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Vocabulary – Quiz define each term. Focus Epicenter Pacific ring of fire Seismograph S waves. Essential Question Discuss Elastic rebound theory Warm up What do you currently know about earthquakes Exit Task What is New Madrid Homework (if you do not finish in class)
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Vocabulary – Quizdefine each term • Focus • Epicenter • Pacific ring of fire • Seismograph • S waves
Essential Question • Discuss Elastic rebound theory • Warm up • What do you currently know about earthquakes • Exit Task • What is New Madrid • Homework (if you do not finish in class) • Read pages 99 – 111 • Vocabulary – define and give one fact
California Science Content Standards Covered: • Plate tectonics operating over geologic time has changed the patterns of land, sea, and mountains on Earth's surface. As the basis for understanding this concept: • 3D: Students know why and how earthquakes occur and the scales used to measure their intensities & magnitude
Terms Chapter 6 Define and write sentences or draw pictures • Earthquakes • Elastic rebound theory • Aftershocks • Focus • Epicenter • Pacific ring of fire • Fault zones • Seismograph • P waves • S waves • Surface waves • Magnitude • Microquakes • Mercalli scale • Intensity • Tsunami • Seismic gaps
Chapter 6 Introduction • Ring of Fire • How math and Science meet • Earthquakes 1 & 2 • Waves ( NO good)
Discuss the Elastic rebound theory Chapter 6 3D: Students know why and how earthquakes occur and the scales used to measure their intensities & magnitude Elastic Rebound Theory Anatomy of a Quake Epicenter, focus, seismic waves Fore, primary, aftershock Shallow, intermediate & deep focus
Lecture 6.1 pages 99 - 100Discuss the Elastic rebound theory • Elastic Rebound Theory • When a STRESS is applied, the road changes from its original form – ELASTIC DEFORMATION • When the RUPTURE relieves the STRESS, the ground under the road REBOUNDS and returns to its original condition • When the RUPTURE occurs, we feel the EARTHQUAKE
Lecture 6.1 pages 99 - 100Discuss the Elastic rebound theory • Slippage first occurs at the FOCUS • The place on the SURFACE of the Earth under the focus is the EPICENTER
Lecture 6.1 pages 100 – 102Explain why earthquakes generally occur at plate boundaries • 90% of earthquakes have a SHALLOW focus • Intermediate and deep focus earthquakes (10%) occur 70 Km and DEEPER
Lecture 6.1 pages 100 – 102Explain why earthquakes generally occur at plate boundaries • How does the depth of earthquakes explain the type of a boundary?
Lecture 6.1 pages 100 – 102Explain why earthquakes generally occur at plate boundaries • 3 Major Earthquake Zones • Mid Ocean Ridges – mainly divergent • Eurasian-Melanisian Belt – mainly convergent • Ring of Fire – mainly convergent • Each dot represents an EARTHQUAKE ZONE
Chapter 6 Section 2 Objectives • We will be able to compare the three types of seismic waves. • We will discuss the method scientist use to pinpoint an earthquake. • We will discuss the method most commonly used to measure the magnitude of earthquakes.
Lecture 6.2 page 103 – 104compare the three types of seismic waves. • Seismic waves are recorded on a seismograph • 3 Major forms of waves recorded by seismograph • P Waves • S Waves • Surface Waves
Lecture 6.2 page 103 – 104compare the three types of seismic waves. • aka Primary Waves • Travel the fastest • Same direction as particle motion • Travel FASTER through DENSER material • Move through solids, gases and liquids
Lecture 6.2 page 103 – 104compare the three types of seismic waves. • aka secondary or shear waves • SLOWER than P Waves • Travel at RIGHT Angles to particles in motion • CANNOT pass through liquid or gases
Lecture 6.2 page 104 discuss the method scientist use to pinpoint an earthquake. • Method: TRIANGULATION • Must have three (3) seismographs • Calculate the difference in P wave travel from all three
Lecture 6.2 page 104 discuss the method scientist use to pinpoint an earthquake.
