The Creation of the Ocean Floor
Anitreas Weeks
SCI/209
January 26, 2013
Cynthia Collin-Clausen
The Creation of the Ocean Floor When most individuals think about the ocean they visualize water, and the creatures of the sea. Rarely do individuals think about the sea floor or the creation process of it. Sea floor spreading and plate boundaries are not a common subject to anyone outside of a scientific or marine biology lab. The purpose of this paper is to identify plate boundaries. Compare and contrast ideas behind plate tectonics and the theory of the continental drift. There are many types of plate boundaries. Each one
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According to "Plate Tectonics" (2010), “Two plates sliding past each other forms a transform plate boundary. Natural or human-made structures that cross a transform boundary are offset—split into pieces and carried in opposite directions. Rocks that line the boundary are pulverized as the plates grind along, creating a linear fault valley or undersea canyon” (transform plate boundary). The activities of plate boundaries have a direct effect on nature. One natural occurrence that is a direct result of plate boundary interaction is earthquakes. This natural disaster causes worldwide devastation. When people hear the word earthquake the first thought is fear. For many the word earthquake is associated with loss of life, homes, and total destruction. The phenomena are described as a vibration in earth’s surface caused by eruptions or movements along a fault line. Earthquakes are not restricted by boundaries and time zones they have occurred in areas all over the globe. The brief description previously mentioned is only a portion of what earthquakes are. In actuality the movement of plate tectonics below the earth’s surface influences how earthquakes begin. According to United States Search and Rescue Task Force (2000), “Huge plates that form the Earth's surface slowly move over, under, and past each other. Sometimes the movement is gradual. At other times, the plates are locked together,
There are three different types of plate boundaries. The first type of plate boundaries is, the spreading boundary. A spreading boundary is when two plates move apart. The spreading boundary is also known as a divergent boundary. The second type of plate boundary is a colliding boundary. A colliding boundary is when two plates come together, or collide. It is also known as convergent boundary. The third is, a sliding boundary. A sliding boundary is when two plates slip past each other moving in opposite directions. It is also known as transform boundary. Those were the three different types of plate
Earthquakes can be created on any of the plate boundaries. Earthquakes occur when tension is released from inside the crust. Plates do not always move smoothly alongside each other and sometimes get stuck. When this happens pressure builds up. When this pressure is eventually released, an earthquake tends to occur. The point inside the crust where the pressure is released is called the focus. The point on the Earth's surface above the focus is called the epicentre. Earthquake energy is released in seismic waves. These waves spread out from the focus. The waves are felt most strongly at the epicentre, becoming less strong as they travel further away. The most severe damage caused by an earthquake will happen close to the epicentre.
There are three distinct types of plate boundaries existing, which are supported by geological observation, geophysical data, and theoretical considerations. Their names and categories are based on if adjacent plates move apart from each other (divergent plate margins), toward one another (convergent plate margins), or slip past one another in a direction parallel to their common boundary (transform plate margins) (Pitman, W.C., 2007).
The theory of plate tectonics states that Earth’s outer shell is divided into plates. The crust and upper mantle is broken into plates that move around on the mantle, changing in size throughout time. The lithosphere makes up the crust and upper mantle and the asthenosphere a plastic like layer beneath the lithosphere. There are three types of plate boundaries. Divergent boundaries where two plates move away from each other. The ocean widens and new crust forms at the mid-oceanic ridge. Convergent boundaries has three types of converging, moving two plates towards each other. First we have an ocean floor plate that collides with a less dense continental plate. Next an ocean floor plate collides with another ocean floor plate. Finally a continental plate collides with another continental plate. Transform boundaries were two plates slide past one another. The resulting effects of plate tectonics is landforms such as rift valleys,
Over more than 50 decades there has been multiple earthquakes that have been caused by the activity that takes place beneath and above the surface of the earth. For every earthquake there are various effects and consequences, these are generally not preventable but teachable moments. As we study and explore landforms we learn and better understand how today 's structures came about, what took place decades ago and where do we go from here. Thanks to the technology and inquiring minds we are able to study past events like the 1906 San Francisco earthquake and the 1964 Alaska earthquake. In comparing these two events we can get an overview of what happened and better prepare ourselves for something like that in the future.
