PPT-Monitoring Earthquakes

Chapter 2 Section 3 Objectives F231 Explain how a seismograph works F232 Describe how Geologists monitor faults F233 Explain how seismograph data is used The Seismograph Seismic waves cause the seismographs drum to vibrate but the suspended weight with the pen attached moves very little Therefore the pen remains still and records the vibrations on the drum. By. : 10 grade. What is an earthquake ?. Simply, earthquakes are the rumblings, shaking or rolling of the earth's surface. It is usually what happens when two blocks of the earth suddenly slip past one another, or break apart from each other as a result of tension caused by prolonged energy build up. . -Black. Shensi, China. When did this happen?. January 23, 1556. How many people died?. It is estimated that 830,000 people where killed in it.. The geological effects that were reported where ground fissures, uplift, subsidence, liquefaction, and landslides.. Deformation. The process of when a rock changes because of stress. Compression. -rocks push together (squeezing). Tension. -rocks pull away from each other (stretching). Rock layers bend when stress is placed on them. But when the stress is placed on rocks, they can reach their elastic limit and break. The Earths crust . The earths crust is in constant motion.. Volcanoes and earthquakes arise as sections of crust push . toghether. or pulled apart. Volcanoes and earthquakes are more common in certain parts of the world. By monitoring ground vibrations scientists can sometimes. Earthquakes are very difficult to predict.. Scientists understand why they happen, but it is very difficult to predict their . timing, exact location, and . strength. Pressure. build-up happens underground, over very long periods of . Earthquake. – shaking and trebling that results from the movement of rock beneath Earth’s surface.. Plate movement causes earthquakes from stress and faults in Earth’s crust. When the rock breaks earthquakes happen. Comparing and contrasting earthquakes. Have compared the impacts of earthquakes on a . MEDC. and a . LEDC. .. Have considered development as a key issue in . earthquake response. .. By the end of this section, you will: . Miles P. Wilson. Gillian R. Foulger, Jon G. . Gluyas. , Richard J. Davies & Bruce R. Julian. British Seismology Meeting. 5. th-. 7. th. April 2017. 1. Disclaimer and terminology. Study background. Earthquakes result from sudden motions along breaks in Earth’s crust and can affect landforms and societies.. An entire branch of Earth science, called . seismology. , is devoted to studying earthquakes.. An . earthquake. is a shaking of the ground caused by the sudden movement of large blocks of rock along a fault. Earthquakes occur along faults.. A . fault. is a fracture, or break, in Earth’s lithosphere, along which blocks of rock move past each other.. William Mackaness, Carol Blackwood, Charlotte Graves. Institute of Geography. School of GeoSciences. University of Edinburgh. Drummond St, Edinburgh EH8 9XP. william.mackaness@ed.ac.uk. Earthquakes. Measure on a Richter scale 1-7. . What Is an Earthquake?. An . earthquake. is the vibration of Earth produced by the rapid release of energy. Energy released radiates in all directions from its source, the . focus. . Energy is in the form of waves. By: Dan Arrington. EAS 4480. Spring 2012. Image obtained from: http://www.survival-goods.com/What_is_an_Earthquake_s/269.htm. Background Information. Richter Scale. Measures magnitude. Energy released. An earthquake is a motion of the ground surface.. According to A.N. . Strahler. and A.H. . Strahler. ,(1976), ‘An earthquake is a vibration or oscillation of the surface of the earth caused by a transient disturbance of the elastic or gravitational equilibrium of the rocks at or beneath the earth the surface’..