An Israeli-Dutch research team says it has discovered the secret of why the world looks as it does — from the location and shape of continents to the lay of the land in mountain ranges.
Tectonic plates didn’t move randomly, but rather in a previously unknown chain reaction in which one event in the Earth’s crust triggered another, sometimes many millions of years later.
After spending years studying the ocean floor, the team has just published peer-reviewed research in the journal Nature Geoscience. It says that volcanic eruptions 105 million years ago under Madagascar set off a domino effect of other such events that determined how the Earth looks today.
The research is focused on how tectonic plates — pieces of Earth’s crust and uppermost mantle — have behaved over time. “Until today we had quite a poor understanding of the history of plate motions and the tectonic events that happened long ago, but this has changed,” Prof. Roi Granot told The Times of Israel.
“For the first time, we now have an organizing principle that explains how one tectonic event led to another, and so on,” he said. “We never before had such documentation, and our observation shows there’s a causality between the events, with one triggering the next.”
Granot, a Ben Gurion University geoscientist, added: “This gives us a framework to understand when and why the world saw the creation of mountain belts, volcanic activity, ocean formation, climate and much more.”
Granot and colleagues have documented what they believe to be the main events shaping Europe, Asia and Africa, and say they are confident that similar chain reactions will be observed in other areas.
The research is allowing them to gradually piece together the past — but they say it’s not yet giving any glimpse into what future movements the Earth’s crust may have in store.
Granot worked with Dutch academics Prof. Douwe van Hinsbergen and Derya Gürer to track tectonic activity by gathering information from the floor of the Central and Northern Atlantic. Much of it came from hundreds of magnetometers — devices for measuring the strength of magnetic fields — that have trailed under ships over recent years, some of them several kilometers below the surface.
By analyzing the magnetic field of rocks, the magnetometers provided data that Granot and colleagues used to piece together the history of plate tectonics, as archaeologists use carbon dating to construct their hypothesis about the past.
Magnetometer data wasn’t thought capable of giving a clear picture of plate history until a breakthrough by Granot 10 years ago illustrated that data can be used to date the oceanic crust.
Gürer, a researcher at Utrecht University and the Australian National University, commented: “This is the first time that evidence has been found for a plate tectonic chain reaction.
“With this research, we have dissected a mechanism to explain why there are short periods of time in which plates suddenly change direction,” she said.
“These plate movements affect mountain formation, marine gateways, ocean circulation patterns, volcanism, and even the global climate.”