Lecture 6.2 page 104 discuss the method scientist use to pinpoint an earthquake. This map shows how the epicenter of the Loma Prieta earthquake was determined using data from three seismic stations. The seismogram at Eureka, CA indicated that the epicenter was 478 km away (red circle). The green circle represents the distance of the epicenter (624 km) from Las Vegas. The blue circle represents the distance of the epicenter (702 km) from Elko, NV. The epicenter is determined by the intersection of all three circles near Santa Cruz, CA. This triangulation technique requires data from at least three seismic stations in order to determine the epicenter.
Lecture 6.2 page 104 – 105 discuss the method most commonly used to measure the magnitude of earthquakes. • Magnitude is a measure of ENERGY RELEASED IN AN EARTHQUAKE • Measured by a RICHTER SCALE • Intensity is the amount of DAMAGE an earthquake causes • Measured by the MERCALLI SCALE
Lecture 6.2 page 104 – 105 discuss the method most commonly used to measure the magnitude of earthquakes. What is the difference between intensity and magnitude? What scales are used to measure each? • End of Chapter Questions • p. 112-113 #8-11
Lecture 6.2 end The seismogram in Pusan, Korea indicated that the epicenter was 549 km away (red circle). The green circle represents the distance of the epicenter (435 km) from Tokyo. The blue circle represents the distance of the epicenter (697 km) from Akita, Japan. The epicenter is determined by the intersection of all three circles in Kobe. This triangulation technique requires data from at least three seismic stations in order to determine the epicenter.
Terms Chapter 6 Section 3 • Tsunami • Seismic waves
Earthquake Damage Most injuries, result of collapsing buildings or falling objects. Types of damage – landslides, fires, broken gas and electric lines, flooding, and damage to dams The longer an earthquake last the more damage it causes Notes section 6.3 – page 106Describe possible effects of a major earthquake on buildings
Destruction to buildings and property Buildings are not designed to sway, walls can collapse, may tip over Type of ground, solid ground offers more support to buildings, loose soil can cause more swaying in buildings Notes section 6.3 – page 106Describe possible effects of a major earthquake on buildings
Tsunamis Caused by underwater earthquakes, that either cause a landslide or faulting underwater. Faulting can change seafloor elevation, forcing the water to move up and down. Underwater landslide can cause this same up and down motion. Notes section 6.3 – Page 106Discuss the relationship of Tsunamis and Earthquakes
Tsunamis There is an early warning system to alert areas of tsunamis. Notes section 6.3 – Page 106Discuss the relationship of Tsunamis and Earthquakes
Earthquake Safety Before an earthquake Be prepared – have canned food, bottled water, flashlights, batteries and a portable radio. Plan what to do when a earthquake happens Learn how to turn off gas, water and electricity to the house. Notes section 6.3 – pages 107-109List safety rules to follow when an earthquake strikes
Earthquake Safety During an earthquake Stay calm and get to a safe position Indoors – protect yourself from falling objects. Outside – stay away from tall buildings, power lines, bridges, or tunnels Notes section 6.3 – pages 107-109List safety rules to follow when an earthquake strikes
Earthquake Safety After the earthquake Check for hazards, always wear shoes, and avoid power lines Notes section 6.3 – pages 107-109List safety rules to follow when an earthquake strikes
Earthquake warnings & predictions Animals behavior & past earthquakes used to predict future earthquakes, may be years off Fault stress measured to determine seismic gaps, to determine where a quake may happen. Instruments used to detect crust tilting, rock stress, water flow changes, electro magnetic changes to predict earthquakes. Decreases in P-wave speed may tell when a quake is coming. Most methods are not very reliable in predicting an earthquake Notes section 6.3 – pages 110 – 111Identify changes in the earth’s crust that may signal earthquakes