How Earth’s Shifting Plates Trigger Changes In The Planet Every 36 Million Years
by Trisha Leigh
Everything old is new again – which, it turns out, is true even for the entire planet that we call home.
In this case it might take 36 million years, but when it happens, marine ecosystems all over the globe are rejuvenated by massive surges in biodiversity.
The cycle is triggered, scientists say, by geological changes and plate tectonics. When the plates shift they force changes in sea levels – a cycle that takes place roughly every 36 million years, according to new research.
Professor Dietmar Muller of the University of Sydney expanded in a statement.
“In terms of tectonics, the 36-million-year-cycle marks alterations between faster and slower seafloor spreading, leading to cyclical depth changes in ocean basins and in the tectonic transfer of water into the deep Earth. These in turn have led to fluctuations in the flooding and drying up of continents, with periods of extensive shallow seas fostering biodiversity.”
They discovered this by studying peaks and troughs in marine biodiversity. They linked them to changes in sea level brought on by the movement of tectonic plates, and in the end, they weren’t shocked to uncover a regular cycle.
“This research challenges previous ideas about why species have changed over long periods. The cycles are 36 million years long because of regular patterns in how tectonic plates are recycled into the convecting mantle, the mobile part of the deep Earth, similar to hot, thick soup in a pot, that moves slowly.”
It is wild to think about how long of a cycle that actually is, compared to our puny little lives.
I can’t decide whether it’s comforting or the opposite of comforting to think about how the planet existed long before us, and will continue on long after us.
I guess in the (super) long run it doesn’t really matter.