For the last five decades, researchers have suspected that our planet’s major geological events occur in a cycle – but couldn’t get the data to properly back it up. However, with technology coming on in leaps and bounds, geologists have since been able to show that Earth does in fact have a beating geological heart, although the reason why remains elusive.
Researchers from the New York University and the Carnegie Institution for Science analyzed the ages of 89 major geological events that occurred during the last 260 million years – including mass marine and land extinctions, sea level fluctuations, and tectonic plate changes – in the hopes of uncovering a cyclical pattern.
Luckily for them, they found one – using a mathematical technique called Fourier analysis, they discovered that the events were clustered at 10 different time points over the 260-million-year time frame. This means that roughly every 27.5 million years, there is a “pulse” of major geological activity.
“Many geologists believe that geological events are random over time. But our study provides statistical evidence for a common cycle, suggesting that these geologic events are correlated and not random,” said Michael Rampino, the study’s lead author, in a statement.
The next step is to establish why this cycle exists. In their paper, the authors point to research suggesting that linked cycles of global tectonics and climate change could be at play. In a study published this month, two of the researchers explore this possibility in further detail, as well as a potential link with astronomical cycles on both Solar System and wider astronomical levels.
“Whatever the origins of these cyclical episodes, our findings support the case for a largely periodic, coordinated, and intermittently catastrophic geologic record, which is a departure from the views held by many geologists,” explained Rampino.
If you’re feeling concerned about when the next batch of events might hit, you needn’t worry. The last cluster occurred around 7 million years ago, meaning there are a good 20 million years to go before the Earth’s next big temper tantrum – plenty of time to prepare.
The study is published in Geoscience Frontiers.