...___________________________________________ Plate Tectonics Exercise (20 points) PLATE BOUNDARIES There are three different types of lithosphere plate boundaries associated with different types of topographic features and tectonic activity. These are: Divergent boundaries (also called “spreading centers). At divergent boundaries, plates are moving apart. The most common kind of spreading center is the midocean ridge where new ocean floor is created. Spreading may also take place within a continent. In this case, blocks of crust may drop down as the land is pulled apart, creating a rift valley. Convergent boundaries These boundaries involve collision of lithosphere plates, which may occur in three different circumstances. 1. Oceanic – continental plate convergence. If the edge of an oceanic plate collides with the edge of a continental plate a subduction zone is formed. The denser oceanic plate subducts (plunges) beneath the continent, producing a deep oceanic trench. As the oceanic lithosphere descends, partial melting of the rock along the contact zone occurs. The magma that is produced rises toward the surface and produces a chain of volcanic mountains on the land mass parallel to the collision boundary, such as the Andes in South America. 2. Oceanic – oceanic plate convergence. In this case, subduction also takes place. A deep ocean trench forms along with a chain of volcanic islands. An example of such an island arc is the Aleutian Islands in Alaska. 3. Continental – continental plate convergence. If...
Words: 1880 - Pages: 8
...tsunamis are grim at best this excerpt came from Voltaire’s Candide a French satire published during Europe’s Age of Enlightenment. This gives a chilling view of Lisbon on All Saint’s Day (November first) in 1755. What had occurred is a 200 km offshore 8.5-9.0 magnitude earthquake that resulted in a large-scale tsunami and rampaging fires, effectively killing thousands of people. This is one of the deadliest tsunamis recorded in history, but how do tsunamis function and what do we know about their inner workings. Tsunamis since the early 1600s have been synonymous with some form recording of “shaking of the earth”. Very rarely do you see other forms of tectonic activity such as volcanic eruptions or glacier calving that can create a tsunami. The integral part to the large-scale tsunamis that we see is plate tectonics. The plates converge, diverge, or transform to create a Figure [ 1 ]: Shows an example of what is happening in a subduction related tsunami zone. (PNSN, 2013) Figure [ 1 ]: Shows an example of what is happening in a subduction related tsunami zone. (PNSN, 2013)...
Words: 1674 - Pages: 7
...Plate Tectonics Press Release Public Education on Earthquake Preparedness By Krystle Wilson March 28, 2014 Los Angeles, CA – Earthquakes occurs frequently in Los Angeles and its surrounding areas in California. I would like to take some time today to discuss earthquake preparedness and discuss descriptions of hazards associated with earthquakes in Los Angeles. I will also discuss the origin and causes of earthquakes, relation to the shifting plates to the natural process of mountain building, relation of earthquakes to plate tectonics and faults in Los Angeles. I will share some historical disasters associated with past earthquakes and discuss potential of future earthquake events. Descriptions of hazards associated with earthquakes in Los Angeles Earthquakes occurs and it occurs where there are tectonic plates or fault lines. The main earthquake hazard is the effect of ground shaking. The ground shaking can create hazards with buildings that may potentially collapse, roads may be unleveled, ground may split open. Because of Los Angeles being a large city with large population of people and buildings, there are gas lines running underneath the city. If an earthquake occurs, it may cause rupturing of the pipe line which could lead to fires and explosions. (Michigan Tech, n.d.). Origin and causes of Earthquakes “The earthquakes in California in general are caused by the movement of huge blocks of the earth’s crust – the Pacific and...
Words: 966 - Pages: 4
...Plate Tectonics Nicole Anderson GLG/220 Dr. A. Kem Fronabarger November 7, 2011 What is an Earthquake and where do they come from? Many people are unaware of what an actual earthquake is and how they come to be. There are several myths that have been created to help people understand how earthquakes have been produced. In Japan, legend has it the earth is shaken by the movement of a giant catfish hidden in the ground. The Chinese believe that the earth is resting on a giant ox, and in India, one myth suggest that the earth was held in place by four elephants, which were standing on top of a giant turtle, which in turn was standing on top of a giant cobra; whenever one animal moved, the earth is shaking (Zerve, 2000). In the 1960’s we finally found the true cause of earthquakes. The theory of plate tectonics was created. This theory suggests that the earth’s crust consists of “plates” that move relative to one another, and seismic activity is associated mostly with this motion (Zerva, 2000). Most of the earthquake sources are located along the boundaries of these plates. Earthquakes can be very hazardous, so it is important to understand how an earthquake happens and the earthquake preparedness techniques. In order to understand the earthquakes and the tectonic plates, we must first understand the earth and its layers. The earth is made up of three layers: the crust, the mantle and the core (Zerva, 2000). The lithosphere is the crust and upper most solid mantle...
