Design a Seismograph Lab

Guiding Question:

Can you design and build a seismograph that can record the movements of simulated earthquakes?

Hypothesis:

We should be able to build a seismograph that works, but my hypothesis is that it’s going to be difficult to build one that works for every kind of earthquake, whether it’s tiny, moderate, or huge.

Materials:

- Chair

- Two wooden boards

- nails

- Two wires

- Two strings

- Weights

- Tape

- Book

- Paper

- Pencil case

- A pen

Procedure:

1. First, nail the two boards together to create a 90 degree angle.
2. Next, hang a string from the edge of the boards and attach a pen to it.
3. Add two weights to the pen so that it doesn’t dangle all over the place.
4. Put that whole contraption on top of a chair to keep the boards in place. To make it even more stable, rest it on top of the pencil case.
5. Put the strings and wires around the legs of the chair and attach them to the pen so that it is kept firmly in one spot.
6. Put a clean sheet of paper on a book under the pen so that the tip of the pen is just resting on the paper. The book represents any seismic activity, so in order to make a test, shake the book but move it in a certain direction at the same time. On the paper, there should be a long squiggly line, which is the seismogram.

Data Analysis:

Although I wasn’t there for the first part of the experiment, even while I was there, there were a lot of alterations that had to be made to the original design to make it work. Bigger earthquakes were supposed to cause bigger lines on the paper, but all that they seemed to do was make a bunch of random scribbles on the page. Eventually we realized that we were doing it wrong. Instead of shaking the book, we shook the chair, which was saying that the seismograph shakes, not the earthquake. Once our seismograph finally worked properly, we were able to easily see that if the earthquake is big, then the lines are really big and really close together. If there is no earthquake at all but the seismograph is still functioning, then it just draws a straight line.

Conclusion:

I liked this lab because it taught us about seismographs and about measuring earthquakes, and we were actually able to pretend there was an earthquake and measure it. I learned that the smaller lines on the seismograms meant the earthquake was really small, while bigger lines and bigger differences between them meant that the earthquake was very large. I also learned something about doing scientific labs in general, because we had to do so many tests. Even if you don’t figure out how to do the experiment right away, there’s always something that can be changed to make it function more properly. We tried many different ways of keeping the pen in one place at exactly the right level, but only the last one worked.

Further Inquiry:

If I were to do this lab again I would try to make a couple of changes to the design (seeing as I wasn’t the one to actually design it). First of all, I would try to create a long roll of paper kind of like toilet paper, so that you wouldn’t have to keep changing sheets of paper when there’s an earthquake and so that you can measure more than like 4 seconds of the earthquake. I think the wooden structure that we had was also kind of unnecessary, because by the time that we attached the strings and the wires to the chair and the pen at the same time, the wooden structure was doing basically nothing except keeping the chair in place. There are also probably a lot of other alternatives that are easier to keep the chair in place. If we have efficient seismographs then they would help the rest of the world by helping us understand the natural disasters around us and by helping us compare earthquakes all around the world so that it’s clear where most earthquakes occur, or where the faults of the world are.