PPT-GY111 Physical Geology Earthquakes and Seismic Waves

Earthquake Mechanisms Brittle Mechanical Model stickslip Focal point 3D point inside the lithosphere where the seismic event occurs Epicenter projection of focal point to the map surface . 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. ● What is Seismology?. ● What are Seismic Waves?: Types of Seismic waves. ● Where do Earthquakes Happen?. ● Why do Earthquakes Happen?. ● How is the Epicenter of an Earthquake Located?. ● How are Earthquakes Magnitude Measured?. 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. 1. 2. 3. 4. 5. 6. 7. 8. 9. _______________. _______________. _______________. _______________. _______________. _______________. _______________. _______________. _______________. The plate . boundaries. 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 . 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 . ITET G. . MAGGIOLINI . & . “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 Earth's lithosphere that creates seismic waves. . This topic will shake you up. Stress. Stress-. a force (energy) that acts on rock to change its shape or volume. Types of Stress. Tension-. pulls or stretches rock so that it becomes thinner in the middle. This happens at divergent plate boundaries.. An . earthquake. is a sudden motion or trembling of the Earth caused by the abrupt release of energy that is stored in rocks. . Modern . geologists know that most earthquakes occur along plate boundaries, where huge tectonic plates separate, converge, or slip past one another. 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. Seismic waves: terminology, classification, the transfer of energy, how waves move. Measuring earthquakes. Layers of the Earth and seismic waves. What information a seismologist is able to interpret from a seismogram. 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).