Words: 912 - Pages: 4
...The Earth: It’s Shifting Plates & the Consequences The Earth is a combination of sand, rocks, molten lava; this definition would force one to conclude that our world is a contradiction in terms. This is not the case, we dwell on solid rock that is the surface of the Earth; the overwhelming facets of the Earth exist below the surface. It is here that we will find the tectonic plates of the Earth and cause for Earthquakes. An earthquake occurs as the two blocks of the earth suddenly slip past one another (usgs.gov). Generally a quake will occur without warning, although many times there may be a foreshock (smaller earthquake near epicenter, similar to an aftershock), which is usually mistaken for the Earthquake until the actual higher magnitude quake occurs. These shifts seem to happen without warning, however, upon observation and tracking of geological survey, structures, and pattern, it is possible to decipher the probable location of an earthquake. The United States Geological Survey map is a valuable tool when attempting to decipher whether a particular state is an Earthquake hotspot. Upon review of the Geological survey, one will notice that Pacific coast and the islands in the Pacific Ocean are furthermost susceptible to the quakes. Hazard levels range the low teens to over fifty percent. Kentucky, Tennessee and Missouri rest on the New Madrid Fault line; subsequently these are states that share the red zone symbolizing the greatest risk for activity. We will...
Words: 1437 - Pages: 6
...to plate tectonics. The term “bathymetry” originally referred to the ocean’s depth relative to sea level, although it has come to mean “submarine topography,” or the depths and shapes of underwater terrain. In the same way that topographic maps represent the three-dimensional features of overland terrain, bathymetric maps illustrate the land that lies underwater. The ocean has mountain ranges, volcanoes, trenches, canyons, and other structures. The oldest rocks on the ocean floor are 180 million years old. This is young compared with the oldest continental rocks, which date from 3.8 billion years ago. While the continental crust has been steadily accumulating throughout Earth’s history, it seems the oceanic crust is created and destroyed rather quickly. It is created at the mid-ocean ridges from hot material rising in the mantle, and then spreads away from the ridges, before eventually being recycled into the mantle at subduction zones. Continental crust is always less dense and more buoyant than oceanic crust, so where they meet, it is the oceanic crust that gives way, sinking (subducting) back into the mantle The boundaries of a tectonic plate may be divergent, convergent, or transform. At divergent boundaries, the crust is extended, thinned, and fractured by the upwelling of hot mantle material. The crust buoys up, producing a mid-ocean ridge, and lava is extruded through a central rift valley to create new oceanic crust. Seamount volcanoes may also arise. Tectonic plates...
Words: 838 - Pages: 4
...spots are anomalies in the pattern of volcanic activity upon plate margins. They are often in the middle of plates. A hot spot can be described as a small area of the earth’s crust where an unusually high heat flow or plume is associated with volcanic activity. Of approximately 125 hot spots thought to have been active over the past 10 million years most are located well away from plate boundaries. It is the fact that they have posed so much trouble for plate tectonic theories, as they don’t fit with the general trend that most seismic and volcanic activity happens at margins. There are several examples of volcanic activity away from plate boundaries such as Yellowstone national park. These hot spots are formed by huge columns of up swelling lava because of radioactivity within the earth, these columns are known as plumes. The plume of plastic molten rock that pushes upwards; causing pressure to drop and the plastic thin rock to become molten, melting and pushing through the crust above. These plumes lie in fixed positions under tectonics plates. As the plate moves over the hot spot, the upwelling lava creates a steady succession of new volcanoes that migrate across the plate. These plumes can be up to 1000km across. The emperor sea mount chain is a good example of plume activity; showing the variation of activity within the succession as the plates move over the plume. This chain extends 5000km along the Pacific Ocean. The first hot spot seen in the chain is the Lohi volcano...
Words: 401 - Pages: 2
...Name(s): __________________ and _____________________________ Section (lab day) _________ Lab 2: Plate Tectonics & the Origin of Magma – AGI 9th ed. Read Lab 2 p31-56. The aim of the lab is: A. To investigate some aspects of the plate tectonic model. B. To interpret rates and directions of plate movement C. To analyze data and associated geological processes & features. The theory of plate tectonics is a powerful and far-reaching theory encompassing many aspects of geology. The theory explains such diverse phenomena as mountain building on continents, the evolution of ocean basins, magma chemistry, the long-term migration of plants and animals, climatic change and the movement of continents. Turn to Lab 2 in the lab manual and read the introduction to each Part, then answer the questions in the manual in the corresponding spaces provided below. Introduction: Earth’s Size, Continents & Ocean Basins 1.1.a Read p 31-32. What was Alfred Wegener’s observation that led him to propose the Continental Drift Hypothesis ___________________________________. (1) 1.1.b Why was this rejected?___________________________________________. (1) Why did anti-drift scientists oppose this and what was their evidence or bias? _____________________________________________________________. (1) 1.1.c What alternative hypothesis did Bernard Lindemann (1927) and Otto Hilgenberg (1933) propose? _______________________________________________....
