By discovering a new type of seafloor vent system, a group of scientists has solved the mystery of heat loss from the Earths crust – a finding that can also help scientists interpret the evidence for past global climates more accurately.
The discovery, made by scientists at the National Oceanography Centre (NOC) and the University of Southampton in Britain, explains the long observed disconnect between the theoretical rate at which the Earth’s crust is cooling at seafloor spreading ridge flanks and actual observations.
This new class of hydrothermal venting was discovered at the Von Damm Vent Field in the Caribbean during an expedition on board the NOC-maintained Royal Research Ship James Cook.
“This will really improve our understanding of how the Earth’s interior cools,” said Bramley Murton who co-supervised this research.
The team used sonar on the autonomous-submarine to map the vent field before sending down a remotely operated vehicle (ROV) to collect samples of hydrothermal fluids and minerals.
The investigation revealed that minerals and chemistry at the Von Damm Vent site are very different to those from any other known vents.
What makes this new system different is that the source of heat driving them comes from hot rock pushed towards the seabed by low angle faults called tectonic spreading centres rather than volcanic heat from magma chambers.
“We expect this new type of vent system can be found in tectonic seafloor spreading sites across the globe,” Murton added.
However, since they are almost invisible to the traditional ways of searching for hydrothermal vents, they remained unaccounted for in scientific models of how heat and chemistry is transferred from inside the Earth’s crust.
“This research also means that ocean models of magnesium and calcium budgets will need to be updated and could lead to more accurate insights into the Earth’s past climate,” the authors concluded in a paper published in the journal Nature Communications.