Oxygen isotope ratio

Oxygen isotope ratios compare the amounts of two forms of oxygen atoms—called isotopes—in a substance, usually water. These isotopes are oxygen-16 and oxygen-18, which differ in weight. The ratio of oxygen-18 to oxygen-16 reveals information about the history of water, such as temperature changes or climate conditions when the water was formed or evaporated. By analyzing these ratios in ice cores or fossils, scientists can learn about past climates and environmental shifts over time. It's a key tool in understanding Earth's climate history and natural processes.