isotopes in paleoceanography

In paleoceanography, isotopes are variants of elements with different neutron counts, used to study past climates and ocean conditions. By analyzing the ratios of stable isotopes—such as oxygen isotopes (¹⁸O and ¹⁶O)—in marine fossils like foraminifera shells, scientists can infer past temperature changes and ice volume. For example, higher ¹⁸O levels typically indicate colder periods with more ice sheets, while lower levels suggest warmer times. These isotope records help reconstruct Earth's climate history, providing insights into how oceans and climate have evolved over millions of years.