WASHINGTON: American and Italian researchers have examined limestone that explains the mass extinction of marine life around 183 million years ago.
Research findings published in the journal PNAS warn of the dangerous effects of oxygen depletion and climate change on existing oceans.
Many marine reptiles flourished during the Jurassic period, but volcanic activity in present-day South Africa released an estimated 20,500 gigatons of carbon dioxide over 500,000 years, reducing oxygen levels in the oceans and resulting in the extinction of many marine species. The creatures became extinct.
By studying the sediments of limestone that absorb chemicals released by volcanic eruptions, the researchers inferred changes in oxygen levels in the oceans during ancient times. Researchers found that up to 8 percent of the ancient world’s oceans were completely depleted of oxygen and covered an area roughly three times the size of the United States.
