Snakes sensitive to earthquake precusors

[Mokele]

Snakes don't have the luxury of minimizing their contact with the ground.

 

Well, they can climb very well, but also, the foot-spread thing seems to be concerned with the voltage between two isolated points, rather than along a continuous surface of contact.

 

Has anybody been in the field and had the opportunity to observe snake reactions to nearby lightning strikes?

 

Nope - if you're close enough to the strike to see it's effect on any snakes nearby, you're probably too close to the lightning for safety. Nobody really does fieldwork in lightning storms unless that's specifically what they're looking at, and even then, remote sensing is preferred since, well, you can't publish your results if you're dead.

 

Mokele

[FrankM]

Well, they can climb very well, but also, the foot-spread thing seems to be concerned with the voltage between two isolated points, rather than along a continuous surface of contact.

 

The lightning safety article stated that you "should not lie down" as this puts you in continuous surface contact, thus you have a greater change to be in contact with "potential points" that are high enough to break-down your resistance, thus creating a damaging current flow.

 

It is simple Ohm's law, a small current across a high resistance results in a high potential difference.

 

This snake crawled across a circuit board until he extended across a potential that exceeded his biological resistance. The individual that took the picture and replaced the board did not note which board potential zapped the snake. There were two voltage sources to the board, +42 volt and +5 volts.

[Norman Albers]

One day, over beers, I'll tell you about the snake who kept me company, above in the pecky cedar wall, as I tuned the upright piano. No, you cannot make up stuff this good! OK, back to science, this snake episode was from a relatively high-current supply.

[FrankM]

OK, back to science, this snake episode was from a relatively high-current supply.

The title of the .jpg and the character of the circuit board are clues. That was 20+ year old technology and it was a telephone circuit loop control card. The big gold plated contacts are a giveaway to the era. Either way, the +5 or the +42 volts were relatively high current sources. It is not known which one did the major zapping. I believe the individual identified the victim as a "rat snake".

 

Why even use snakes? Get some tanks of knifefish, and run a nice big copper wire from a point embedded into the ground to the water of their tank. We know they can sense electricity (they use it to communicate), and they're far more sensitive thans snakes could ever be. Hell, small sharks aren't even that hard to raise, and they can detect the beating heart of their prey from several meters away.

Although video cameras can be used to observe critter reactions, there is a problem of constantly monitoring them visually. The Chinese did not note the use of any kind of motion detector, thus when do you watch? The suggestion to use an electro-sensitive fish has the same problem, how do you determine the difference between normal movement and that which results from an electrical current? Do you have to watch 24/7?

 

Putting a couple of wires in the ground sounds good but there is a problem, the direction of the "current vector" from a seismic induced current. For maximum potential the contacts have to be in line with the current vector, if they were at 90 degrees there would be little or no current differential, even though an event created significant current flow. The current will expand outward from the seismic source. For each small segment of surface area the current vectors will be essentially parallel but another segment that is a quarter circle away from the source will have current vectors that are different by 90 degrees. Unlike the "strike point" for lightning, the seismic induced currents do not come from a point source, they come from an extended stress zone which can be kilometers long. Every monitoring station would have to have a minimum of 2 pairs of contacts at 90 degrees.

 

Seismic events are not the only sources that create ground currents. Sunspot activity is one outside source and the intensity of ground currents generated by those events depends upon the earth-sun orientation. Additionally, not all sunspots are created equal and their effects on the earth are not uniform.

 

If ground currents are the source for snakes agitation preceding earthquakes, it would be nice to know exactly what potentials are necessary to get their attention, we could then use that as a threshold.

[Norman Albers]

Are ground currents always involved? What about vertical static electric fields?

[Mokele]

If ground currents are the source for snakes agitation preceding earthquakes, it would be nice to know exactly what potentials are necessary to get their attention, we could then use that as a threshold.

 

It just seems like an unnecessary step. Why waste time looking for animals to respond and determining how when you can no doubt design instruments with far superior sensitivity, range, and recording capabilities, which won't be nearly as prone to error as the snakes? Hell, when you factor in the costs of keeping the snakes and buying them and setting up cages, it'd probably be cheaper to use instrumentation, too.

 

Mokele

[ashley_702]

Before an earthquake occurs, how do animals know, and what causes them to react?

[FrankM]

On the amateur science experiments thread I posted a few of my observations where I subjected earthworms to AC and DC electric currents.

 

http://www.scienceforums.net/forum/showthread.php?t=26312

 

An image of an earthworm responding to an earthquake is available at a USGS site.

 

http://folkworm.ceri.memphis.edu/ew-doc/