Earth has been around for about 4.5 billion years, and in that time, the planet has undergone some dramatic changes. These include the formation and breakup of supercontinents, the appearance and disappearance of oceans, extreme ice ages that nearly blanketed the globe with ice, and multiple mass extinctions that wiped out as much as 96 percent of all life at the time.
Compared with its volatile younger self, the Earth of today seems pretty tame. But our world is also a dynamic planet, and there is much about its history and ongoing processes — on land, in the oceans and deep under the surface — that scientists are still discovering. Here are just a few examples of times during the past year when new findings about oddball Earth threw us for a loop.
On March 19, a gaping chasm yawned in Kenya’s Great Rift Valley, following heavy rains and seismic activity. The rift measured several miles long and was over 50 feet (15 meters) wide, and it represents shifts that are currently taking place deep below Earth’s surface, in crustal plates under Africa.
Africa sits atop two plates: Most of the continent rests on the Nubian plate, but part of eastern Africa lies on the Somali plate. Tectonic shifts, driven by the active mantle, are pulling the plates apart, which can open rifts in the surface. However, it will take tens of millions of years for the continent to separate into two pieces.