My home-built seismographs
This page ©2012 Andrew Wylie all rights reserved
Remarkably, it turns out to be possible, with relatively little financial outlay, to build a seismograph capable of detecting earthquakes anywhere in the world, with a sensitivity that ensures a detection rate of one or two per week even in seismologically quiet locations such as the UK. Such a device detects either horizontal or vertical movement: professional devices usually incorporate three sensors to detect North-South, East-West, and up-down movement.
Many examples of amateur seismographs are described on the Web, including links to a July, 1979 Scientific American article describing a device built by Lehman that has become a standard for the mechanical basis of home builds. However, electronics and home computers have moved on enormously since 1979. If you are thinking of building one yourself, a good starting point is the Infiltec page.
I have been operating a Lehman seismograph for over a year now, and am currently designing a more sophisticated device. These pages describe my devices, but concentrate on the less conventional aspects, as the basic ideas are already well covered on other Web sites. Feel free to if you have any questions.