Words: 3082 - Pages: 13
...Abstract Large igneous provinces are conspicuous features of late Phanerozoic geology, and include continental flood basalts, rifted continental margin volcanic sequences and oceanic plateaus. Many large igneous provinces can be associated with mantle plumes. Where plumes ascend beneath spreading ridges, their energy is transformed into a large melt volume, producing over-thickened plateau crust. Comparing the timing of mass extinctions with the formation age of large igneous provinces reveals a close correspondence in several cases. The Columbia River Basalt Group is a large igneous province, which covers parts of the western United States. There are significant landforms associated with this formation that provide evidence as to the age and controlling mechanisms of its emplacement. 1. Introduction Large igneous provinces (LIPs) are massive emplacements of extrusive and intrusive mafic rock. Processes other than seafloor spreading form these mass emplacements and they are the primary mechanism of terrestrial magmatism on earth. LIPs are distinguishable from mid-ocean ridge magmatism and arc magmatism on the basis of petrologic, geochemical, geochronological and physical volcanological data. Large igneous provinces occur in both continental and oceanic crust.(Coffin and Eldholm, 1991). The purpose of this review is to give an overview of the types of LIPs, their formation, and the possibility of their contribution to mass extinction events. 2. Types of Large Igneous...
Words: 1623 - Pages: 7
...Associate Level Material History of Rock Worksheet Leah Bechtel 12/09/2012 SCI/245 Robert Dillon Write a 500- to 750-word explanation regarding the role of plate tectonics in the origin of igneous rocks. The role of plate tectonics in the origin of igneous rock is extremely important. Igneous rock is formed from magma that reaches the continental and oceanic crust or through hot spots that are around the world. There are three different places where igneous rocks can form; where the lithospheric plates pull apart at mid ocean ridges, where plates come together at seduction zones, and where continental crust is pushed together making the crust thicker and allowing it to heat to a melting point. The word igneous comes from the Latin word for fire, igneous rocks start off as a hot, fluid material which is usually erupted from the Earth’s surface as lava, or magma at shallow depths or deep depths. Magma is a mush like material that can carry a load of minerals, but people often think of lava and magma as a liquid like material of molten metals. The three types of igneous rocks are extrusive, intrusive and platonic rocks. Extrusive rocks are rocks that form and cool on the crust of the Earth whether it is on the continental crust or the oceanic crust. Extrusive rocks cool quickly, within a few seconds to months and they have invisible or very small grains; extrusive rocks have an aphanitic texture. Intrusive rocks are rocks that form within already existing rocks causing...
Words: 957 - Pages: 4
...northern California and symbolizes the dynamic geologic processes that have shaped a spectacular landscape. 63829_02_insidecover.qxd 11/25/08 12:53 AM Page ii ESSENTIAL QUESTIONS TO ASK Northern California.1 Introduction Ⅲ What are northern California’s physiographic provinces? Ⅲ What is the Farallon subduction zone? al Ⅲ What two types of plate boundaries exist in northern California today? th Ⅲ What are terranes, how do they originate, and why are they important in northern California? Northern California.2 The Sierra Nevada: California’s Geologic alifornia’s Ge Backbone Ⅲ What is the Sierra Nevada batholith? rra batholi Ⅲ What kinds of rocks surround the Sierra Nevada batholith? ra Ⅲ When and how was the modern Sierra Nevada uplifted? e Ⅲ What types of gold deposits occur in the Sierra Nevada? e? Ⅲ What is the Mother Lode? Northern California.3 The Klamath M Mountains t ath an Ne evada Ⅲ In what ways are the Klamath Mountains and the Sierra Nevada similar? ds ro o ath M Ⅲ What kinds of rocks comprise the ophiolites in the Klamath Mountains and what tectonic events do they signify? ineral occu th ntai Ⅲ What mineral resources occur in the Klamath Mountains? Northern California.4 The Gr Ca rnia e Great Valley fa s th i he Valle Ⅲ What factors have led to the formation of fertile soils in the Great Valley? at t ime y Grea Seq Ⅲ What was the origin of the sedimentary rocks in the Great Valley Sequence...
