Observe the three circles you have drawn. Where is the earthquake's epicenter?
I drew 3 circles and at the place were it creates a border, this border is the earthquake's epicenter. Here the epicenter is on the border of Kentucky.
Wich city on the map is closest the earthquake's epicenter? How far is the city from the epicenter, in kilometers?
 The closest city is chicago and it is about 600 km away from the earthquake's epicenter
In which of the three cities listed on the data table would seismographs detect the Earthquake first? Last?
I think that the closest cities to the epicenter would feel it first and the farthest last. So first Chicago, then Houston and finally Salt lake city.
 How far from San Francisco is the epicenter you found? What would be the difference in arrival times of the P waves and S waves for a recording station in San Francisco?
It would take it about 4:40 to arrive at san francisco.
What happens in arrival times between P waves and S waves as the distance from the earthquake increases?
P waves and S waves have more chances of meeting and the force of the earthquake has diminished a lot.
Review the procedure you follwed in this lab and then answer 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?
The more recording stations (or circles) we have the more precise we can be. I there are like 10 points we would probably only have something like 2mm in comun, so we could be precise. But if we only had 1 recording station the epicenter could be anywhere inside the center.

Wave Lab

Guiding question/ hypothesis
When watter is droped from a piplette into a bucket of water how does the water behave?
It will create a disturbance called wave. That will go in circles around the place were the water was droped.
How do waves interact with each other and with objects in their path?
I think that they stop each other .

Observation:

I observed that the drops make a few circular waves that feel the whole bucke. I also saw that the waves bounce off of solid objects  in their way. Even if some parts of the waves will go "around it". But each "barrier" or solid in the wave's way made it slow down, it is why at one point it did come to an end.

Conclusion

I had some parts of my hypothesis right, it did create waves, but I was wrong, the solid objects didn't destroy the wave but just made it bounce of and/or go around.

Wave lab

Guiding Question: How does the thickness of string affect the sound that goes through it?”

 Hypothesis: I think it will travel better through thicker strings

Variables:  I will keep the 2 plastic glass and the same length for each strings, but I will change and try different thicknesses of strings. And my response should be different forces of sound waves..

Materials: 2 plastic glass, one knife, Small sowing string, medium size string, thick string

Procedure:

1)    With a knife make on small holes at the bottom of both glasses

2)    Pass one of the type of string threw each hole and make a knot at each of it’s extremities.

3)    Test the “telephone” by talking threw it from one end and listening threw the other .

4)    Record the amount of sound it produced.

5)    Repeat the procedure with each different string materials you have

6)    Compare your data

Record and Analyze:

Thin sowing string: When we talked threw the “phone” we only received a weak amount of sound. We could hear each other but had problems understanding each other.

Medium string:  I heard a tiny bit better then with the thin string, but it didn’t make a very big difference.

Large string: The sound was a bit better then the thiner strings we could understand each other almost every time. Even if it didn’t make a huge difference with the medium size string.

Data Table

	Amount of sound
Thin sowing string	weak
Medium-large string	medium weak
large string	high weak.

    D.  Analysis of Data:   Do you see any patterns?  Do you believe that your data shows accuracy and precision?

I think that my data shows that the volume increases just a little bit with thicker strings. I think that my data could have been a bit better if I had an appropriate instrument to measure decibels, sadly I didn’t. It would have given me precise numbers to compare my data with.

VI.         Concept Acquisition (CONCLUSION):  State the guiding question.  Present the relevant experimental results.  Discuss the relationship between variables.  What can you conclude regarding the guiding question?  Was your prediction correct?  If yes, explain.  If no, explain what you understand now about this investigation and how it taught you something new.

My guiding question was ‘ How does the thickness of string affect the sound that goes through it? My hypothesis was that it will travel better through thicker strings, and I was correct but I thought that the thickness would have affected sound much more. There , the difference of volume was very small.

VII.       Concept Application (FURTHER INQUIRY):    Examine the validity of your data and infer what you think the major causes of error may have been.  Propose methods of improvement.  For example, what modifications did you need to make or would make next time? Whatever happens in a test, think about all the reasons for your results.  Sometimes this thinking leads to a new hypothesis.  Write down these new hypotheses (predictions) or inquiries (questions) you may have here in this section.

