O is for Ocean Current

Ocean Current That Keeps Europe Warm Is Weakening.
As Andrea Thompson at Scientific American reports, the stronger a current is, the larger the grains of sediment it can move, allowing researchers to map changes in current strength by sediment size. The team also looked for tiny fossil critters, known as foraminifera of “forams,” to get a sense of ocean temperatures. Since some species of foram thrive in warm waters while others prefer cooler temps, researchers can use foram species as a rough thermometer for past ocean temperature.