Wei-Li Hong studies how silicates in the oceans, among the most abundant minerals on our planet, absorb and neutralise carbon dioxide. A considerable amount of research has been conducted on silicate weathering on land, but according to Wei-Li, marine silicate alteration has not previously been considered important for understanding the Earth system as a whole.

“Many researchers study how processes on land affect our climate, but we have focused on research into the seafloor, and this has produced exciting results. In the past, for example, we thought that carbon dioxide was the main factor, but silicates have now proved to be just as important. My research is driven by curiosity – by a desire to uncover facts and solve problems across different scientific fields,” Wei-Li says. More than 90% of the Earth’s crust and upper mantle consists of silicon-oxygen compounds known as silicates. These have regulated the amount of carbon dioxide on our planet, and its habitability, for billions of years.

Positive news for the Earth’s future?

“Our research aims to gain a deeper understanding of the role of silicates and whether they can contribute to permanently reducing the amount of carbon dioxide in the atmosphere. If so, that would be positive news for the Earth’s future. I can also see that the information we obtain from samples collected from the seafloor is much more important than we previously thought. It creates new opportunities for making assessments about the future,” Wei-Li says.

“There are still many questions we do not have answers to. We are now working to generate data that can help us calculate the Earth’s warming. This may show us how different processes operate in different parts of the world – information that can help us draw conclusions about future climate change. I hope that our research will give us a better understanding of how the Earth heals and repairs itself,” Wei-Li says.

Field observations in Svalbard

For a few weeks each year, Wei-Li conducts research at sea aboard research vessels, often as part of collaborative projects with researchers from different countries. In 2023, one such research expedition took him to Svalbard together with Norwegian and Polish researchers. The research project has explored deep-sea sediments from the northern Pacific Ocean to the Arctic Ocean and the Barents Sea. The purpose of these expeditions is to retrieve sediment from deep beneath the seafloor using deep-sea drilling equipment. The resulting sediment cores can be several metres long and are preserved for subsequent laboratory analysis.

“There are previous research projects on the seafloor with sediment cores that are more than forty years old. We can study these and compare them with samples collected today, giving us an overview of how conditions have developed over time,” Wei-Li explains.

Simulating the ocean in the laboratory

Today, Wei-Li’s research increasingly uses simulations to complement observations, sampling and measurements.

“We will carry out the first comprehensive assessment of marine silicate alteration (MSiA) through both laboratory experiments and field observations. Recreating the conditions required for MSiA in our laboratory is challenging because we need to generate pressures of up to 340 times atmospheric pressure while working at temperatures close to freezing,” Wei-Li explains.

 

The aim of the project is to gain a better understanding of the connection between the silicon and carbon cycles in the ocean – fundamental knowledge that can help researchers predict how the Earth will respond to a warmer and wetter future.