Using the S-P time, determine the epicentral distance of each station to the earthquake using a travel time curve. Use a map and graphical compass to draw arcs of radii equal to the epicentral distances around each station. Where these arcs overlap, you may approximate your epicenter.
How do you find the epicenter distance from three different seismographs?
Determine the epicenter distance from three different seismographs. The longer the time between the arrival of the P-wave and S-wave, the farther away is the epicenter. So the difference in the P- and S-wave arrival times determines the distance between the epicenter and a seismometer.
How do you estimate the distance from the stations to the earthquake?
Distances from the stations to the earthquake are estimated from the difference between P and S wave arrival times: Illustrative example seismograms from IRIS. Use the time difference between the arrival of the P and S waves to estimate the distance from the earthquake to the station.
How do I view the seismograms for an earthquake?
To the right you will also see seismograms. Scroll to the bottom of the webpage for your chosen earthquake, beneath the earthquake info and seismograms to view the list of stations that recorded the shown seismograms. Choose the station that was closest in distance to the earthquake (see the furthest column to the right).
How can seismic records be used to determine the location of an earthquake?
Seismic records can be used to determine the location of the epicentre of the earthquake. The time lag between the arrival of the P and S waves at a seismometer station can be used to determine the distance of the epicentre from the station.
How do seismograph stations help determine an earthquake's epicenter?
Each seismograph records the times when the first (P waves) and second (S waves) seismic waves arrive. From that information, scientists can determine how fast the waves are traveling. Knowing this helps them calculate the distance from the epicenter to each seismograph.
How do you find the epicenter from three seismographs what if you have more seismographs involved?
Finding the Epicenter Determine the epicenter distance from three different seismographs. The longer the time between the arrival of the P-wave and S-wave, the farther away is the epicenter. So the difference in the P- and S-wave arrival times determines the distance between the epicenter and a seismometer.
How do you find the epicenter of a seismograph?
Finding the Epicenter One seismogram indicates the distance to the epicenter. This is determined by the P-and S-wave arrival times. If a quake is near the seismograph, the S-waves arrive shortly after the P-waves. If a quake is far from the seismograph, the P-waves arrive long before the S-waves.
How do seismologist determine the distance from the source of an earthquake?
Seismologists use the difference in arrival time between P and S waves to calculate the distance between the earthquake source and the recording instrument (seismograph). Seismograph sites need to be on hard rock and well away from traffic and other sources of artificial ground noise.
Why is it important to get three seismic data from three stations to calculate the epicenter of an earthquake?
At least 3 earthquake recording stations are required to find the location of the earthquake epicenter. A single recording station can only calculate distance, but not direction; to cover all possibilities, a complete circle is drawn around that station.
How many seismographs are needed to find the epicenter of an earthquake Why is this number significant?
Seismic stations detect earthquakes by the tracings made on seismographs. Tracings made at three separate seismic stations are needed to locate an earthquake epicenter. Objective: To identify the location of an earthquake epicenter using a travel time graph and three seismograph tracings.
How do you find the distance from the epicenter to the station?
Measure the difference in arrival times between the first shear (s) wave and the first compressional (p) wave, which can be interpreted from the seismogram. Multiply the difference by 8.4 to estimate the distance, in kilometers, from the seismograph station to the epicenter.
What is the distance of the epicenter from seismic station?
The distance of the seismic recording station from the earthquake epicenter is determined from the time difference between the first arrival of the P-wave and the S-wave. This is known as the S-P interval.
How do scientists find the epicenter of an earthquake quizlet?
How do geologists locate the epicenter of an earthquake? They use seismic waves to locate an earthquake's epicenter. Scientists measure the difference between the arrival time of the P and S waves to the seismograph. The farther away an earthquake the greater the distance between arrival time.
How do seismographs measure earthquakes?
Seismometers allow us to detect and measure earthquakes by converting vibrations due to seismic waves into electrical signals, which we can then display as seismograms on a computer screen. Seismologists study earthquakes and can use this data to determine where and how big a particular earthquake is.
What will you use to determine the distance the waves have traveled from the origin to that station?
The S - P time interval will then be used to determine the distance the waves have traveled from the origin to that station.
Multiple Seismic Stations
To figure out just where that earthquake happened, you need recordings from seismic stations in other places.
Finding the Distance to the Epicenter
Use the time difference between the arrival of the P and S waves to estimate the distance from the earthquake to the station. (From Bolt, 1978.)
Finding the Epicenter
You have just figured out how far your seismograph is from the epicenter and how strong the earthquake was, but you still don't know exactly where the earthquake occurred. This is where the compass, the map, and the other seismograph records come in.
What is a seismogram?
A seismogram is a record written by a seismograph in response to ground motions (US Geological Survey definition). Seismograms depict the arrival of different earthquake waves to seismograph stations. These waves include both surface waves and body waves.
How to take a screen shot of a map?
If you are using a Macintosh, hold down command, shift, 4 to take a screen shot of your map with the scale. If you are using a PC, press the Windows logo key +PrtScn or press Alt+Print Screen by holding down the Alt key and then pressing the Print Screen key. You may be able to use the Snipping Tool:
Which waves travel with the greatest velocity?
Primary waves travel with the greatest velocity so they reach the station first, followed by secondary waves, then surface waves. The arrival of these waves are recognized on the seismogram by a sharp increase in amplitude and decrease in frequency.
Multiple Seismic Stations
Finding The Distance to The Epicenter
- Measure the distance between the first P wave and the first S wave. In this case, the first P and S waves are 24 seconds apart.
- Find the point for 24 seconds on the left side of the chart of simplified S and P travel time curves and mark that point. According to the chart, this earthquake's epicenter was 215 kilometers away.
- Measure the distance between the first P wave and the first S wave. In this case, the first P and S waves are 24 seconds apart.
- Find the point for 24 seconds on the left side of the chart of simplified S and P travel time curves and mark that point. According to the chart, this earthquake's epicenter was 215 kilometers away.
- Measure the amplitude of the strongest wave. The amplitudeis the height (on paper) of the strongest wave. On this seismogram, the amplitude is 23 millimeters. Find 23 millimeters on the right side...
- Place a ruler (or straight edge) on the chart between the points you marked for the distance to the epicenter and the amplitude. The point where your ruler crosses the middle line on the ch…
Finding The Epicenter
- You have just figured out how far your seismograph is from the epicenter and how strong the earthquake was, but you still don't know exactly where the earthquake occurred. This is where the compass, the map, and the other seismograph records come in. 1. Check the scale on your map. It should look something like a piece of a ruler. All maps are different. On your map, one centime…