PPT-Earthquakes and Seismic Waves

ITET G MAGGIOLINI amp The green school network present What is an earthquake An earthquake also known as a quake tremor is the shaking of the surface of the Earth resulting from the sudden release of energy in the Earths lithosphere that creates seismic waves . 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. . 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. Essential . Questions. What are earthquake magnitude and intensity and how are they measured?. Why are data from at least three seismic stations needed to locate an earthquake’s epicenter?. Where are Earth’s seismic belts?. 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.. Earthquakes. What if you knew the epicenter was . 572 . km from Vancouver?. Earthquakes. What if you ALSO know that it is . 884 . km from Prince Rupert?. Earthquakes. Finally, you also know that the epicenter is . Seismic . Waves. . are shock . waves . given off by earthquakes. . There are 2 types:. 1. . Body Waves. . originate from the . focus. (. F. ). travel . through. . the earth. . They’re used to locate . 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 . ANNALS OF GEOPHYSICSVOL 47N 2/3April/June 2004regime consisting of central and local govern-ments canton and county Meanwhile there wasa reform and a standardization of the writing sys-tem From t 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’.. Part 1. Seismic Waves and Interior of the Earth. The behaviour of seismic waves in the different layers of the earth provides the most authentic evidence about the composition and structure of the earth. The different types of waves, generated during the occurrence of an earthquake, are generally divided into three broad categories: . 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. teleseisms. ), the waves of greatest amplitudes are generally surface waves that have followed the Earth’s 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 . (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 . Kurdistan Region- Iraq. Ministry of Higher Education . & Scientific Research. . Salahaddin. University- Erbil. Geology - 3th Year. 2. nd. Semester . Jan. . 202. 1. Lec.1. 2. Seismic Method . (Applied Seismology).