Tag Archives: recording earthquakes

Cheap seismometer using sound card and Amaseis – now running under Windows

After about a year and a half of messing around, I finally got this very cheap seismometer system working and displaying real-time data under both Windows and Linux (More on how to set up Linux later.) Educationally, it has great potential.

It consists of the sensor and an interface box. This interface is radically different from traditional digitizing methods. The earthquake signal, after being amplified, then modulates a fixed 5 KHz audio tone. That plugs into the microphone socket of a computer running three pieces of software under Windows (XP in the one shown here). They are, 1) the one I put together – “seismochop”, which retrieves the earthquake signal from the audio tone and converts it to serial data, 2) a virtual serial port package called com0com which acts as a relay, and 3) Amaseis – software that records and displays earthquake data. These three can be downloaded free.

This very cheap and rather unusual way to digitize an earthquake signal was inspired by my experience in ham radio, when AM transmitters were common. When I found the same principle (amplitude modulation of a carrier wave, or more correctly here, pulse amplitude modulation) used in “cheapchop“, even including the basic software, I was able to get it working.

Here is a screen shot of a local quake I recorded today. There’s a DOS window I brought to the foreground for the screen shot. That’s seismochop showing the data samples at about 11 samples per second. Continue reading

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Recording Earthquakes for Beginners – The Background Story

Background

In my search for educational projects that can engage a kid’s interest, I recently began looking into seismology (from Ancient Greek, “seismos”, an earthquake and “logia”, study of.)

Being a rather high-tech subject, I was skeptical of my chances of reducing it to something kids could do, but I gave it a shot anyway, since it’s very applicable here in Taiwan, where earthquakes average a couple a day. (You can see them on this website: http://www.cwb.gov.tw/eng/index.htm )

The goal was to come up with some kind of a detector; the simplest and cheapest design possible that a student could plug into a computer and record real earthquakes. Although still in progress I wanted to share what I’ve done so far as it’s a fascinating field and full of good, observable data that will give anyone a deeper understanding of the planet we live on. Continue reading

Posted in Electronics, Seismology | Tagged , , , , | 4 Comments