientific theory that attempts to explain the movements of the Earth's lithosphere that have formed the landscape features we see across the globe today” (Briney). Geology defines “plate” as a large slab of solid rock, and “tectonics” is part of the Greek root word for “to build.” Together the words define how the Earth’s surface is built up of moving plates. The theory of plate tectonics dictates that individual plates, broken down into large and small sections of rock, form Earth’s lithosphere. These fragmented bodies of rock move along each other atop the Earth’s liquid lower mantle to create the plate boundaries that have shaped Earth’s landscape. Plate tectonics originated from meteorologist Alfred Wegener’s theory, developed in the early 20th century. In 1912, he realized that the east coast of South America and the west coast of Africa appeared to piece together like a jigsaw puzzle. He further examined the globe and deduced that all of Earth’s continents could somehow be assembled together and proposed the idea that the continents had once been linked in a single supercontinent called Pangaea. To explain today’s position of the continents, Wegener theorized that they began to drift apart approximately 300 million years ago. This theory

The fault line is less commonly known as the San Andreas which runs through California – Canada, where it is presumed that ‘The Big One” can be unleashed. The Cascadia Subduction zone is also runs from 700 miles from the pacific Northwest towards Canada. It can cause a lot of damage in the Pacific Northwest—Washington, Oregon and California.

This is only a general overview of the inner workings of volcanoes and their eruptions. For more infomation, visit Volcano World -- The Premier Source of Volcano Info on the Web.

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