The natural forces that shaped our planet, such as the formation of oceans, seas and ice ages are gradual processes that take thousands if not millions of years. Right? Wrong!
According to several studies, geological and climatological change on our planet might be, in some cases, a much faster process than we could have ever imagined.
The biggest flood ever
About six million years ago the Mediterranean was a much different place than it is today. In fact, it was a desert.
Having been cut off from the Atlantic Ocean at the strait of Gibraltar by a tectonic upheaval, the sea started to dry up and soon became an arid and salty basin, nearly 500 m deep.
It wasn’t until a second round of tectonic activity opened up a small crack in the piece of land separating the Mediterranean and Atlantic that water started to flow back into the former sea. According to Daniel Garcia-Castellanus of Spain’s Consejo Superior de Investigaciones Cientificas (CSIC), what started as a trickle increased exponentially, as more rock was eroded, and more water was let through, which in turn eroded more rock.
Garcia-Castellanus estimates that, at its maximum, water would have flowed at 1,000 times the rate of the Amazon, moving at hundreds of kilometers per hour and filled the basin at a rate of 10 metres per day, making it the greatest flood on record.
The inflowing water cut a trough in the seafloor 200 km long, 6-11 km wide, and more than a half kilometer deep in places. It was the discovery of this trough — now filled with sediment — that has given researchers their first clues about this violent event, which they estimate took place in a very short period of time, as brief as a few months.
Ice ages pulling a ‘pop-in’
Nary a day goes by without someone, somewhere, talking about global climate change. And while the general consensus among credible scientists is that we are warming our planet at an unprecedented and alarming rate, researchers at the University of Saskatchewan believe that they have found evidence that an ice age took only a few short months to take hold.
Known colloquially as “the big freeze,” the Younger Dryas, which occurred approximately 12,800 years ago, could be described as a mini ice age.
The Younger Dryas was brought upon by a break in a glacial dam, separating lake Agassiz from the North Atlantic and Arctic oceans. The result of this was a flood of fresh water amounting to more than the entire volumes of all the Great Lakes combined, which mixed with the salty ocean water, and halted the currents that normally bring warm water from the equator northward.
Soon after, temperatures in the northern hemisphere dropped, ice sheets started to expand, and large populations of early human civilizations crumbled, possibly due to crop failures.
It had been thought that this temperature shift originally took place over a period of several years, however new evidence, gathered by studying core samples from an Irish lake in excruciating detail, suggests that the temperature change may have occurred in a matter of months.
This discovery is especially topical now, as some climate researchers believe that a massive sheet of ice on Greenland’s coast might be poised to fall into the ocean — creating a situation similar to the breaking of Agassiz’s glacial dam — with the potential to plunge the northern hemisphere into a modern “big freeze.”
What will we call the new sea?
In September 2005, a volcano, called Dabbahu, located in northeastern Ethiopia, erupted underground, creating a massive 60-km long and 8-km wide wedge of magma, which is currently trying to cleave Ethiopia in two.
The magma wedge, or dike as they are called, formed between the Arabian and African tectonic plates, and proceeded to push the two plates apart with so much force that it opened a 500 m long, 60 m deep crack in the surface of the Earth’s crust in a matter of a few days.
Researchers have postulated that if the dike continues to force the continental plates apart, the crack could expand, eventually reaching Ethiopia’s east coast, where it would fill with water, creating a new sea. Although Cynthia Ebinger, a researcher studying the crack’s formation, doesn’t think this will happen too soon, so don’t lie awake at night worrying about it.
Interestingly, the crack formed in a manner similar to how mid oceanic ridges form — which are typically difficult to study, as they normally occur at great depth — and is giving scientists a unique opportunity to study this geological phenomenon.
So there you have it, three examples of our planet changing at a violently rapid rate, helping to dispel the myth that the processes, which shaped our earth, took eons occur. Perhaps we will have to stop using the term “geologically slow,” or at least adapt it to our modern understanding. Although “geologically quick” doesn’t have quite the same ring to it.