Undersea volcanos influence climate change

Feb 06, 2015, 4:19 PM EST
Close up deep sea fish hiding in rocks
Steven Bach/Steven Bach

Scientists have said for years how on-land volcanos influence swings in climate patterns, but now they are looking at how undersea volcanos also contribute to changes in the global climate. A new study suggests that underwater eruptions influence the planet's climate cycle. TIME reports:

“People have ignored seafloor volcanoes on the idea that their influence is small—but that’s because they are assumed to be in a steady state, which they’re not,” said Maya Tolstoy, a geophysicist and author of the study that appeared in Geophysical Research Letters and was also reported on in Science Daily.
Until now, scientists presumed that seafloor volcanoes exuded lava at a slow and steady pace, but Tolstoy thinks that not only do the volcanoes erupt in bursts, they follow remarkably consistent patterns that range anywhere from two weeks to 100,000 years.
Until now observing undersea eruptions has been nearly impossible, but Tolstoy and her colleagues used sensitive new seismic instruments that allowed them to monitor 10 submarine eruption sites. They also created new high-resolution maps showing outlines of pass lava flows, spanning more than 700,000 years back.
The long-term eruption data revealed that when the Earth cooled, and sea levels dropped, pressure on volcanoes let up and eruptions surged. However, when things warmed up and sea levels rose (to levels similar to what they are today), lava erupted more slowly, creating bands of lower topography. This could be due to the weight of the ocean impacting eruptions.
According to the study, this could also be related to changes in the earth's orbit. When the orbit is more elliptical, Earth is squeezed and unsqueezed by the Sun's gravitational pull, essentially massaging undersea magma upward, researchers explain. When the orbit is circular, though, the squeezing effect is minimized and there are fewer eruptions.