50 years ago, researchers discovered a leak in Earth’s oceans
Excerpt from the March 10, 1973 issue of Science News
A remotely operated vehicle in the western Pacific explores the Mariana Trench, the deepest oceanic trench in the world. Earth’s surface and mantle exchange water through such trenches, but the mantle may be taking on more water than it’s giving back, resulting in the ocean slowly shrinking over millions to billions of years.