PPT-1 On seismic records of distant earthquakes (

teleseisms the waves of greatest amplitudes are generally surface waves that have followed the Earths surface and not penetrated the interior The exceptions are seismograms of deep focus earthquakes which are not effective generators of surface waves so that the body waves are more prominent The dominance of surface waves on . Mr. Altorfer. Science. EARTHQUAKES. Earthquakes. A. . . What are earthquakes?. 1. . . Earthquakes. are vibrations in the ground that result from movement along breaks in Earth's lithosphere.. 2. . The forces that move . -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.. 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. of significant seismic quiescence in the Pacific Mexican . coast. A. . Muñoz-. Diosdado. , A. H. Rudolf-Navarro, . A. Barrera-Ferrer, F. Angulo-Brown. National . Polytechnic Institute, . Mexico . City, . 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. Chapter 2 Section 3. Objectives. F.2.3.1. Explain how a seismograph works.. F.2.3.2. Describe how Geologists monitor faults.. F.2.3.3. . 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.. Part 3: Earthquakes.   . outline differences in P, S and L energy waves produced by an earthquake .   . identify energy transfers and transformations involved in L waves as they travel along the earth’s crust . 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. Earthquake Mechanisms. Brittle Mechanical Model: “stick-slip”. Focal point: 3D point inside the lithosphere where the seismic event occurs. Epicenter: projection of focal point to the map surface . 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’.. For a quick laugh…. Geologists use 2 terms when discussing the location of an earthquake:. Focus. . = The area beneath Earth’s surface where the rock that is under stress actually breaks.. Epicenter. (Page 51). BEFORE, you learned. • Most earthquakes occur along tectonic plate boundaries . • Different directions of stress cause normal, reverse, and strike-slip faults. NOW, you will learn. • How energy from an earthquake travels through Earth .