...Eartquake What is an earthquake? An earthquake is what happens when two blocks of the earth suddenly slip past one another. The surface where they slip is called the fault or fault plane. The location below the earth’s surface where the earthquake starts is called the hypocenter, and the location directly above it on the surface of the earth is called the epicenter. Sometimes an earthquake has foreshocks. These are smaller earthquakes that happen in the same place as the larger earthquake that follows. Scientists can’t tell that an earthquake is a foreshock until the larger earthquake happens. The largest, main earthquake is called the mainshock. Mainshocks always have aftershocks that follow. These are smaller earthquakes that occur afterwards in the same place as the mainshock. Depending on the size of the mainshock, aftershocks can continue for weeks, months, and even years after the mainshock! Causes of earthquakes and How earthquakes happen The earth has four major layers: the inner core, outer core, mantle and crust. (figure 2) The crust and the top of the mantle make up a thin skin on the surface of our planet. But this skin is not all in one piece – it is made up of many pieces like a puzzle covering the surface of the earth. Not only that, but these puzzle pieces keep slowly moving around, sliding past one another and bumping into each other. We call these puzzle pieces tectonic plates, and the edges of the plates are called the plate boundaries. The plate...
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...Earthquakes are one of Mother Nature’s most powerful forces and have plagued our lives for as long as people have inhabited the earth. These dangerous acts of the earth have been the cause of many deaths in the past century. So what can be done about these violent eruptions that take place nearly without warning? Predicting an earthquake, until now, has almost been technologically impossible. However, with recent improvements in technology and science, many lives have been saved and many more will be. What is an earthquake and how do they occur? Did you know that most of the famous mountains are a result of an earthquake? (Cosmeo, 2008) That tidbit of information was just a little side note; now back to the paper. Earth is a planet that is made up of multiple layers. These layers include an inner layer and an outer layer and layer in between. The inner layer of the earth is a ball of molten rock that rotates within the earth. The other layers that are on top of the inner layer are floating about as a pliable ball of molten rock. The outer layer is what we refer to as the crust. The crust is very thin when compared to the other layers of the Earth. For example, think of the outer layer of an orange as it relates to the interior of the orange. This example relates closely to what the Earth looks like when we examine the crust. The crust and other layers floats upon the mantle core. The crust of the earth is made up of multiple pieces. Each of these giant pieces is called a tectonic...
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...Earthquakes Christina OBanion Instructor Kryger SCI/245 February 28, 2010 Earthquakes have been happening for a long time, but now we are able to help detect where and possibly when these events might happen. They now seem to be getting stronger than they were in the past and even more frequent. No matter when or where earthquakes happen people always need to be aware that they have the potential to be devastating for those close by, or even those who are on the other side of the world. Earthquakes happen several different ways and I will try to explain this. The Earth has different types of plate margins that can cause earthquakes. The first type of plate margin is called the divergent margin, this is when oceanic or continental lithospheric plates move apart from each other due to mantle convection and new crust is created by magma pushing up from the mantle. The majority of these divergent margins are located in the ocean. One example of this type of margin on land is the Imperial Valley of California/Mexico. Another type of plate margin is the convergent margin and this happens when two plates move together or converge meaning one plate sinks (is subducted) under another. There can be three different types of convergences: oceanic-oceanic, oceanic-continental, continental-continental. One place where oceanic-continental convergence has occurred is off the coast of South America, along the Peru-Chile trench. The Nazca Plate (oceanic) is pushing into and being...
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...Assignment: Earthquakes Sci/245 Assignment: Earthquakes Plate margins are involved in the Earth as a major provider to many of Earth’s geological formations. These plates are approximately 100 kilometers thick, which is very thin compared to the largeness of a 6000-kilometer radius of the Earth. Most major plates include both continental crust and oceanic crust. An earthquake is the shaking of the Earth’s crust due to a sudden release of energy. They are caused by stress that builds up between two lithospheric plates. When two plates slide next to each other, friction usually prevents the plates from moving. Instead of moving, the stresses on the plates cause the plates to change shape. Eventually, the stresses on the plates come great enough to overcome friction, and the plates suddenly move, causing an earthquake. The earthquake releases the stress, and builds up more again over time. Earthquakes generally occur along faults. A fault is a break or crack in Earth’s crust along which movement has occurred. An earthquake produces waves called seismic waves, which transmit energy. Seismic waves are detected and recorded by a device called a seismograph. A seismograph detects ground movements—either horizontal or vertical motions. The set of jagged lines recorded on paper is called a seismogram. There are different types of seismographs, depending on the types of earthquakes intended to record. Most modern seismographs are electronic devices rather than mechanical...
