Rachel Grant of the Open University and several other researchers have attempted to solve an age-old problem. The multiple effect of O- ions on rock, air ionisation and water, as they leave their silicate home and become "positive holes" has created myths about animals and others for thousands of years. The positive hole becomes what physicists term h* (hydrogen) and a free electron, e,. This group have concentrated on ground water, as it is oxidised by these loose cannons! The spur to the work seems to have been the much-reported Italian M6.3 earthquake on April 6th 2009. A toad breeding lake emptied a few days before the quake and was revisited by its occupants after a series of aftershocks.
Grant's list of potential warnings for animals consists of:
(i) Low to ultralow frequency electromagnetic emissions from the ground,
(ii) Luminous phenomena, often called earthquake lights, prior to many seismic events, recorded at the time of the toad phenomenon in L'Aquila, at up to 50km from the epicentre.
(iii) Enhanced infrared emission from the epicentral region as seen in satellite images,
(iv) Changes in the atmosphere near the ground and at altitudes up to about 12,000 m,
(v) Perturbations in the ionosphere 100-600 km above the Earth's surface,
(vi) Changes in the ocean water and ground or spring water chemistry.
These are all purported to be the result of the positive holes, which carry out a process of electrification (electron release.) In the ground water researched thoroughly in this article, the primary result is the formation of hydrogen peroxide, which is a chemical destroyed by animals' blood defences Organic compounds in water would also be oxidised. Examination of spring and ground waters after the Izmit and Lake Garda earthquakes have revealed fluorescence spectra with very high intensity. This illustrates clearly that organic compounds dissolved in these waters have been partially oxidised. The identity of these compounds is critical, but a related huge release of CO2 from the ground in ,for example, Gujarat, implies that some of the compounds must contain carbon.
The animal behaviour is the main point of the research. Snakes (Haicheng earthquake)and toads (L'Aquila) are the examples given. Crabs also leave the water. Fish have also been recorded leaving the depths, including the "indicator species", Trachipterus (ribbon fish) and Regalecus (oar-fish). These two are often seen before earthquakes.
Here is the evidence of the toads leaving their precious breeding site in Italy:
Explanations could vary, but the association is obvious. Another graph proves heavy rain fell at the time of leaving, meaning the lack of water cannot have influenced the toads. The explanation of the animals' receptors detecting a phenomenon is part of the research here. As Amphibia, toads are much more receptive to water change than snakes or possibly even fish. They rely on water for breathing through the skin and therefore have to be permeable to electrolytes in the water. Low pH and the threatening hydrogen peroxide are obvious candidates to make them leave the water, but some oxidised organic matter contains neurotoxins and high cation (eg. H+ K+, Mg2+ and Ca2+) concentrations upset an animal's sodium balance.
In conclusion, the authors posit that the animals must be affected by the changes in their watery environment. Land animals, while often affected by natural disasters have less input than a toad detecting many chemical and other disturbances. So it is sensible to presume that if we would like earthquake warning, we need to quickly develop complex instrumentation, or go to the toad, thou sluggard!