Rainwater may play an important role in the process that triggers earthquakes, according to new research.
Researchers identified the sources and fluxes of the geothermal fluids and mineral veins from the Southern Alps of New Zealand where the Pacific and Australian Plates collide along the Alpine Fault. From careful chemical analyses, they discovered that fluids from the mantle, the layer below Earth’s crust, and fluids derived from rainwater, are channelled up the Alpine Fault.
By calculating how much fluid is flowing through the fault zone at depth, the researchers showed for the first time that enough rainwater is present to promote earthquake rupture on this major plate boundary fault.
“Deep groundwaters may be important for the initiation of earthquakes as these fluids can weaken the fault zones by increasing pressures,” said lead researcher Catriona Menzies.