Over the past 260 million years, dinosaurs have come and gone, Pangea has split into the continents and islands we see today, and humans have rapidly and irreversibly changed the world we live in.
However, even under such circumstances, the earth seems to continue to keep track of time. Research into ancient geological events suggests that our planet experiences slow, steady “beats” of geological activity approximately every 27 million years.
The pulses of clustered geological phenomena, such as volcanic activity, mass extinctions, plate realignment, and sea level rise, are incredibly slow, with catastrophic ebbs and flows occurring every 27.5 million years. But luckily, researchers think we have another 20 million years until the next “pulse.”
“Many geologists believe that geological events occur randomly over time.” said Michael Rampino, a geologist at New York University and lead author of the study.in a 2021 statement.
“However, our study provides statistical evidence for a common cycle, suggesting that these geological events are correlated and not random.”
The research team conducted an analysis of the ages of 89 well-understood geological events over the past 260 million years.
As you can see from the graph below, there have been tough times, with eight or more such world-changing events concentrated in a geologically short period of time, forming a catastrophic “pulse.”
“These events include marine and non-marine extinctions, large-scale oceanic anoxic events, continental flood basalt eruptions, sea-level changes, global pulses of intraplate magmatic activity, the rate of seafloor spreading and It includes periods of reconfiguration change.” The team wrote in their paper:
“Our results suggest that global geological events are generally correlated and appear to pulsate with an underlying period of about 27.5 million years.”
Geologists have long studied potential cycles of geological events. Back in the 1920s and ’30s, scientists at the time suggested that there was a 30-million-year cycle in the geological record, but researchers in the 1980s and ’90s suggested that the oldest They used geological events to uncover a 30-million-year cycle. The length between “pulses” ranges from 26.2 to 30.6 million years.
Everything seems to be going well right now. 27.5 million years is exactly as we expected.a Research published at the end of 2020 The same authors suggest that this 27.5 million years later is also the time of the mass extinction.
“This paper is very good, but I actually think a better paper on this phenomenon is: [a 2018 paper by] Muller and Dutkiewicz,” University of Adelaide geologist Alan Collins, who was not involved in the study, told ScienceAlert in 2021.
that 2018 Paperstwo researchers from the University of Sydney investigated Earth’s carbon cycle and plate tectonics and came to the conclusion that the cycle is approximately 26 million years long.
Collins explained that many of the events the research team investigated in this latest study are causal, meaning one directly causes the other, and therefore some of the 89 events are related. did. For example, anoxic events that cause ocean extinctions.
“That said, this 26-30 million year cycle is real and appears to exist over a much longer period of time, and it’s not clear what its underlying causes are,” he said. added.
Other research by Rampino and his team Comet impact suggested That could be the culprit, and one space researcher even suggests that Planet Nine is the culprit.
However, if the Earth really has a geological “pulse”, it may be due to something a little closer to home.
“These periodic pulses of tectonics and climate change could be the result of geophysical processes related to plate tectonics and mantle plume dynamics, or alternatively related to Earth’s motion in the solar system and galaxy. It may be regulated by astronomical cycles.” written by the team In their study.
This study Earth science frontier.
A previous version of this article was published in June 2021.