The secret to starting subduction is ... subduction

Caroline Eakin, ANU

The Earth's biggest earthquakes and most explosive volcanoes occur at subduction zones" where a tectonic plate (the seafloor itself) sinks bank into the Earth's interior.

"Subduction zones are a vital ingredient for plate tectonics, and thus for maintaining a habitable planet, but how they originate is one of the biggest unsolved puzzles in modern Earth Science."

We've been able to compile 100 million years of existing evidence for Subduction Zone Initiation (SZI). One of the biggest things this showed was that subduction breeds subduction. Truly spontaneous subduction in "pristine" places is practically unheard of.

The research - led by the Centre for Earth Evolution and Dynamics at the University of Olso - was undertaken by a team of 14 early-career researchers from around the world.

It has resulted in a new database on Subduction Zone Initiation, which is now also open for community input.

Subduction zone initiation database

The SZI database provides cross-disciplinary data, unambiguous definitions, and everything else important regarding subduction zone initiation on the planet Earth.

SZI Database

By looking at multiple events, we found SZI clustering around two time periods: 6 to 16 million years ago and 40 to 55 million years ago. The study has been published in Nature Communications.

A transdisciplinary and community-driven database to unravel subduction zone initiation

Despite numerous advances in our understanding of subduction since the theory of plate tectonics was established, the mechanisms of subduction zone initiation remain highly controversial. Here, the authors present a transdisciplinary and expandable community database of subduction zone initiation ev…

Nature CommunicationsFabio Crameri

ANU researchers will be deploying ocean-bottom seismometers around Macquarie Island, a location chosen due to its potential for future Subduction Zone Initiation. Updates from the team will be available live from the Southern Ocean:

Probing the Australian-Pacific Plate Boundary: Macquarie Ridge in 3D

A team of Australian researchers are about to set off on a landmark voyage to discover more about the Earth beneath our oceans, and what triggers underwater earthquakes. Read live updates of the cruise as they go — both personal reflections and scientific background to the cruise.

Geo★ Down UnderLouis Moresi

Citation

Crameri, Fabio, Valentina Magni, Mathew Domeier, Grace E. Shephard, Kiran Chotalia, George Cooper, Caroline M. Eakin, et al. “A Transdisciplinary and Community-Driven Database to Unravel Subduction Zone Initiation.” Nature Communications 11, no. 1 (July 27, 2020): 3750. https://doi.org/10.1038/s41467-020-17522-9.