If I were to mention the name L'Aquila, how many of you would recognise it? It's only a month since this town in central Italy made headlines around the world when it was devastated by an earthquake which killed more than 280 people, and yet, despite the fact many of the survivors are still living in tents in dire circumstances, the only recent mention of it in the media has been as a result of the Pope's visit, more than three weeks after the event.
As with most disasters, the actual catastrophic event grabs the public's attention far more than the protracted aftermath.
It is certain that the death toll in this, and indeed in any previous fatal earthquake, could have been reduced enormously if a reliable method of forecasting earthquakes existed.
Indeed, an Italian technician, Giampaolo Giuliani, claimed to have predicted the earthquake in L'Aquila, based on his observations of release of a gaseous element called radon in the vicinity of the town.
When he tried to warn the townspeople of an impending earthquake, he was reported to the police for "spreading alarm".
Whether he was right, or made a lucky guess, the basis of his method, radon, has connections to New Zealand - for this element was discovered by none other than our own Ernest Rutherford. Or was it?
Radon is a radioactive gas which, owing to its position near the bottom of the Periodic Table of the elements, is more than eight times as dense as air.
It exists on Earth as a product of the radioactive decay of radium, which is itself formed from decay of both uranium and thorium.
The longest-lived isotope of radon has a half life of about four days, so an atom of radon doesn't hang around for long.
A quick trawl around the web might convince you that the discoverer of radon was one Friedrich Ernst Dorn, in 1900.
However, controversy surrounds this, and a recent paper in a journal devoted to the history of chemistry (yes, there is such a thing) unequivocally states Rutherford to be the "true discoverer" of radon; his original work predates Dorn's, and Rutherford was the first to propose radon as a new element.
Given the fact that radon is short-lived, you might think it's pretty harmless, but that's not the case, although it took until the mid-1980s for this to be realised.
Because both uranium and thorium occur naturally, houses that are either constructed of stone, or built in areas containing high levels of uranium or thorium minerals, can contain potentially dangerous levels of radon which, because of its weight, tends to accumulate in the basement.
The irony here is that the better insulated the house, the greater the danger, as the airflow through the house is less.
However, given that the average Dunedin house could generally double as a commercial wind tunnel, it's not going to be too much of a problem here.
So back to the Italian earthquake. It is known that seismic events can cause the release of radon from the earth's crust, but so, too, can other phenomena.
This makes Giuliani's method of forecasting uncertain at best, and we still await a fail-safe method of earthquake prediction.
Given that the largest recorded earthquake in New Zealand (magnitude 8.2) occurred in Wellington in 1855, one would imagine that the inhabitants of the capital would be especially keen on some advance warning of the next big one, because it's a matter of when, not if.
- Allan Blackman
