From the atmosphere to the abyss: Iron’s role in Earth’s climate history
57 seconds ago Anthony Watts No Comments
A new study published by researchers at the University of Hawai‘i (UH) at Mānoa sheds light on the critical role of iron in Earth’s climate history, revealing how its sources in the South Pacific Ocean have shifted over the past 93 million years. This groundbreaking research, based on the analysis of deep-sea sediment cores, provides crucial insights into the interplay between iron, marine life, and atmospheric carbon dioxide levels.
Iron is a vital nutrient for marine life and plays a significant role in regulating atmospheric carbon dioxide by influencing the growth of phytoplankton, which absorb carbon dioxide. Although the importance of iron today is well-established, researchers have a limited understanding of how past iron availability may have shaped the marine ecosystem.
To investigate the long-term history of oceanic iron, the researchers meticulously analyzed iron isotopes in three deep-sea sediment cores from the South Pacific, far removed from continental influences.
Red-brown clays recovered from deep sea sediment cores in the Pacific Ocean. Credit Richard W. Murray
“Over the past 93 million years, we found that five primary sources of iron have influenced the South Pacific Ocean: dust, iron from far off ocean sources, two distinct hydrothermal sources, and a volcanic ash,” explained Logan Tegler, the lead author and oceanography postdoctoral researcher in the UH Mānoa School of Ocean and Earth Science and Technology. “These sources shifted over time as the sites gradually migrated away from mid-ocean ridges.”
https://wattsupwiththat.com/2025/08/26/from-the-atmosphere-to-the-abyss-irons-role-in-earths-climate-history/