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...Earthquakes Tresha Yarberry University of Phoenix Earthquakes Everyone wonders how earthquakes happen. Although, scientists have no way of predicting earthquakes, there are ways to find out how and what causes them. People can be prepared if an earthquakes happens. There are three different types of plate margins. The first one is divergent margin, also called rifting or spreading centers. This occurs where two plates are moving apart. They can occur either in continental or oceanic crust. When a plate is being stretched or torn apart, this creates a rift valley. A new ocean may form in the widening rift. A good example of this is when the Red Sea formed. Where oceanic crust is splitting apart, the result is a midocean ridge. (Physical Geology, 2005). The earthquakes that happen at midocean ridges are shallow and indicate that plates are moving apart. The plates move apart at a divergent margin, the high pressure is released, allowing the mantle rock to melt. The lava flows up into the slowly widening crack. Some of the lava flows out onto the sea floor to cool, and the rest is added to the plate edge to slowly cool. The second type of plate margin is convergent margins. This occurs when two plates move toward each other. This leads to different types of margins, depending on whether the boundary is between two oceanic plates, two continental plates, or one of each. When one continent meets another continent along a convergent...
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... Learning Goals (Earthquakes 4/5) •! •! List and describe the primary earthquake hazards Understand the importance of building design and ground conditions in earthquake damage to buildings and infrastructure Understand the basics of how buildings can be designed or retrofitted to better resist earthquakes (and reduce casualties and costs) Explain liquifaction and resonance and how those processes can affect buildings •! •! Upcoming Dates and Deadlines Field Trip sign-up now open: Sign-up and pay in ECAC (see schedule online) Saturday, September 21: Earthquakes Quiz due Monday, September 23: Review session (here) 4-6 pm Bring your questions! Wednesday, September 25: Midterm #1 - 30 multiple choice - 2-stage exam (will explain on Monday) - covers all material through Monday !7"/+3)7$+8)43)*4"9:+ !"#$%&'()$*'+,%*$&-'' ./&'0$12-'3,4'5,'&06'&6/&'78579754$113':;+#"?*)+);)#953)F*+/"#(*++++++++++++++ GH.+95'+E?>>+>)"#3+=#5/+$%)+)7"/+ •! @?$+*?O)+A"#)"CP+*>?@P+"34+*$#)30$%+ G*+/"03?$'4)+?34?30*+ !"#$%&'"()+T3$)3*?$9+ •! G+E4$17&$F96')*D/"$)+5=+%5E+0#5'34+/5D53+ "Q)>?+UT3$)3*?$9F+"$+V5+ Queen Charlotte (Haida Gwaii) earthquake October 28, 2012 Magnitude: Mw7.7 Depth: 20.0 km V IV III ‘Mercalli Scale’ USGS Earthquakes Guatemala quake November 7, 2012 Subduction of Cocos Plate Mw 7.4 Depth: 24.1 km Reported ‘intensity’ is stronger closer to the quake epicentre, but there is a large variation. COCOS PLATE USGS Earthquakes Why? What are...
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...Assignment GEOL1002 Earthquake Portfolio This project will get to you examine the nature and effects of a significant earthquake. You will examine various aspects of the earthquake with your group over the course of the next six weeks. The exercise will get you to examine various sources of data, then you will learn how analyses the different data sets, and present the data in several different ways. The aim is to have you develop your geologic, spatial and temporal and presentation (transferable) skills. During the course of this project will: 1. Describe the tectonic and geologic setting 2. Quantify the characteristics of the earthquake (magnitude, depth, duration etc.) 3. Describe the effects of the earthquake (natural and human) 4. Assess the risk of future earthquakes in the region 5. Present recommendation to help in hazard mitigation in the region 6. Present projects Products (all due Feb 9): i) 2000 word report (fully illustrated and referenced) ii) Poster board iii) 5 minute-long video on YouTube iv) 10 minute powerpoint presentation Each part worth 25% of total assignment grade. Useful websites to get you started: USGS Earthquake Hazard Program: http://earthquake.usgs.gov/ Southern California Earthquake Center: http://www.scec.org/ National Earthquake Hazard Reduction Program: http://www.nehrp.gov/ Group Assignments 1. Haiti earthquake, 2010 | 5. Chile earthquake, 2010 | 2. Tohoku earthquake, 2011 | 6. Northridge...
