Epicenters By Jo Ann Byron Shady Springs Junior High 1.The mathematical solution for each situation is calculated as follows: Arrival time of S-wave minus P-wave times 2 miles per second (speed of S-wave) times 3 miles per second (speed of P-waves) equals the distance of epicenter from seismograph. By doing some of the fixed calculations first, a short version of the previous equation would be:: Arrival time of S-wave minus arrival time of P-wave times 160 equals distance to epicenter from seismograph. 2.Here are some representative data for students to use for practice P-wavesS-wavesDistance from epicenter Hawaii12:0012: miles Alaska11:0811: miles California10:4310:48__________ miles Cuba10:0010:10.41__________ miles Iceland10:0110:07.94__________ miles Italy10:0210:10.33__________ miles 3.Use a world map with a scale. Have students draw circles, to scale, around each of the locations given in the chart. The radius of their circles should be equal to the calculated distance from the earthquake epicenter. The common point defined by an overlapping of circles reveals the geographic location of the epicenter 1.The mathematical solution for each situation is calculated as follows: Arrival time of S-wave minus P-wave times 2 miles per second (speed of S-wave) times 3 miles per second (speed of P-waves) equals the distance of epicenter from seismograph. By doing some of the fixed calculations first, a short version of the previous equation would be:: Arrival time of S-wave minus arrival time of P-wave times 160 equals distance to epicenter from seismograph. 2.Here are some representative data for students to use for practice P-wavesS-wavesDistance from epicenter Hawaii12:0012: miles Alaska11:0811: miles California10:4310:48__________ miles Cuba10:0010:10.41__________ miles Iceland10:0110:07.94__________ miles Italy10:0210:10.33__________ miles 3.Use a world map with a scale. Have students draw circles, to scale, around each of the locations given in the chart. The radius of their circles should be equal to the calculated distance from the earthquake epicenter. The common point defined by an overlapping of circles reveals the geographic location of the epicenter Preparation and one 45-minute period. A tsunami is a seismic sea wave that can be caused by an earthquake. They travel an average of 400 miles per hour. To determine how long it will take a tsunami to hit a given area, divide 400 into the distance from the epicenter to the “hit” area. To calculate distance to epicenter from seismograph using arrival times of P- waves and S-waves. To find on a map the location of the epicenter of an earthquake. To calculate distance to epicenter from seismograph using arrival times of P- waves and S-waves. To find on a map the location of the epicenter of an earthquake. Compass World Map Ruler, edge of paper, or string Calculator (optional) Compass World Map Ruler, edge of paper, or string Calculator (optional) Students can accurately calculate the distances from the epicenter. Students correctly identify the location of the epicenter. Students can accurately calculate the distances from the epicenter. Students correctly identify the location of the epicenter. None listed Objective Materials and Equipment Materials and Equipment Time Procedures Assessment Further Challenges Further Challenges Overview Teaching Suggestions Safety Note