Earthquake Detector

I grew up in California, and have had the fortune of experiencing every major earthquake in this state since I was born. I love them and fear them at the same time! Earthquakes are exciting, but also mysterious. Living in such a seismically active state, there are earthquakes all the time that most people don't even feel! That is why I decided to build this Earthquake Detector

Step 1: Tools and Materials

(x2) 741 OpAmps (Radioshack Catalog #: 276-007)
(x1) 9V Relay (Radioshack Catalog #: 275-005)
(xvar) jumper wires (Radioshack Catalog #: 276-102)
(x2) Heavy duty 9V battery clips (Radioshack Catalog #: 270-324)
(x2) 9V batteries (Radioshack Catalog #: 23-866)
(x1) Prototyping PCB (Radioshack Catalog #: 276-170)
(x1) Piezo Buzzer (Radioshack Catalog #: 273-080)
(x1) 5K Ohm Potentiometer (Radioshack Catalog #: 271-1714)
(x1) Potentiometer cap (Radioshack Catalog #: 274-415)
(x1) 470 Ohm Resistor (Radioshack Catalog #: 271-1317)
(x1) 3" diameter acrylic tube
(x1) Magnet (Radioshack Catalog #: 64-1888)
(xvar) lamp-pull ball-chain


Tools:
Solder
Soldering Iron
Wire Snips
Hot Glue Gun

I used a laser cutter to make my own personal enclosure, but one could easily modify a pre-made project enclosure to suit the needs of this project.

Comments

[David97]

I live in Christchurch, New Zealand. I wonder how sensitave this would be as we have just had an earthquake that caused us to loose water for 2 weeks and power for a month and killed 300. We are still getting aftershocks a day after 2 years!

[Wareneutron]

nice work!

[Attmos]

Every home in California should have one. ;)

[static]

While not exactly the sme Forest Mimms II had a similar project in Science Probe. Simply used a wound coil, and had mineral oil to dampen the magnet movement. Also had an output that could go to a chart recorder or PC recorder software

[Light_Lab]

If you want to focus on earthquake motions you probably want to detect the vertically moving primary waves. These have a frequency around 0.1 to 1 Hz.
http://eqseis.geosc.psu.edu/~cammon/HTML/Classes/IntroQuakes/Notes/seismometers.html
The easiest way to do this is to have a fairly heavy weight on the end of a coil spring. This will increase the sensitivity to lower frequencies. The other thing to do is to have some sort of damper like a paddle in oil. This might reduce non-earthquake vibration detection like trucks and people walking around.
You could do some of this electronically with filters.

[pfred2]

We had an earthquake here last year. It sucked! When the Earth is moving there really isn't anything anyone can do about it now is there? It was really more like a wave here. I saw my garage floor come up, then sine wave fashion go back down again. I thought I was flipping out. I mean we're not known for having earthquakes in these parts. In any event the feeling of helplessness I felt was palpable. I like my terra firma!

[audreyobscura]

Agreed. I have been on the west coast my whole life, and have grown accustomed to earthquakes, I have noticed that my best earthquake detector is my dog - she goes and sits in my closet maybe 20 minutes before there is one.

[WorldOfTanks]

couldnt you use a reed switch instead?

[ppsailor]

Hi!
Years ago I built a motion sensor similar to the samples we.
Can you please show the circuit diagram clearer? FULL
To compare it with mine
THANKS

[audreyobscura]

Circuit Diagram is now the main image for step 4.

[ferjanyen]

Hi, a very nice project!!! I live in Spain, Torrevieja,(an earthquake aerea) and I would live to make this project but I would also like to see the circuit diagram for this project,

[audreyobscura]

Circuit Diagram is now the main image for step 4.

[devalpha_1]

Great Idea. Kindly provide the circuit diagram.

[audreyobscura]

Circuit Diagram is now the main image for step 4.

[TechGnostic]

My first Earthquake experience was when I soaking was in the tub. I hope that image doesn't violate the "be nice" policy : ))

Anyway, I was just lounging and enjoying the feel of the water when I noticed the water started to slowly sway side to side! I wasn't moving at all, and I couldn't understand what was going on at first. Since I live in a tectonically "stable" part of the planet, it took a few seconds to hit me that it was an Earthquake - a very mild one.

Since then I've always wanted to build a detector / data collector.

Not sure if you have this already - here's a link the the USGS Earthquakes data pages

http://earthquake.usgs.gov/earthquakes/


Thanks for some ideas on How-To.

[AtomRat]

It's still great, can b used 4 many other things too! Ill still make one

[AtomRat]

I have seen a different version of these where you can use the piezo buzzer as a mic to pick up the tremors, if you are interested, tell me and I'll find it for you, its an ebook ( like a '..For The Evil Genius' ebook collection. ) In the meantime, this one is much more simple, and I'll give it a go as I do need one at the moment for tremors that I swear can continue for days.

Is this kind of just a motion sensor 'switch', rather than a detector? Can you get a reading from this to log the strength of a quake / tremor, or is the relay just turning on an earthquake alarm for nearby people.

[audreyobscura]

It is more of an alarm. As long as the magnet is sweeping over the relay (triggered by the earth's motion), the buzzer will sound.