Question

6 eating Earthquakes-Tokyo, Akita, and Busan, SE Asia. Using the Circle tab on the Ruler tool, draw a circle for each of the seismograph stations with radii corresponding to your answer for Problem 4. Save each circle after drawing them. Which placemark correctly identifies where the epicenter is located? a. Problem 5a b. Problem 5b c. Problem 5c d. Problem 5d To estimate the Richter magnitude for an earthquake, one must know the distance (km; e.g., answer for Problem 4) of a seismograph station from the earthquake epicenter and the maximum amplitude (mm; -180 mm in the previous simulated seismogram above) of the S wave on that station's seismogram. Using a Richter nomogram (right; essentially a graph with three axes scaled based on Richter's equations to account for distance from the earthquake epicenter), the magnitude can be estimated by drawing a line from the distance axis to the S-wave amplitude axis using the values for that seismograph station. Where the line crosses the magnitude axis is the Richter magnitude for the earthquake. Again, it is best to use seismograms from at least three seismographs to converge on a single best answer. seismogram. BOO 700 600 500 400 a. -210 mm b. -100 mm c. -130 mm 300 200 100 60 30 Distance (kilometers) 8.0 7,0 G.D 6.0 40 -20 S 1.0 Magnitude 500 -200 100 -50 20 10 6 2 "1 Fas 0.2 0.1 6. Determining Richter Magnitude - Tokyo, Japan. Using the simulated seismogram in the Problem 6 placemark from the Tokyo, Japan seismograph station, determine the maximum S-wave amplitude (mm) for the Amplitude (millimeters) d. -170 mm 7. Determining Richter Magnitude - Akita, Japan. Using the simulated seismogram in the Problem 7 placemark from the Akita, Japan seismograph station, determine the maximum S-wave amplitude (mm) for the seismogram. a. -30 mm b. -21 mm. c. -71 mm d. -5 mm

Answer 1

Seismographs can measure the arrival times of S-waves and P-waves to precisely determine the distance to an earthquake's epicenter, key for calculating the Richter magnitude using a nomogram.

Step-by-step explanation:

The measurement of seismic waves using seismographs is a key component in determining the origin and magnitude of earthquakes. With an accuracy of 0.100 seconds for the arrival times of these waves, and knowing the speeds of S-waves (4.00 km/s) and P-waves (7.20 km/s), we can calculate the distance to an earthquake's epicenter. This level of precision, however, may limit the ability to detect underground nuclear tests. The Richter scale is a semi-log plot used to quantify the energy produced by an earthquake, and determining the Richter magnitude of an earthquake requires the use of a Richter nomogram, which correlates the S-wave amplitude recorded by a seismograph with the distance to the earthquake's epicenter.