The cataclysmic event that wiped out the last dinosaurs also triggered the greatest underwater landslides ever, scientists report.
A chunk of a giant comet or asteroid slammed into Mexico's Yucatan peninsula about 65 million years ago, setting off earthquakes with magnitudes estimated at 10 to 13. The seismic shock waves generated meter-high vibrations in Earth's crust all along the east coast of North America.
New research indicates that this shaking sent sediment from shallow waters sliding off the continental shelf. Once the ooze settled, it may have blanketed a region as large as 3.9 million square kilometers on the deep ocean floor—an area more than twice the size of Alaska.