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...Earthquake From Wikipedia, the free encyclopedia This article is about the natural seismic phenomenon. For other uses, see Earthquake (disambiguation). [pic] An earthquake (also known as a quake, tremor, temblor or seismic activity) is the result of a sudden release of energy in theEarth's crust that creates seismic waves. Earthquakes are measured with a seismometer; a device which also records is known as aseismograph. The moment magnitude (or the related and mostly obsolete Richter magnitude) of an earthquake is conventionally reported, with magnitude 3 or lower earthquakes being mostly imperceptible and magnitude 7 causing serious damage over large areas. Intensity of shaking is measured on the modified Mercalli scale. At the Earth's surface, earthquakes manifest themselves by shaking and sometimes displacing the ground. When a large earthquakeepicenter is located offshore, the seabed sometimes suffers sufficient displacement to cause a tsunami. The shaking in earthquakes can also trigger landslides and occasionally volcanic activity. In its most generic sense, the word earthquake is used to describe any seismic event — whether a natural phenomenon or an event caused by humans — that generates seismic waves. Earthquakes are caused mostly by rupture of geological faults, but also by volcanic activity, landslides, mine blasts, and nuclear experiments. An earthquake's point of initial rupture is called its focus orhypocenter. The term epicenter refers to the point at...
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...Salgado Earthquakes Science SC300 Unit 4 May 12, 2011 Professor Jayne Yenko Earthquakes There are not many things in life that petrify me but earthquakes are pretty high on the list. Just the uncertainty of not knowing if this could be the next big one. Realistically speaking, where can you go to be safe from an earthquake? Luckily for me, there seems to be no great danger of earthquakes in the southeast region of the US. I live in Atlanta, Ga. and according to the map fig.17-22** in our text it seems that we are in a blue low risk area, where individual measurements of seismic wave velocities reveal cooler rocks under the southeastern US. However, just a little further northwest of Georgia according to the seismic map in the USGC website* there seems to be a small area of higher earthquake activity between Missouri, and Tennessee. The Midwest seems to be free of earthquakes while the west coast has an abundance of earthquake activity. California has the 2nd highest amount of earthquake activity in the US, after Alaska that produces more than half the earthquakes in the country. The earth has three major subduction zones. The first is a large area called the pacific ring of fire, this includes North and South America the east coast of Asia, and the western pacific islands of the Philippines, Indonesia, New Guinea, and New Zealand. Most of the plates are being subducted, while some plates scrape past each other. The second major divergent or earthquake zone is...
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...the future. When there is a place that has many low magnitude earthquakes the frequency is typically low. On the contrary when there is a single earthquake with a larger magnitude the frequency can be very high. 2. The P waves(Primary waves) work in a “compressional motion,” also known as body waves. The P waves travel at a speed of 5-8 km/s through the earth. When an event like this occurs it sounds like a low thundering noise. The S waves(Secondary wave) are more inconsistent in their movements. When this event occurs the ground shakes and roads and sidewalks start to rip apart. Even though the P waves are the bulky body waves, the S waves are way more destructive. Surface waves, these include Love and Rayleigh waves. These waves travel in a long pattern stretching out over the waves path. Surface waves move a little slower than the P or S waves, however they can cause way more damage. There are three ways to measure earthquakes; the two types of Mercalli Intensity Scales, Shake maps, and Richter Magnitude Scale. The Mercalli Scales are based on how forceful the shaking is and the amount of the damage done. Shake Maps sometimes show the history and range of ground movement helping to monitor potential earthquakes. The Richter Magnitude Scale is measured on the amplitude of earthquake waves measured on a seismograph. This is the most accurate measuring up to a 6.5 magnitude earthquake. 4. There are three main causes for tsunamis, seismic activity...
