Optics in Oceanography: Snapshots from the Field

Some say that humans know more about outer space than “inner space”: the oceans that make up roughly 70 percent of Earth’s surface. At optical wavelengths, the deep sea is more inscrutable than the sky: light attenuates through water at short distances that fail to register on the astronomical scale. Still, the oceans critically influence the planet’s climate, human nutrition and well-being, and more. And—while acoustic techniques such as echo sounding and sonar still have a place in underwater exploration—oceanographers are increasingly employing optical imaging and sensing to gain new insights into this vast, hidden realm. This article looks at just a few examples.