A Rift in the Rift

Curious geological happenings in Africa. From Der Spiegel:

Violent Seismic Activity Tearing Africa in Two
Cynthia Ebinger, a geologist from the University of Rochester in New York, could hardly believe what the caller from the deserts of Ethiopia was saying. It was an employee at a mineralogy company -- and he reported that the famous Erta Ale volcano in northeastern Ethiopia was erupting. Ebinger, who has studied the volcano for years, was taken aback. The volcano's crater had always been filled with a bubbling soup of silver-black lava, but it had been decades since its last eruption.

The call came last November. And Ebinger immediately flew to Ethiopia with some fellow researchers. "The volcano was bubbling over; flaming-red lava was shooting up into the sky," Ebinger told SPIEGEL ONLINE.

The earth is in upheaval in northeastern Africa, and the region is changing quickly. The desert floor is quaking and splitting open, volcanoes are boiling over, and seawaters are encroaching upon the land. Africa, researchers are certain, is splitting apart at a rate rarely seen in geology.

The first fracture appeared millions of years ago, resulting in the Red Sea and the Gulf of Aden. The second fracture, stretching south from Ethiopia to Mozambique, is known as the Great Rift Valley, and it is lined with several volcanoes. Millions of years from now, it too will be filled with seawater.

But not this part of the continent:

But in the Danakil Depression, in the northern part of the valley, the ocean could arrive much sooner. There, low, 25 meter (82 foot) hills are the only thing holding back the waters of the Red Sea. The land behind them has already dropped dozens of meters from previous levels and white salt deposits on the desert floor testify to past encroachments of the sea. But lava soon choked off its access.

For now, no one can really say when the sea will finally flood the desert. But when it does, it could go quickly. "The hills could sink in a matter of days," Tim Wright, a fellow at the University of Leeds' School of Earth and Environment, said at a recent conference hosted by the American Geophysical Union (AGU) in San Francisco.

In the last five years, the geologic transformation of northeastern Africa has "accelerated dramatically," says Wright. Indeed, the process is going much faster than many had anticipated. In recent years, geologists had measured just a few millimeters of movement each year. "But now the earth is opening up by the meter," says Loraine Field, a scholar at the University of Bristol who also attended the conference.

There is a photo gallery with the article -- here are three: