A team led by researchers from the Woods Hole Oceanographic Institution has published a study into how our oceans first got their oxygen.
The combination of water and oxygen was instrumental to life on the planet, but up to now, very little was known about how the ocean acquired oxygen in the first place.
Describing the study and the driving question behind it, Andy Heard, lead author of the study and assistant scientist at WHOI said:
“At that point in Earth’s history, nearly all life was in the oceans. For complex life to develop, organisms first had to learn not only to use oxygen, but simply to tolerate it…Understanding when oxygen first accumulated in Earth’s atmosphere and oceans is essential to tracing the evolution of life. And because ocean oxygenation appears to have followed atmospheric oxygen surprisingly quickly, it suggests that if we detect oxygen in the atmosphere of a distant exoplanet, there’s a strong chance its oceans also contain oxygen.”
Describing the role of South Africa in the research, Chad Ostrander, one of the study’s co-authors and an isotope geochemist at the University of Utah, added:
“South Africa is one of the few places on Earth with exceptionally well-preserved rock records from this pivotal time in our planet’s history. These sedimentary rocks play host to some of our strongest indicators for the rise of atmospheric oxygen. These rocks have relatively tight age constraints, and within them we see the disappearance of sulfur mass-independent fractionation — the traditional ‘smoking gun’ evidence for a GOE.”
Sune Nielsen, one of the study’s co-authors and adjunct scientist at WHOI, described the role Vanadium plays, stating:
“Vanadium is especially powerful because it responds to relatively high levels of dissolved oxygen compared to other geochemical proxies used for this period of Earth’s history. That means we can detect when oxygen in the oceans first rose above roughly 10 micromoles per liter — a few percent of modern levels.”
