Name: _______________ Block:__________________ Science 10 Lab Activity 18A – Where was that Earthquake? Question: ___________________________________________________________________ ____________________________________________________________________________ Experimental Design: In this experiment you will be taking data that has already been collected and analyzing it to find the epicenter of an earthquake. Materials: see page 532 of BC Science Probe 10. Procedure: Follow the flowchart below Find location of each station on map sheet Conclusion: Answer in complete sentences the questions attached Measure the time difference between SP wave arrivals (S-P lag time) found on back sheet. Enter the data below The point at which all the circles cross is the location of the earthquake Interpolate from graph (attached sheet) the distance to the epicenter. Enter the data below. Using the compass, draw a circle around each station that has a radius equal to the distance interpolated from the graph Data: Location S-P Time Lag (s) Distance From Epicentre (km) Conclusion: (Write in complete sentences) 1. Which seismograph was furthest from the epicentre? Which was the closest? 2. Where was the epicentre of the earthquake? Write as a distance from a major population. 3. How many seismograph stations are needed to locate an epicentre? 4. If zero on the seismograph indicates 5:35 am, determine the time that the earthquake occurred to the nearest minute. 5. Currently scientists all over the world share their seismograph data using the Internet. Computers analyze data from hundreds of seismographs. Describe how this amount of data sharing changes the speed and accuracy with which earthquakes can be located.