Eruptions of volcanoes under the ocean were believed to be slow and steady occurrences that their impact on the Earth's climate cycle has often been ignored under the presumption that they have small influence.
Findings of a new study, however, suggest that these ocean floor eruptions could influence the climate cycle of the Earth and that predictive models, including the ones that analyze the impact of humans on climate change, may need to be changed.
Scientists previously presumed that seafloor volcanoes ooze lava at a slow and steady pace but geophysicist Maya Tolstoy, from the Columbia University's Lamont-Doherty Earth Observatory and the author of the new study published in the Geophysical Research Letters, believe that these volcanoes erupt in burst and that they have remarkably consistent patterns ranging from as short as two weeks to as long as 100,000 years.
Tolstoy's study aims to determine how often underwater volcanoes erupt and what drives these eruptions. She found that the volcanism of our planet is associated with shifts in how the Earth moves around the sun every 100,000 years and these shifts cause ice ages and warm periods that affect the rise in global sea level.
She has likewise noted that the underwater eruptions were not included as factor in models of Earth's climate system used to project the ocean and atmospheric conditions in the future.
"Seafloor spreading is considered a small but steady contributor of CO2to climate cycles on the 100 kyr time scale, however this assumes a consistent short-term eruption rate. Pulsing of seafloor volcanic activity may feed back into climate cycles, possibly contributing to glacial/inter-glacial cycles, the abrupt end of ice ages, and dominance of the 100 kyr cycle," Tolstoy wrote.
The researcher in particular found that spurts in volcanic activities correspond with periods of low ocean tides. Tolstoy also found that the eruptions happen during the first six months of the year when the Earth draws away from the sun.
The implication of the study is that as the sea levels rise because of climate changes, they could mimic suppressed underwater volcanic activity which could eventually affect the climate in the future.
Another study published in the journal Science on Jan. 28 also shows an association between underwater eruptions and fluctuations in the atmosphere.
"People usually study what happens on the surface of the Earth and the interior of Earth totally separately, so people doing climate modeling won't include what's happening under the ground and then people under ground ignore what's on the surface," said study author John Crowley, from Department of Earth Sciences at the University of Oxford. "But there's actually a strong link between the two."
