The Scientists have discovered natural deep earth pumps and that contributes to earth quakes. The discovery was made by examining one millimeter sized cubes of exposed rock in Alice Springs, which was deformed around 320 million years ago during a period of natural mountain formation. The evidence is described in a paper published in the latest edition of Nature entitled Creep cavitation can establish a dynamic granular fluid pump in ductile shear zones.
Research leader Dr Florian Fusseis, from the University of Western Australia, said that the discovery could provide valuable information in understanding how earthquakes are formed. Dr Fusseis said, While we understand reasonably well why earthquakes happen in general, due to stress build-up caused by motions of tectonic plates, the triggering of earthquakes is much more complex.
The process, called creep cavitation, involves fluid being pumped through pores in deformed rock in mid-crustal sheer zones, which are approximately 15 km below the Earth’s surface. The fluid transfer through the middle crust also plays a key role in tectonic plate movement and mantle degassing.
The discovery was made possible through the use of high-resolution Synchrotron X-ray tomographic, scanning electron microscope observations at the nanoscale and advanced visualisation using iVEC in Western Australia.
To understand the ‘where’ and ‘when’ of earthquakes, the ‘how’ needs to be understood first. We know that earthquakes nucleate by failure on a small part of a shear zone. Dr Fusseis said that while their sample did not record an earthquake it gave them an insight into the structures that could be very small and localized precursors of seismic failure planes.