Bicycle Seismograph Measures The Streets

Riding the streets of the Netherlands on a bicycle is a silky-smooth experience compared to doing the same on those of Germany. So says [Kati Hyyppä], who made the move with her trusty Dutch bike. The experience led her to record the uneven cobblestones and broken asphalt of the German roads on a home-made seismograph, a paper chart recorder driven by the bike’s motion and recorded upon by a pen free to vibrate as it passed over any bumps.

The resulting instrument is a wooden frame with a ballpoint pen mounted in a sliding holder weighted with some washers and kept under some tension with elastic bands. The paper roll is driven from the motion of the bike by the drive from a mechanical speedometer feeding a set of FischerTechnik gears, and the whole unit is suspended from the crossbar.

You can see it in action in the video below the break, and if you would like to build one yourself she has put the project up on Instructables as well as posting the description linked above.

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Earthquake detector could have helped during quakepocalypse

[Andrea] built a seismic wave detector that warns of a possible impending earthquake. Because P waves travel much faster than the “make everything shake” S waves, building a device that detects P waves serves as an early warning system that alerts building occupants to go under a door frame. [Andrea]’s build detects these fast-moving P waves and only took an hour to make.

Last August, those of us on the east coast of the US had to live through Quakepocalypse, a magnitude 5.9 earthquake centered around Middle of Nowhere, Virginia. For those of us who have decided to stay, rebuild, and put our garden chairs upright again (so brave…), [Andrea]’s build could have been very useful.

The mechanics of the build is very simple: a pair of springs and levers are electrically wired together so that whenever there’s a sudden shock, a buzzer goes off. It’s very similar to an ancient Chinese earthquake detector that detects P waves by dropping a ball into a frog’s mouth.

While we’re not sure if a few of [Andrea]’s devices would be needed to detect P waves coming in off-axis, the build is simple enough to build dozens of them. Check out the video of the build in action after the break here.