Words: 29429 - Pages: 118
...on the Mississippi River and interstate 55. It has a population of 3154 residents, and it is considered as a small community in United States. New Madrid, MO is located at 36.59° North latitude, 89.53° West longitude and about 89 meters altitude above the sea level. Geographic coordinates: Latitude: 36.59° North Longitude: 89.53° West Altitude: 89 m [pic] 3. General geologic setting: A state’s general geologic setting basically includes what types of rock has build up the overall region, what structural features that state has, like, mountains and faults. It also includes plate tectonic setting and also an overall geologic map. 3.1. Geologic map: [pic] 3.2. Plate tectonic setting: The middle of the North American tectonic plate actually contains the new Madrid fault zone. One of the attribute of this plate is, this plate is thinner and weaker near to its center. As a result, it formed a rift zone....
Words: 2629 - Pages: 11
...Francisco were $20 million and outside the city was $4million.The Earthquake vibration lasted for about 1 minute. The quake ruptured a total of 290 miles of the earth's surface along the San Andreas Fault, from northwest of San Juan Bautista to the triple junction at Cape Mendocino. Though most of the damage was focused in San Francisco the quake was felt all the way from Oregon to Los Angeles. Many building were destructed and several hundred of people got killed. The earthquake happened on the San Andreas Fault, which is the major fracture of the Earth's crust. It is trending northwestward through southern and northern California, US for 650 miles (1,050 km) and passing seaward in the vicinity of San Francisco. Movement along this transform fault is of the strike-slip type and is characterized by occasional large earthquakes originating near the surface along the path of the fault. The disastrous San Francisco quake of 1906 and the less serious earthquake of 1989 were both caused by movement along the fault. According to the theory of plate tectonics, the San Andreas results from the abutment of two major plates of the Earth's crust, the Northern Pacific and the North American. Along the fault, the Northern Pacific plate is sliding past the North American plate in a northerly direction, at a relative movement of about 1 cm per year over geologic time, though the rate of movement has been 4 to 6 cm per year over the past century. Parts of the fault line moved as much...
Words: 751 - Pages: 4
...Director of Earthquake Preparedness, Los Angeles FOR IMMEDIATE RELEASE 05th September 2012 Earthquake Preparedness Los Angeles, California – Earthquakes usually occur without any warning given to public and has the capability of enormous destruction which could lead to severe loss of lives and huge destructions. Natural disasters like earthquakes-preparing ahead of time can help us to save lives, protect our property and increase the pace of recovery. There are few simple steps that should be followed for preparing for such natural calamities like earthquakes. Southern California has a very high seismic activity. The San Andreas Fault is the largest and very famous fault in California. Because of a number of such faults, California is highly prone to earthquakes. In the past 100 years, there have been 4 major earthquakes in Los Angeles: Long Beach in 1933, San Fernando in 1971, Whittier Narrows in 1987 and the Northridge Quake in 1994. One of the most well-known earthquakes of California is the earthquake of San Fransisco in 1906. The magnitude of 7.8 collapsed the buildings in this region. Only after this quake, earthquake measuring instruments were developed and scientific techniques were created. The long beach earthquake very narrowly avoided a major disaster because of the timing. It could have led to severe life losses if it happened sometime before the actual one. In this area of Los Angeles, small tremors are always felt. The greatest Southern California earthquake...
Words: 923 - Pages: 4
...SCIN 136 Midterm Exam All Possible Questions http://www.homework-bank.com/downloads/scin-136-midterm-exam-all-possible-questions/ Question 1 Early voyagers used a variety of observations to help guide them including: A. their sense of smell B. cloud formations C. the appearance of more birds D. the direction of waves E. all of the above Question 2 The scientific theory about the formation of the oceans is that they first formed from (the original source of the water): A. Magma displacements. B. comet impacts C. degassing of the early Earth D. all of the above E. both b and c Question 3 Besides the Navy the primary organizations who carry out “classified” A. The U.N. B. Green Peace C. Sierra Club D. Oil companies. E. Boeing F. the banking industry Question 4 One use today of the Navy’s SOSUS System is to monitor________ to prevent loss of life. A. dumping of waste in the oceans B. tsunamis C. fish populations D. oil drilling E. tidal cycles F. surfing championships Question 5 The two types of technology that are mostly used to monitor deep-water oil drilling and to locate and recover deep shipwrecks are: A. AUV’s and compasses B. ROV’s and Side-scan sonar C. GPS and radar D. Chronometers and sextants E. B.P. stock price forecasts and FEMA bureaucrats. Question 6 The reason that ancient sailors had trouble calculating their LONGITUDE is that they did not have reliable A. sextants ...
Words: 2936 - Pages: 12
