Our hypothesis- the seismograph will pick up smaller vibrations the further away we drop the ten pound weight, adding a half inch thick peice of styrofoam will dampen these vabratins even more.

 

Background research

Seismographs are instruments that keep track of the way the earth shakes during an earthquake. They are put in the ground all over the world and are collectively called a seismographic network. Seismographs  are built with a seismometer  on the inside which could be a pendulum or something like a rock attached to a spring. The first version of a seismograph was called a seismoscope; it was created by a Chinese philosopher named Chang Heng in A.D 123. But it did not record earthquakes like a seismograph the seismoscope told if there was an earthquake happening. It was developed in 1890. A seismogram is the recording created by the seismograph in the area the earthquake occurred. On a seismogram there are two axises, the horizontal axis is measured in seconds and the vertical axis is measured in millimeters for the shaking. When there is no earthquake it is a straight line other than tiny wiggles caused by local disturbances. seismometers used in modern times are normally electrical. Meaning that instead of utilizing a pen and a drum it uses relative motion between the weight and the frame that creates an electrical voltage which is recorded on the computer. If you change the way the spring, weight and frame, the seismometer will be able to record motions in all directions. Seismometers can also normally take note of ground motions caused by a large variety of natural phenomena like trees blowing in the wind, and man made phenomena like cars and trucks on the highway. plate tectonics are large plates of rock which ocasionally hit eachother which causes earthquakes.

 

controlled variable(s)- weight, height height of drop, paper speed.

manipulated variable(s)-what we place the siesmograph on, distance.

responding variable(s)-seismogram

First we set up the seismograph on the end of a 6 ft by 29.5 in table. Next we marked 1 ft, 2 ft, and 3 ft on the table from the edge of the seismograph. Third we started to pull the paper through the seismograph with a drill rotating at low speeds. With the seismogreaph recording, we then dropped a 10 pound weight at the 1 foot mark from a height of 8 in above the table. We recorded the impact of the weight on the table with the siesmogram. Once the shaking stopped we reset the sharpie attached to the seismograph because the impact somtimes shifted the position of the pen from the middle to the edge. This was repeated 3 times to get an accurate result. The proces was repeated at the 2 ft and 3 ft marks.

A peice of styrofoam a half inch thick was then placed uner the the body of the seismograph. The process of dropping the 10 pound weight from 8 in above the table at the 1 ft, 2 ft, and 3 ft marks was then repeated and the results were collected and labled.

#1 at 1 ft (test, table)

1. maximum shift of sharpie: 1.1 cm, maximum amplitude: 1.1 cm

2. maximum shift of sharpie: 1.0 cm, maximum amplitude: 0.6 cm

3. there was interferance

4. maximum shift of sharpie: 0.5 cm, maximum amplitude: 0.5 cm

#2 at 1 ft (table)

1. maximum shift of sharpie: 0.9 cm, maximum amplitude: 0.6 cm

2. maximum shift of sharpie: 0.7 cm, maximum amplitude: 0.6 cm

3. maximum shift of sharpie: 0.55 cm, maximum amplitude: 0.55 cm

#1 at 2 ft (test, table)

1. there was interferance

2. maximum shift of sharpie: 0.7 cm, maximum amplitude: 0.7 cm

3. maximum shift of sharpie: 1.5 cm, maximum amplitude: 1.3 cm

4.  maximum shift of sharpie: 1.2 cm, maximum amplitude: 0.5 cm

#2 at 2 ft (table)

1. maximum shift of sharpie: 0.2 cm, maximum amplitude: 0.4 cm

2. maximum shift of sharpie: 0.5 cm, maximum amplitude: 0.45 cm

3. maximum shift of sharpie: 1.5 cm, maximum amplitude: 0.9 cm

#1 at 3 ft (test, table)

1. maximum shift of sharpie: 0.6 cm, maximum amplitude: 0.4 cm

2. maximum shift of sharpie: 0.2 cm, maximum amplitude: 0.3 cm

3. maximum shift of sharpie: 0.8 cm, maximum amplitude: 0.65 cm

#2 at 3 ft (table)

1. maximum shift of sharpie: 0.25 cm, maximum amplitude: 0.5 cm

2. maximum shift of sharpie: 0.4 cm, maximum amplitude: 0.3 cm

3. maximum shift of sharpie: 0.05 cm, maximum amplitude: 0.6 cm

#1 at 1 ft (test, styrofoam)

1. maximum shift of sharpie: 0.1 cm, maximum amplitude: 0.4 cm

2. maximum shift of sharpie: 0.7 cm, maximum amplitude: 0.9 cm

3. maximum shift of sharpie: 0.15 cm, maximum amplitude: 0.4 cm

#2 at 1 ft (styrofoam)

1. maximum shift of sharpie: 0.75 cm, maximum amplitude: 0.5 cm

2. maximum shift of sharpie: 0.65 cm, maximum amplitude: 0.8 cm

3. maximum shift of sharpie: 0.1 cm, maximum amplitude: 0.4 cm

#1 at 2 ft (test, styrofoam)

1. maximum shift of sharpie: 0.5 cm, maximum amplitude: 0.4 cm

2. maximum shift of sharpie: 0.2 cm, maximum amplitude: 0.6 cm

3. maximum shift of sharpie: 0.05 cm, maximum amplitude: 0.7 cm

#2 at 2 ft (styrofoam)

1. maximum shift of sharpie: 0.15 cm, maximum amplitude: 0.7 cm

2. maximum shift of sharpie: 0.4 cm, maximum amplitude: 0.3 cm

3. maximum shift of sharpie: 0.65 cm, maximum amplitude: 0.5 cm

#1 at 3 ft (test, styrofoam)

