In the last 260 million years, dinosaurs have come and gone, Pangaea broke up into the continents and islands we see today, and humans have rapidly changed the world we live in.
Yet through it all, Earth seems to be keeping time. Research into ancient geological events shows that our planet has a slow, steady “heartbeat” of geological activity every 27 million years or so.
The series of geological events – including volcanic activity, mass extinctions, plate reorganization and sea level rise – constituted a very slow tidal cycle lasting 27.5 million years. But luckily for us, researchers believe we have another 20 million years before the next “pulse.”
“Many geologists believe that geological events occur randomly throughout time,” said Michael Rampino, a geoscientist at New York University and lead author of the studyin a 2021 statement.
“But our research provides statistical evidence for a common cycle, showing that these geological events are interconnected and not random.”
The team analyzed the ages of 89 well-understood geological events over the past 260 million years.
As you can see from the graph below, some of these were difficult times – more than eight world-changing events occurred simultaneously in a small geological time span, forming a “pulse” of disaster.
(Rampino dkk., Frontiers of Earth Science2021)
“These events include periods of marine and non-marine extinctions, major marine anoxic events, continental flood basalt eruptions, sea level fluctuations, global pulses of magma within plates, and periods of changes in basic spreading rates oceans and plate reorganization.” the team wrote in their paper.
“Our results show that global geological events are generally interconnected, and appear to occur in a basic cycle of about 27.5 million years.”
Geologists have long studied possible cycles of geological events. Back in the 1920s and 1930s, scientists at that time stated that the geological record had a 30 million year cycle, while researchers in the 1980s and 1990s used the best dated geological events at that time to gave them a series of geological data. program. The distance between these “pulses” is 26.2 to 30.6 million years.
Now, everything seems fine, 27.5 million years is the time we estimate. A The study was published in late 2020 The same authors argue that this 27.5 million year period is when the mass extinction also occurred.
“This paper is very good, but I think this is a better paper on this phenomenon [a 2018 paper by] Müller and Dutkiewicz,” tectonic geologist Alan Collins of the University of Adelaide, who was not involved in the research, told ScienceAlert in 2021.
Which 2018 paperTwo researchers at the University of Sydney studied the Earth’s carbon cycle and plate tectonics, and also came to the conclusion that the cycle lasts about 26 million years.
Collins explained that in this latest research, many of the events studied by the team were causal events, meaning one event directly caused another, so some of the 89 events were related to each other: for example, the hypoxic event that caused marine extinction.
He added: “Nevertheless, this 26-30 million year periodicity appears to be real and lasts over a much longer period of time – and it is also unclear what the reasons behind it are!”
There is other research conducted by Rampino and his team Proposed comet strike This could be the reason, and one space researcher even suggested that Planet Nine was the reason.
But if Earth does have a geological “heartbeat,” it may be caused by something closer to Earth.
“These periodic tectonic waves and climate changes may be the result of geophysical processes related to the dynamics of plate tectonics and mantle plumes, or they may also be rhythmized by astronomical cycles related to the movement of the earth in the solar system and galaxy.” Tim wrote In their studies.
This research was published in Frontiers of Earth Science.
An earlier version of this article was published in June 2021.
2023-11-10 06:33:45
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