Scientists have found that major geological events, such as mass extinctions and volcanic eruptions, repeat themselves every 27 million years. “A pulse of the Earth” is what scientists are calling it in a new study. According to geologist Michael Rampino, who is the lead author of the study, believes that there is no pattern in geological events over time. “But our study provides statistical evidence for a common cycle, suggesting that these geologic events are correlated and not random," said Rampino in a news release by the New York University, where he works as a professor. The study was published in Geoscience Frontiers on June 17.
Scientists gathered data for the last 260 million years and analysed 89 major geological events for patterns. These events include mass extinctions of species living on land and ocean, huge volcanic eruptions, depletion of oxygen from the seas, big fluctuations in the sea level and major movement and reorganisation of the Earth’s tectonic plates. When the researchers plotted the data and conducted a statistical analysis, they found that these events formed clusters at 10 different points in time. They further showed that the events peaked about every 27.5 million years. The analysis also revealed that the last peak happened about seven million years ago and there are 20 more million years to go before major geological changes on the planet.
Finding patterns in major geological events has been a hot interest for geologists for over five decades. However, according to the researchers, they were not able to do it because the data of such events was not accurate, thanks to not-so-advanced dating techniques. Now that there have been significant improvements in radio-isotope dating techniques, major changes have been recorded in the geologic time scale. Thanks to that, Rampino and his team were able to compile an updated record that could capture the geologic “pulse of the Earth.”
The reason behind this loop, however, is not very clear to the geologists. The researchers suggest that these pulses may be connected to the cycles of activity happening inside the Earth that affect tectonic plates’ movement and climate.