My only mistake was that I should have been more precise with the data by using an instrument to measure data. But I could have made more interesting by using more types of strings as : wet strings, cold strings, warm strings, extremely thick strings, elastics and even maybe different types of cups! As I would think that wet strings would work better and that cups wouldn’t make a difference.

 

Helene Le Roux,

02/ 06 / 2012 ,

Mrs. Medenca ,

Science,

7 B

Tsunami

Each year earth earth is subject to a deadly natural diaster called tsunami, wich sadly kills thousands of people each year. By the end of this essay you will be able to answer questions as; What are tsunamis? Where do they form? What are their effects? And how to limit their hight death rates?

A tsunami is often defined as a large, often destructive, sea wave produced by a submarine earthquake, subsidence, or volcanic eruption. It occurs when under the sea, a plate tectonic slips under another plate tectonic, it creates a terrestrial disturbance called earthquake (but earthquakes can also be created by volcanic eruptions) .The earthquake will create one big wave, called tsunami, that will slowly go toward the beach. As they get closer to the beach, the tsunami will slow down, and get bigger because of all the smalls and fast waves that will have accumulated to the tsunami. The earthquakes can also be created by volcanic eruptions.

Knowing that tsunamis are created by earthquakes, it is obvious that they will mostly occur next to the ring of fire. The ring of fire is an extensive zone of volcanic and seismic activity that coincides roughly with the borders of the Pacific Ocean, and is a zone were about 90 percent of the world’s earthquakes occur. Tsunamis is one of the deadliest natural disaster. To give an example, in 2004 on the island of Sumatra a Tsunami killed about 320　000 people not counting the injuries, which was declare as the deadliest Tsunami of the year. It creates Big floodings everywhere in the area and many people die drowning. One other reason of the high death rate cause by the tsunamies is the debris that it accumulates, wich help the wave to break every thing on its way. Those debris are often large and small every day objects such as: tables, chairs, cars, trees, parts of houses, vases and corpse of all sorts, that slowly got picked up by the wave. It is so deadly, that even after the disaster happened it takes a lot of days for the water to leave. Meanwhile the water has become contaminated which creates new victims.

Sadly, Stunamis can’t be prevented and are beyond human control. But hopefully scientist created many ways of limiting it’s devastating effects. Mainly, the T.W.S (tsunami warning system), it "has the functions of monitoring seismological and tidal stations throughout the Pacific Basin to evaluate potentially tsunamigenic earthquakes and disseminating tsunami warning information". As the P.T.W.C (Pacifique Warning System Convention) is placed in Hawaii, it has the function of sending all of their information to other countries that have risks of having tsunamis. An other way to reduce the tsunamis and earthquakes, big death rate in a country, is for them to build building specially conceive to resist the those disaster’s huge power.

Also, most schools are instructed to teach their students of the steps to do in case a tsunami occurs. They also recommend adults to follow the advice of local emergency and law enforcement authorities. But one of the most simple and obvious way to know if an earthquake or tsunami is coming, is to look at the behavior of the animals surrounding them. It is known that animal are much more sensitive then humans are. If there is a sudden change in their behavior, there is a high probability that something is wrong. Even though, whith all those techniques of prevention, they are not as precise as we would like them to be and can never totally prevent the inevitable. There will always be some lives of animals and human, taken away. Because even if there is an evacuation not everybody can afford or are willing to leave. And even in the survivors, many people without insurance would have been victims, as they have lost their house and all of their goods.

In conclusion it has been seen that tsunamis are very deadly as they kill thousands of people each year. Also, they have a deep connection with earthquakes and both of those natural disasters are being studied a lot as people try to prevent their devastating effects. As while, for now, we only succeded to protect a few percentage of the population. The instruments and methods used to intercept a tsunami before it occurs are not very precise, as animals’ sixth sense was almost always right, would there be a way of using it in the future, to limit tsunamis high death rates?

　

Bibliography

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Dictionary.com. (n.d.). Retrieved june 2, 2012, from Dictionary: http://dictionary.reference.com/

Effects of Tsunamis. (n.d.). Retrieved june 2, 2012, from Universe Today: http://www.universetoday.com/39319/effects-of-tsunamis/

Ring of Fire. (n.d.). Retrieved june 2, 2012, from Webster: http://www.merriam-webster.com/dictionary/ring%20of%20fire

Tsunami Animation. (n.d.). Retrieved june 2, 2012, from Tsunami Safe: http://www.pep.bc.ca/tsunamis/causes_2.htm