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...Earthquakes On October 17, 1989, as my family and I were preparing to watch game 3 of the World Series, a special news break announced that there had been a devastating earthquake that had struck the San Francisco bay area. News cameras quickly began showing the devastation that this magnitude 6.9 earthquake had wrought. Buildings were on the verge of collapse and the two tier bay bridge had partially collapsed trapping hundreds of motorists. 63 people lost their lives due to the earthquake, 3,500 were injured and over 100,000 buildings were damaged (bbc.co.uk, 2005). Earthquakes are notorious throughout history as devastating phenomena, but what causes them? In order to understand what makes the earth tremble so violently, you have to delve deep under the Earth’s surface. At one time, scientists thought that the earth’s crust or Lithosphere was continuous without any breaks or cracks but in the 1960’s, new research showed that the lithosphere was actually a fluid puzzle of irregular segments, or plates. These plates are made up of cool, solid rock that is four to forty miles thick. These enormous blocks of Earth’s crust vary in size and shape and cut through continents and oceans. There are nine major plates. Six of them are named for the continents they are embedded in: the North American, South American, Eurasian, African, Indo-Australian, and the Antarctic. The other three are oceanic plates called the Pacific, Nazca and Cocos plates. These plates are in constant...
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...“Earthquakes have affected the Earth since the solid lithosphere first formed” (Marshak, 201). Mankind learned to adapt through numerous earthquakes, tsunamis, and volcanoes since the beginning of time and this survival involved taking substantial risks. According to Marshak, “Earthquakes are a fact of life on planet Earth: almost 1 million detectable earthquakes happen every year…most cause no damage or casualties, because they are too small or they occur in unpopulated areas” (201). There are very few areas one can live on Earth that is free from some form of hazard. Jobs, economic interest, and necessity are but a few reasons people choose to live in unsafe environments. It is okay to live in earthquake prone areas, you just need to educate yourself and prepare. Make sure you have the proper necessities and learn about emergency preparedness for your immediate area. Earthquakes of an enormous magnitude can cause considerable damage and alter lives in unprecedented ways. The bigger they are the more the environment is affected. One such event is “The 2004 Indian Ocean event…etched in people’s minds because of the immense death toll” caused by a tsunami that “was triggered by an earthquake off Sumatra” causing 15m high waves that pounded the coast (Marshak, 224-225). The aftermath (whether an earthquake, tsunami, volcano, or landslide), is displaced persons, causalities and injuries, disease, transportation, emergency and temporary shelters, and supply chain. Marshak, Stephen...
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...been suspended since last April, because of concerns about foot and mouth disease, according to a spokesman for the United States Department of Agriculture. Poultry and egg imports are barred because the Agriculture Department has not determined that Japan has a sufficient inspection system for those products. Transportations services were shut down during this incident. People were trying to make their way out of this huge disaster but it was not successful. “I never experienced such a strong earthquake in my life,” said Toshiaki Takahashi, 49, an official at Sendai City Hall. “I thought it would stop, but it just kept shaking and shaking, and getting stronger.” This earthquake destroyed families property, disrupted their power, moved their homes, interrupted everyday interaction. When people are in real danger it is not that easy to get away. A lot of people in Japan went missing. The people that were present were being asked to relocate to higher grounds. Not only did this earthquake affect people in Japan, it also had some effects on some other people living in...
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...places like Australia, Los Angeles, Bakersfield, Lockyer Valley, Fisherman’s Warf, Embarcadero, AT&T Park, and also in San Francisco. Actors and actresses who played the role of the characters in the film were absolutely perfect for the roles for they touched the hearts of the audiences in their acts. Though San Andreas is a drama/disaster film, they still succeeded in bringing out the romance of the two of five main characters of the story. San Andreas is another accomplishment in the face of Hollywood films, for they grossed $473 million worldwide. Last February 2016, the producers, New Line Cinema announced a sequel reportedly focus on the Ring of Fire. Johnson, Gugino, Dadario and Giamatti are set to reprise their roles Earthquake- a natural calamity which results to trembling and shaking of the earth’s crust and creates seismic waves. This phenomenon can happen anytime and anywhere. We start to feel the pressure when the inner part of our world slightly moves. After this calamity occurs, our minds will be covered with fear. Also, it was like being...
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...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 notice that...
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