Hypothesis
My hypothesis is that the epicenter will be where all the three circles meet, because that point will show where all the seismic waves actually started. Right now, I really have no idea where the earthquake might be, but I am predicting it will be somewhere around Tennesse, Kentucky, or Alabama.
1. Observe the three circles you have drawn. Where is the earthquake's epicenter?
The earthquake's epicenter is in Tennesse. I can conclude this because all the circles, representing seismic waves, meet in Tennesse. The seismic waves were last located in Denver, Colorado, because the difference in P and S wave arrival times was the biggest (2 minutes 40 seconds). This Tennesse earthquake affected almost the whole U.S., except the west part (North Carolina, South Carolina, Georgia, New York, Maine, etc).
2. Which city on the map is closest to the earthquake's epicenter? How far, in kilometers, is this city from the epicenter?
I think that the city closest to the epicenter is Nashville, Tennesse. Nashville is a fairly big city, and I guess that it was affected a lot by the earthquake. Nashville is around 100 kilometers from the epicenter, which is VERY close. It must have been a devastating earthquake for the citizens of Nashville :(. I find it really strange that the earthquake is in Tennesse, though. There are no plate tectonic boundaries near Tennesse, so I am really wondering what caused the earthquake.
3. In which of the three cities listed in the data table would sesismographs detect the earthquake first? Last?
I think that the seismographs would first detect the earthquake in Chicago, Illinois. I think this because the primary and secondary waves would reach this city first, since it is the closest to the epicenter of the earthquake. The last place the earthquake would be detected is Denver, Colorado, and the difference between the primary and the secondary waves is the largest. The "middle" city would be Houston, Texas.
4. About how far from San Francisco is the epicenter that you found? What would be the difference between P and S arrival times for a recording station in San Francisco?
San Francisco is around 3, 200 kilometers from the epicenter. I measured this by using a scaled map, and a compass. I used the graph that we were given to figure out that if it there is 3, 200 kilometers from San Francisco to the epicenter, the difference between the arrival times of primary and secondary waves is around 4 minutes 40 seconds.
5. What happens to the difference between the P and S waves arrival times as the distance from the earthquake increases?
As the distance from the earthquake gets bigger, the difference between arrival times of primary and secondary waves grows, as well. You can see this from several examples. San Francisco is the furthest away from the epicenter, and it has the biggest difference between the arrival times of the two types of waves.
6. Review the procedure you followed in this lab and then anser the following question. When you are trying to locate an epicenter, why is it necessary to know the distance from the epicenter for at least three recording stations?
It is necessary for several reasons. If you do not know the distance from the place to the epicenter, then you cannot use the graph (oh which I took a picture below) to figure out the difference between the arrival times of primary and secondary waves. Also, when you are detecting where did the seismic waves go, and where they meet, you need more then one circle, to be exactly sure. If you have less then two circles, your data is probably not that accurate.
My hypothesis is that the epicenter will be where all the three circles meet, because that point will show where all the seismic waves actually started. Right now, I really have no idea where the earthquake might be, but I am predicting it will be somewhere around Tennesse, Kentucky, or Alabama.
1. Observe the three circles you have drawn. Where is the earthquake's epicenter?
The earthquake's epicenter is in Tennesse. I can conclude this because all the circles, representing seismic waves, meet in Tennesse. The seismic waves were last located in Denver, Colorado, because the difference in P and S wave arrival times was the biggest (2 minutes 40 seconds). This Tennesse earthquake affected almost the whole U.S., except the west part (North Carolina, South Carolina, Georgia, New York, Maine, etc).
2. Which city on the map is closest to the earthquake's epicenter? How far, in kilometers, is this city from the epicenter?
I think that the city closest to the epicenter is Nashville, Tennesse. Nashville is a fairly big city, and I guess that it was affected a lot by the earthquake. Nashville is around 100 kilometers from the epicenter, which is VERY close. It must have been a devastating earthquake for the citizens of Nashville :(. I find it really strange that the earthquake is in Tennesse, though. There are no plate tectonic boundaries near Tennesse, so I am really wondering what caused the earthquake.
3. In which of the three cities listed in the data table would sesismographs detect the earthquake first? Last?
I think that the seismographs would first detect the earthquake in Chicago, Illinois. I think this because the primary and secondary waves would reach this city first, since it is the closest to the epicenter of the earthquake. The last place the earthquake would be detected is Denver, Colorado, and the difference between the primary and the secondary waves is the largest. The "middle" city would be Houston, Texas.
4. About how far from San Francisco is the epicenter that you found? What would be the difference between P and S arrival times for a recording station in San Francisco?
San Francisco is around 3, 200 kilometers from the epicenter. I measured this by using a scaled map, and a compass. I used the graph that we were given to figure out that if it there is 3, 200 kilometers from San Francisco to the epicenter, the difference between the arrival times of primary and secondary waves is around 4 minutes 40 seconds.
5. What happens to the difference between the P and S waves arrival times as the distance from the earthquake increases?
As the distance from the earthquake gets bigger, the difference between arrival times of primary and secondary waves grows, as well. You can see this from several examples. San Francisco is the furthest away from the epicenter, and it has the biggest difference between the arrival times of the two types of waves.
6. Review the procedure you followed in this lab and then anser the following question. When you are trying to locate an epicenter, why is it necessary to know the distance from the epicenter for at least three recording stations?
It is necessary for several reasons. If you do not know the distance from the place to the epicenter, then you cannot use the graph (oh which I took a picture below) to figure out the difference between the arrival times of primary and secondary waves. Also, when you are detecting where did the seismic waves go, and where they meet, you need more then one circle, to be exactly sure. If you have less then two circles, your data is probably not that accurate.
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Honestly, I think that there wouldn't be a lot of epicenters in this area, and that this earthquake in Tennesse is very rare. Earthquakes are very common on the boundary of the North American plate, and the Pacific plate. This is on the West Coast, or California. When earthquakes occur here, some of the very strong ones could potentially affect the places where this earthquakes occur, because seismic waves travel through and on the ground. I found it very weird that the epicenter was in Tennesse, very near Nashville o.O. On the earthquake rick map it shows that Tennesse has lower risks of earthquakes, but earthquakes can still occur.
A recent earthquake happened in Kraljevo. The magnitude of this earthquake was 5.3, and even though this is not very high, the effects were devastating. Houses were ruined, and people were without homes. The government had to build small, plastic and metal houses, to keep the people warm in the winter, and enable survival. This earthquake happened around 1:56 a.m., and it was felt as far as Belgrade!
Well written. You were able to use the data and find out the distance to the epicenter of three cities in the US. This enabled you to find the epicenter in Tennessee which is in the Eastern US. This is a medium risk zone because of the mountain range of the North Atlantic plate and the North American Plate coming together. Good job! I like how you questioned the data as well as why an Earthquake could happen there.
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