Hi All. I have a little bit of the owl in me tonight. I go through these spells where I sleep very little. There are times I don’t sleep at all. It appears that this morning is one of those times.

Anyway I found this interesting little article and though I would share it with you. Take Care…Don in creepy town

A recent noble gas study by CIG's Kennedy and Yousif Kharaka may also mean a reexamination of existing models, in this case, models that explain the presence of high-pressure fluids in fault zones. High-pressure liquids or gases can weaken faults, making them even more prone to quakes. One of the most infamous examples is the San Andreas fault in California, where the North American and Pacific plates meet.

Scientists suspect that high-pressure fluids act as lubricants, making it easier for rocks in a fault zone like the San Andreas to be displaced. However, they need to know much more about these fluids, starting with the basic question: where do they come from? Two competing models attempt an answer. One says high-pressure fluids originate in the crust, seep into the fault zone and become trapped by mineral reactions. The other says these fluids originate in the mantle and get siphoned into the fault zone through the ductile base of the crust.

To test these models, Kennedy and Kharaka measured high-pressure fluids along the San Andreas fault for ratios of helium isotopes. To their surprise, they found ratios of the exceedingly rare helium-3 (helium with only one neutron) to common helium-4 (two neutrons) that were hundreds of times higher than the helium-3 to helium-4 ratios typically found in crustal fluids.

"Some of this fluid could have come only from the mantle," says Kennedy who believes that as fluids move upward from the mantle, helium-3 becomes increasingly diluted by the helium-4 that is common to the crust. This makes it difficult to determine the degree to which high-pressure mantle fluids contribute to the weakness of the San Andreas Fault, but the effect is thought to be large. The Kennedy and Kharaka study also raises the possibility that mantle fluid is flowing into the San Andreas Fault from great distances away.

• Helium 3