Underwater Eruptions and Climate Change

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Read any drug store romance novel and you’ll learn that fire and ice don’t mix. But when it comes to climate change, that may not be the case.

For millions of years, sea level has risen and fallen at the hand of climate change, and the ebb and flow matches with valleys and ridges on the seafloor.

This suggests that ice ages have an influence on underwater volcanic eruptions. The author of one study believes that the 37,000 miles of volcanic chains beneath the surface could produce enough carbon dioxide to affect global temperatures.

“Surprisingly, the deep seafloor matters in the long-term climate cycle,” said Maya Tolstoy, lead author of the study and a marine geophysicist at the Lamont-Doherty Earth Observatory in New York.

These underwater chains, known as spreading ridges, are where oceanic crust is born as molten rock fills the spaces between moving tectonic plates. The molten rock cools, cracks and sinks to make gaps between volcanic lines, forming the ridges and valleys that we see on the seafloor.

Tolstoy’s study at the East Pacific Rise spreading ridge tries to connect ice age cycles and seafloor corrugations that extend back 800,000 years.

“The bands of thicker and thinner crust correspond to 100,000-year ice age cycles. When glaciers expanded and sea level dropped, more lava oozed from the ridge volcanoes, Tolstoy discovered. The thinnest crust, which formed when eruptions slowed, matches up with eras of higher sea level.”

A separate study focused on the seafloor around Australia and the Antarctic found similar results, but both suggest there could be a complex feedback loop involving ice ages, sea level changes and bursts of volcanic activity.