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).
Of all the naturally occurring events on Earth, earthquakes are among the most devastating and bring a lot of truth to the statement, “Just because something is natural does not mean it is not dangerous.” Earthquakes are one of the most natural things I can think of that can cause massive damage and loss of human live in many instances, and the effects are sometimes long term. “Nothing happens without a force. Many geophysicists accept the theory that continents move as a result of the forces generated by mantel convection deep within Earth – motions driven by our planet’s internal heat energy” (Trefil & Hazen, 2010). According to National Geographic (1996-2012), constant movement in the tectonic plates that make up the Earth’s
The first few seconds of your first earthquake are disconcerting. You don’t know what’s happening. The undulation, the noise, the inability to focus -- it’s all disconcerting. But once you’ve been in a few, you know the feeling. You don’t relax, but you don’t panic, either.
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
Earthquakes are caused when two blocks of earth suddenly slip past one another. The surface where the two blocks slip is called the fault. The earthquake starts below the earth’s surface at the hypocenter, and the location above the hypocenter is called the epicenter. Earthquakes can have foreshocks which is a smaller earthquake that happens before the larger quake. Earthquake can also
Plate tectonics move land masses around, and occasionally, interactions between different plates causes new land to form, and can even join two separate continents together, changing ocean currents and causing climate change. This is evident in the collision of the North and South American continents, which created the Isthmus of Panama, and separated the Pacific and Atlantic Ocean. Approximately 15 million years ago, the North and South American continent was cut off from each other by a seaway about 200 km wide. Over time, the South American plate collided with the Caribbean and Cocos plate, and gradually closed the exchange of the Caribbean and Pacific waters 3-4 million years ago. This resulted in several consequences.
The breaking apart of this supercontinent was due to the movement of the Earth's Tectonic Plates. Tectonic Plates are large masses of the lithosphere or outer layer of the Earth's surface. The layers included in the Lithosphere are the Crust up to the upper layer of the Mantle. The Oceanic Crust is thinner and denser than the Continental Crust and can be found underneath the ocean. It is also more active than the Continental Crust that stretches 200 km below the Earth's surface. This crust drifts and moves either horizontally or vertically causing geological phenomenons such as earthquakes, volcanic eruptions, etc. The major tectonic plates are North American, Caribbean, South American, Scotia, Antarctic, Eurasian, Arabian, African, Indian, Philippine, Australian, Pacific, Juan de Fuca, Cocos, and Nazca. These plates move an estimate of 1 to 10 cm per year causing interaction at plate boundaries. When two plates are colliding or moving toward each other it is in Convergent boundaries. If these two plates are Oceanic Crusts, they are in Subduction zones wherein the denser plate in forced beneath the less dense plate and would eventually melt or destroy. On the other hand, when two plates move away from each other it is in Divergent boundaries. New crust material from molten magma formed below may fill the space between these plates or become ocean basins.
7. What is the relationship between plate tectonics and the ocean floor—seafloor spreading, for example?
Natural or human-made structures that cross a transform boundary are offset—split into pieces and carried in opposite directions. Rocks that line the boundary are pulverized as the plates grind along, creating a linear fault valley or undersea canyon. As the plates alternately jam and jump against each other, earthquakes rattle through a wide boundary zone. The lithosphere is the solid, outer part of the Earth. The lithosphere includes the brittle upper portion of the mantle and the crust, the outermost layers of Earth’s structure. The lithosphere is divided into 15 major tectonic plates: the North American, Caribbean, South American, Scotia, Antarctic, Eurasian, Arabian, African, Indian, Philippine, Australian, Pacific, Juan de Fuca, Cocos, and
An Earthquake is the shaking of the earth's surface caused by rapid movement of the earth's rocky outer layer. The sudden shaking of the ground that occurs when masses of rock change position below the Earth's surface is called an earthquake. The shifting masses send out shock waves that may be powerful enough to alter the surface of the Earth, thrusting up cliffs and opening great cracks in the ground.