Research led by the Open University's Dr Rachel Grant, and Dr Friedemann Freund of NASA, suggests that animals may sense chemical changes in groundwater when an earthquake is about to strike.
The research comes out of Dr Grant's observations in 2009, when she was studying breeding toads in the region outside the Italian city of L'Aquila as part of her OU PhD project. She noticed almost all the toads left the site several days before a devastating earthquake struck on 6 April.
“One day there were no toads,” she said. “I was actually very annoyed. I thought my research was all going down the drain. And the earthquake happened, and then they all started coming back the day after.”
When Dr Grant and OU amphibian specialist Professor Tim Halliday published a report in the Journal of Zoology they were contacted by scientists at the US space agency NASA who were studying chemical changes in rocks under extreme stress.
This led to further research published this month in the International Journal of Environmental Research and Public Health.
It says laboratory-based tests have now shown that the Earth's crust could have directly affected the chemistry of the water that the toads were living and breeding in.
When rocks are under very high levels of stress they release charged particles, starting a chemical chain of events which can lead to a build up of toxins in groundwater.
Charged particles in the air – known as ions – are known to cause headaches and nausea in humans.
The scientists say their theory needs testing, but they hope it will eventually contribute to more accurate forecasting of earthquakes.
