Reviewing ancient geology predicts that the earth's heartbeat would pulsate in 20 million years, at a slow and steady rhythm of 27 million years.
Earth's Heartbeat: Slow and Steady
Over the past 260 million years, Earth has witnessed the rise and fall of dinosaurs, the breakup of Pangea into today's continents and islands, and the rapid, irreversible alterations caused by human activity. Amidst this dynamic history, Earth seems to maintain a rhythmic pulse. Extensive research into ancient geological events reveals a slow, consistent "heartbeat" occurring approximately every 27 million years.
This pulse encompasses clustered geological phenomena-volcanic activity, mass extinctions, plate reorganizations, and sea level rises-manifesting as a 27.5-million-year cycle of catastrophic ebbs and flows. Fortunately, scientists estimate there will be around 20 million years before the next anticipated 'pulse.' While conventional wisdom held that geological events were random, a 2021 study led by Michael Rampino, a New York University geologist, presents statistical evidence supporting a common cycle.
Analyzing 89 well-understood geological events from the last 260 million years, the study identifies over eight world-changing events clustering within relatively small geologic timespans, forming the catastrophic 'pulse.'
27.5-Million-Year Cycle
The research team identifies a spectrum of significant events, including marine and non-marine extinctions, ocean-anoxic events, continental flood-basalt eruptions, sea-level fluctuations, global intraplate magmatism, and alterations in seafloor-spreading rates and plate arrangements. Their findings indicate a broad correlation among global geological events, occurring in pulses with an inherent ~27.5-million-year cycle.
Geologists have long explored the possibility of such a cycle, with earlier notions in the 1920s and 30s proposing a 30-million-year pattern. In the 1980s and 90s, research narrowed the range to 26.2 to 30.6 million years based on the best-dated geological events of the time. Now, the evidence aligns, suggesting the expected 27.5-million-year cycle. A 2020 study by the same authors even links this interval to mass extinctions.
Tectonic geologist Alan Collins from the University of Adelaide, not involved in this research, acknowledges its quality but points to a 2018 paper by Muller and Dutkiewicz, also proposing a 26-million-year cycle, as particularly noteworthy in exploring Earth's carbon cycle and plate tectonics.
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Cause of the Earth's Heartbeat
In this study, Collins notes that many of the examined events have causal relationships, where one directly triggers another, such as anoxic events leading to marine extinction. The observed 26-30 million year cyclicity appears genuine, but its underlying cause remains unclear over the extended timeframe. Previous research by Rampino's team proposed comet strikes or even the hypothetical Planet Nine as potential causes.
owever, the notion of Earth's geological 'heartbeat' might be more grounded. The research team suggests that these cyclic pulses, influencing tectonics and climate change, could stem from geophysical processes linked to plate tectonics and mantle plumes. Alternatively, they may be influenced by astronomical cycles tied to Earth's motions in the Solar System and the Galaxy.
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