The connection between precipitation and earthquakes has come from a study of the Alpine Fault. Geological research suggests the fault has arisen through thousands of years of rainfall and snowfall.
The Alpine Fault is a geological fault running the length of New Zealand’s South Island, a boundary between the Pacific Plate and the Indo-Australian Plate. Earthquakes occur along the fault, with a major one taking place every 330 years.
The new research has come about after geologists traced the source of water flowing through New Zealand’s Alpine Fault. The earthquakes are triggered by underground fluids, which are the result of rainfall and snow melt-water. The fault is structured so that it traps large quantities of water.
Water helps to induce earthquakes by altering the strength of rock and counteracting the forces that hold two sides of a fault together. The assessment, according to Science News, was based on water-deposited minerals in rocks, the relative abundance of helium in nearby hot springs and the various oxygen and hydrogen isotopes that made up the water.
It is hoped by tracking water activity, scientists will be able to predict earthquakes, with greater accuracy, further in advance of the tremors happening. Moreover, the results may inform about other faults around the world. In addition to the build-up of water naturally from precipitation, the Earth’s depths also hold watery waste such as municipal wastewater and, increasingly, used fracking fluid trucked in from faraway wells. These can cause pressure to build up, and quakes can be triggered as a result of the greater pressure.
For example, it has been noted that the act of pumping wastewater underground has affected parts of Oklahoma. Here considerable quantities of water left over from oil and gas extraction could have led to earthquakes in certain regions of state since 2008.
The research was carried out at the University of Southampton, U.K. The research is published in the journal Earth and Planetary Sciences Letters (“The fluid budget of a continental plate boundary fault: Quantification from the Alpine Fault, New Zealand.”)
