Geologists have been investigating a potential cycle in geological events for a long time. A recent analysis on the ages of 89 well-understood geological events from the past 260 million years show a catastrophic 27.5 million year pulse in eight clusters of world-changing geologic events over geologically small timespans. This pulse of clustered geological events – including volcanic activity, mass extinctions, plate reorganizations, and sea level rises – is incredibly slow, a 27.5-million-year cycle of catastrophic ebbs and flows.
As you can see from the graph, some of those times were tough – with over eight of such world-changing events clustering together over geologically small timespans, forming the catastrophic ‘pulse’. “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,” the team writes in their paper. These cyclic pulses of tectonics and climate change may be the result of geophysical processes related to the dynamics of plate tectonics and mantle plumes, or might alternatively be paced by astronomical cycles associated with the Earth’s motions in the Solar System and the Galaxy. Luckily for us, the research suggests we have another 20 million years before the next ‘pulse’.