Geoscience: Earth’s mantle motion has kept Nile stable for 30 million years
Nature Geoscience
2019년11월12일

The drainage pathway of the River Nile has persisted over the past 30 million years, because a conveyor-belt-like motion, or ‘convection cell’, in the Earth’s mantle has stabilized surface topography according to a paper published in Nature Geoscience.
Drainage systems of large rivers have long been a puzzle, and two competing possibilities were suggested for the evolution of the River Nile. In one scenario, river flow from Ethiopia to the Mediterranean has been active for the past 30 million years. Alternatively, drainage pathways at that early time led from Ethiopia westward towards the Congo Basin or northwestward towards the Sirte basin, and a connection to the Mediterranean was established much later, about 5 to 8 million years ago.
Claudio Faccenna and colleagues present geological and geophysical evidence as well as simulations with a geodynamical model that suggest an early establishment of present-day drainage pathways. They find that since about 30 million years ago, a convection cell has operated in the Earth’s mantle, with upwelling and topographic rise beneath Ethiopia and downwelling associated with sinking under the eastern Mediterranean Sea, which led to the current drainage pattern.
doi: 10.1038/s41561-019-0472-x
리서치 하이라이트
-
3월4일
Environment: Reservoirs account for more than half of water storage variabilityNature
-
3월2일
Evolution: Neanderthals may have heard just like usNature Ecology & Evolution
-
3월2일
Geoscience: Earth’s atmosphere may return to low-levels of oxygen in one billion yearsNature Geoscience
-
2월26일
Environment: Shifting from small to medium plastic bottles could reduce PET wasteScientific Reports
-
2월24일
Environment: European forests more vulnerable to multiple threats as climate warmsNature Communications
-
2월11일
Environment: Global CFC-11 emissions in declineNature