EARTH SCIENCE
EARTHQUAKES
|
Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
|
|
|
They measure the difference between seismic waves on three or more seismographs. The epicenter is where the circles intercept.
|
|
|
They measure the difference between seismic waves on the first seismograph to receive the wave.
|
|
|
They measure the largest surface wave to hit the surface.
|
|
|
They add the total damage of the p wave, s wave and surface wave.
|
Detailed explanation-1: -Scientists use triangulation to find the epicenter of an earthquake. When seismic data is collected from at least three different locations, it can be used to determine the epicenter by where it intersects. Every earthquake is recorded on numerous seismographs located in different directions.
Detailed explanation-2: -Triangulation can be used to locate an earthquake. The seismometers are shown as green dots. The calculated distance from each seismometer to the earthquake is shown as a circle. The location where all the circles intersect is the location of the earthquake epicenter.
Detailed explanation-3: -You need one because the epicenter will be somewhere along that circle. You need three because three is the minimum number of circles that will intersect at one point.
Detailed explanation-4: -A circle is drawn from each of the three different seismograph locations, where the radius of each circle is equal to the distance from that station to the epicenter. The spot where those three circles intersect is the epicenter (Figure 13.12).
Detailed explanation-5: -Seismographs. Seismographs are instruments used to measure seismic waves. They measure the vibration of the ground using pendulums or springs. The seismograph principle involves mounting a recording device solidly to the earth and suspending a pen or writing instrument above it on a spring or pendulum.