Deflecting Earthquakes The Way Ancient Romans Did It

A recent French study indicates that the ancient Romans may have figured out how to deal with earthquakes by simply deflecting the energy of the waves using structures that resemble metamaterials. These are materials which can manipulate waves (electromagnetic or otherwise) in ways which are normally deemed impossible, such as guiding light around an object using a special pattern.

In a 2012 study, the same researchers found that a pattern of 5 meter deep bore holes in the ground was effective at deflecting a significant part of artificially generated acoustic waves. One of the researchers, [Stéphane Brûlé], noticed on an aerial photograph of a Gallo-Roman theater near the town of Autun in central France that its pattern of pillars bore an uncanny resemblance to this earlier experiment: a series of concentric (semi) circles with the distance between the pillars (or holes) decreasing nearer the center.

Further research using archaeological data of this theater site confirmed that it did appear to match up the expected pattern if one would have aimed to design a structure that could successfully deflect the acoustic energy from an earthquake. This raises the interesting question of whether this was a deliberate design choice, or just coincidence.

Additional research on the Colosseum in Rome and various other amphitheaters did however turn up the same pattern, which makes it seem like a deliberate choice by the Roman builders over a long period of time. With this pattern apparently capable of protecting a structure from the destructive effects of the acoustic waves generated by an earthquake, the remaining question is whether they discovered this pattern over time by observing damage to buildings and decided to implement it in new buildings.

Although we’ll likely never get an answer to that question, this discovery can however lead to improvements to individual buildings today, as well as entire cities, that may protect them against earthquakes and save countless lives that way.

Build A Seismometer Out Of Plumbing Parts

For those outside the rocking and rolling of California’s tectonic plate, earthquakes probably don’t come up on a daily basis as a topic of conversation. Regardless, the instrument to measure them is called a seismometer, and it’s entirely possible to build one yourself. [Bob LeDoux] has shared his article on how to build a Fluid Mass Electrolytic Seismometer, and it’s an impressive piece of work.

This is an instrument which works very differently from the typical needle-and-graph type seen in the movies. Fluid is held in a sealed chamber, with a restricted orifice in the center of a tube. The fluid level is monitored at each side of the orifice. When motion occurs, fluid levels change at either side which allows seismic activity to be measured.

Hooked up to some basic analog electronics, in this form, the device only shows instantaneous activity. However, it would be trivial for the skilled maker to hook this up to a datalogging setup to enable measurements to be plotted and stored. The entire project can be built with simple hand tools and a basic PCB, making it highly accessible.

It’s not the first time we’ve seen a seismometer, either – the Raspberry Shake project is a distributed network of sensors running on the Raspberry Pi.