New research helps explain what drives the mysterious process in which ocean water circulates through the seafloor and volcanic rock of the upper crust.
About 25 percent of the heat that is released from the Earth's interior is transported through this process, the University of California, Santa Cruz reported. The process was tracked through thousands of extinct underwater volcanoes and porous volcanic rock exposed on the seafloor.
"Ever since we discovered a place where these processes occur, we have been trying to understand what drives the fluid flow, what it looks like, and what determines the flow direction," said Andrew Fisher, professor of Earth and planetary sciences at UC Santa Cruz.
In this new study, the researchers developed the first three-dimensional computer models of the heat and water transfer process. The models showed a "hydrothermal siphon" was driven by hear loss from within the Earth as well as the flow of cold seawater into the crust.
The model shows the water tends to enter the crust through the underwater where fluid flow easiest because of certain rock properties and sizes. On the other hand, the water is most likely to discharge in spots where fluid flow is more difficult because of the opposite rock properties and sixes. The findings suggests smaller seamounts are most likely to be regions of hydrothermal discharge.
"This modeling result was surprising initially, and we had to run many simulations to convince ourselves that it made sense," said first author Dustin Winslow, a UCSC Ph.D. candidate who graduated this month. "We also found that models set up to flow in the opposite direction would spontaneously flip so that discharge occurred through less transmissive seamounts. This seems to be fundamental to explaining how these systems are sustained."
The findings were published in a recent edition of the journal Nature.
