China’s deep sea prospectors may find key to marine heatwaves

Chinese scientists scouring the seabed for minerals and other resources are also gathering environmental data which may increase understanding of marine heatwaves and their impact on global weather events.

Professor Zhai Shikui, a marine geoscientist with the Ocean University of China in Qingdao, Shandong province in eastern China, said a large number of research vessels had been deployed in the Indian Ocean as part of Chinese exploration under a UN prospecting licence.

“Our main focus has been minerals and other resources but lots of environmental data has been collected at the same time. Some of it might hold the key to answer interesting questions about underwater heating,” Zhai said.

One question the Chinese research vessels could help to answer was raised by a retired Hong Kong professor writing in the latest issue of Imperial College London’s Imperial Engineer journal.

Wyss Yim, previously a geoscientist with the University of Hong Kong, has been tracking geothermal activity beneath the world’s oceans through satellite data and has traced a dramatic rise in seawater temperature to a volcanic eruption near Madagascar in spring 2018.

The volcano, on the sea floor off the French island of Mayotte, caused numerous earthquakes but also created a mountain of magma – about 800 metres (2,600 feet) tall and 5km (three miles) wide – according to French scientists led by Marc Chaussidon, director of the Institute of Geophysics in Paris, who said it “was built from zero in six months”.

Yim’s study found the formation of the magma mountain had coincided with the temperature rise in the southwest Indian Ocean. He hypothesised that magma from the volcano had risen from the sea floor and ridden long distances on currents before spreading out when it reached the surface.