Buried nearly a kilometre beneath the Atlantic seabed west of Guinea-Bissau lies a geological time-capsule: gigantic 117-million-year-old mud waves sculpted by dense, underwater avalanches. A new ...

In the mid-20th century, when people looked at a map of the world, they saw the familiar continents surrounded by vast, featureless oceans. Beneath the waves, the ocean floor was largely unknown — an ...