1. maximum shift of sharpie: 0.7 cm, maximum amplitude: 0.2 cm

2. maximum shift of sharpie: 1.25 cm, maximum amplitude: 0.45 cm

3. maximum shift of sharpie: 1.2 cm, maximum amplitude: 0.5 cm

#2 at 3 ft (styrofoam)

1. maximum shift of sharpie: 1.3 cm, maximum amplitude: 0.4 cm

2. maximum shift of sharpie: 1.2 cm, maximum amplitude: 0.9 cm

3. maximum shift of sharpie: 1.3 cm, maximum amplitude: 0.25 cm

Shift of Sharpie
Tabletop 
The average shift of the sharpie on the tabletop was 0.79 cm at one foot, 0.93 cm at 2 feet, and 0.38 cm at 3 feet. It is not clear why
the average shift of the sharpie at two feet increased. The two foot mark is in the center of the table and is not supported directly by
the table legs. This may have been a reason for an increased average shift of the sharpie at two feet. In general, the trend shows
that the vibration decreases the further the weight is dropped from the seismograph.
Tabletop with 0.5 inch styrofoam
The average shift of the sharpie on the tabletop with 0.5 inches of styrofoam insulation was 0.41 cm at one foot, 0.33 cm at 2 feet,
and 1.16 cm at 3 feet. It is not clear why at three feet we repeatedly measured large shifts in the sharpie. We believe the high values
had something to do with the structure of the table or the operation of the seismograph. Future testing would repeat this series of
tests to confirm results and focus more on what could have cause them.
General Trends between Tabletop and Tabletop with 0.5 inch Styrofoam
At one foot the average shift of the sharpie is 0.79 cm on the tabletop. With the styrofoam insulation the average shift of the sharpie
at one foot is 0.41 cm. This is a 0.38 cm decrease in the average shift of the sharpie when styrofoam is used.
At two feet the average shift of the sharpie is 0.93 cm on the tabletop. With the styrofoam insulation the average shift of the sharpie
at two feet is 0.33 cm. This is a 0.60 cm decrease in the average shift of the sharpie when styrofoam is used.
At three feet the average shift of the sharpie is 0.38 cm on the tabletop. With the styrofoam insulation the average shift of the sharpie
at three feet is 1.16 cm. This is a 0.78 cm increase in the average shift of the sharpie when styrofoam is used. This result does not
align with our hypothesis.

Maximum Amplitude
Tabletop 
The average maximum amplitude on the tabletop was 0.66 cm at one foot, 0.71 cm at 2 feet, and 0.46 cm at 3 feet. It is not clear why
the average maximum amplitude at two feet increased. The two foot mark is in the center of the table and is not supported directly by
the table legs. This may have been a reason for an increased average maximum amplitude at two feet. In general, the trend shows
that the vibration decreases the further the weight is dropped from the seismograph.
Tabletop with 0.5 inch Styrofoam (Figure 4)
The average maximum amplitude on the tabletop with 0.5 inches of styrofoam insulation was 0.57 cm at one foot, 0.53 cm at 2 feet,
and .45 cm at 3 feet. These results align with our hypothesis.
General Trends between Tabletop and Tabletop with 0.5 inch Styrofoam
At one foot the average maximum amplitude is 0.66 cm on the tabletop. With the styrofoam insulation the average maximum
amplitude at one foot is 0.57 cm. This is a 0.09 cm decrease in the average maximum amplitude when styrofoam is used.
At two feet the average maximum amplitude is 0.71 cm on the tabletop. With the styrofoam insulation the average maximum
amplitude at two feet is 0.53 cm. This is a 0.18 cm decrease in the average maximum amplitude when styrofoam is used.
At three feet the average maximum amplitude is 0.46 cm on the tabletop. With the styrofoam insulation the average shift of the
sharpie at three feet is 0.45 cm. This is a 0.01 cm decrease in the average maximum amplitude when styrofoam is used.

In general our hypithisys seems to be corresct. One of the key differances between our hypothesis and our results was the shift of the sharpie at 3 feet with styrofoam. We belive this was caused by the build and oporation of the seismograph as we had to adjust the wire holding the beam up to 2 times during testing. We would recommend re-testing the vibrations at 3 feet with styrofoam.

The information that we have gathered can be useful for future projects, one of them being seeing which materials will dampen vibrations the most. 

Our results show that the further someone is from the source of vibation the weaker the vibrations will feel. They also show that using certian materials could dampen the impact of the vibrations. This can be aplied to buildings in areas like japan which are very earthquake-prone places.

It has occurred to us that the following may be sources of error:

1. The desighn and constuction of the seismograpgh

- Not including a weight attached to the beam may have caused the sharpie to shift

2. Accidentaly touching table during testing

3. Holding wood block while testing

1.      US National Science Foundation, SAGE, Seismological Facility for the Advancement of Geoscience, What is a seismograph and how does it work?

a.      https://www.iris.edu/hq/programs/epo/life_of_a_seismologist/its_instrumental/what_is_a_seismograph_and_how_does_it_work#:~:text=A%20seismograph%20is%20a%20device,coupled%20with%20a%20recording%20system.

2.      Wikipedia, Plate tectonics.

a.      https://en.wikipedia.org/wiki/Plate_tectonics

3.      Science Buddies

a.      https://www.sciencebuddies.org/science-fair-projects/project-ideas/Geo_p017/geology/make-your-own-seismograph

We would like to aknowledge the help we recieved from our homeroom teacher, Mr. Tolmlinson, Blythe's dad Mr .Hardy,  and each other.