Mehar reported in mid-2021 that according to many geologists [Who?], geological activity on Earth is a rare event. Plate tectonic theory implies that episodes of various regional geological events should manifest global patterns of plate dynamics and mantle-plume activity. But, a new study offers statistical evidence for a common cycle- suggesting that these geological events are correlated. Scientists from New York University and the Carnegie Institution of Science in Washington D.C. analyzed 260 million years of geological feedback. They found that our Earth has a heartbeat- that goes off on a regular schedule, albeit with millions of years in between.
The study suggests that Earth has a pulse- a 27.5-million-year cycle of geological activity. That means a geologic activity on Earth follows a 27.5-million-year cycle, giving the planet a ‘pulse.’ Significant improvements have been made on radio-isotopic dating techniques and changes in the geologic timescale, leading to new data on the timing of past events in Earth’s geological history. Scientists used the latest age-dating data available: They compiled updated records of major geological events over the last 260 million years and conducted new analyses.
A spectral analysis was performed on the ages of 89 well-dated major geological events of the last 260 Myr. These events include times of marine and non-marine extinctions, major ocean-anoxic events, continental flood-basalt eruptions, sea-level fluctuations, global pulses of intraplate magmatism, and times of changes in seafloor-spreading rates and plate reorganizations.
They found that these global geologic events are generally clustered at ten different time points over the 260 million years, grouped in peaks or pulses of roughly 27.5 million years apart. The most recent cluster of geological events was approximately 7 million years ago. It means the next pulse of significant geological activity is more than 20 million years in the future.
According to scientists, these cyclic pulses may be the result of geophysical processes related to the dynamics of plate tectonics and mantle plumes. However, similar cycles in the Earth’s orbit in space might also be pacing these events. Michael Rampino, a geologist and professor in New York University’s Department of Biology, as well as the study’s lead author, said, “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.”
Rampino, et al., conducted moving-window and spectral analyses on the record of 89 major geologic events of the last 260 Myr, including marine and non-marine extinctions, ocean-anoxic events, sea-level oscillations, continental flood-basalt eruptions, pulses of intra-plate magmatism, and changes in seafloor spreading rates. Moving window-analysis shows ten peaks (or clusters) in the number of dated events (peaks having 5 to 11 events) over the last 260 Myr centered at ~ 10, 34, 63, 95, 122, 141, 184, 201, 217, and 255 Ma, with an average interval between peaks of 27.5 Myr. Fourier analyses of the ages of the events produced spectra with significant peaks at 27.5 Myr and 8.9 Myr. Similar cycles of 26–36 Myr and 8–10 Myr have been reported in these and other aspects of geologic and climatic changes. The question of the precise lengths of the cycles, however, which may depend upon the statistical techniques utilized and differences in the various datasets, is still open.
The correlations and cyclicity seen in the geologic episodes may be entirely a function of global internal Earth dynamics affecting global tectonics and climate, but similar cycles in the Earth’s orbit in the Solar System and in the Galaxy might be pacing these events. Whatever the origins of these cyclical episodes, their occurrences support the case for a largely periodic, coordinated, and intermittently catastrophic geologic record, which is quite different from the views held by most geologists [views of Uniformitarianism and opposed to Cataclysms)?]
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