A young subduction zone off the coast of New Zealand has helped scientists explain the mystery of how a tectonic plate can break through the Earth’s hard crust and initiate the process of diving beneath another plate.
The recently published study in Nature Geoscience describes how a small fault in a tectonic plate has been continuously compressed and pulled for millions of years, until the pressure built up strong enough to trigger a major geological process.
The project began in 2018 with an expedition aboard the research vessel Marcus G. Langseth off the coast of New Zealand. Here, Dr. Brandon Shuck from Columbia University’s Lamont-Doherty Earth Observatory collected detailed seismic images of the ocean floor.
The Earth has a young subduction zone off the coast of New Zealand – (Photo: Brandon Shuck)
The images were combined with samples from other oceanic expeditions, providing geological timelines to reconstruct a tumultuous period in history.
According to PHYS, evidence shows that 16 million years ago, a small crack began to form in the Australian tectonic plate. This crack gradually widened as it collided with other tectonic plates—because, as we know, tectonic plates, simply put, are pieces of the Earth’s crust that are always in motion.
When the crack became long and large enough, the heavier part of the Australian plate was able to penetrate the Earth’s rocky crust and gradually dive beneath it over the past 800 million years. This is a relatively small subduction zone on a global tectonic scale, but evidence suggests that the crack will continue to grow, extending to Antarctica and gradually altering the landscape over the next hundreds of millions of years.
As many other studies have shown, the Earth’s crust is not continuous like that of most other planets, but is made up of 15-20 large and small pieces. These pieces continuously slide past each other, diving underneath one another through the subduction process… carrying along with them the continents and oceans that are constantly changing.
This entire process is collectively known as “plate tectonics,” which may sound daunting but is crucial for helping the Earth maintain a stable environment, atmosphere, and sustain life.
This process has repeatedly caused the land on the planet to merge into a supercontinent, surrounded by a superocean, and then repeatedly pull apart, separating into many continents as we see today.
