What Ancient Crystal Growths Reveal About The Future Of Our Oceans

If you’re ever wondering what the future of our oceans would look like as a direct result of climate change, then look no further than the walls of coastal caves located in Spain.

The mineral ‘bathtub rings’ deposited inside the Balearic island of Mallorca’s limestone Artà

Caves show a clear view of the past and an even clearer view of what may lie ahead.

That’s because these ancient cave minerals all point to one direction: during the Pliocene Epoch, a time when the Earth is as warm as what scientists are expecting by the year 2100, where high seas were far too common. And just how high do these mineral deposits say our seas were? Well, about 16 meters higher than they are today, on average.

And while these minerals show a peak in the distant past, it’s also a big clue as to what can happen in our oceans in the future, given that the ever-warming climate is causing our ice sheets to continuously melt, causing sea levels to rise.  Sure, this process is bound to happen over the course of a thousand years, yet the results remain the same: The oceans will rise, significantly reducing the land we have. In fact, it’s already happening, with coastlines of states like Louisiana slowly disappearing into the water.

Furthermore, the mineral deposits also give a clue as to how much of the Earth’s biggest ice sheet have melted during that period and how much would melt in the future, given that the Earth’s temperature will be more or less the same.

According to the researchers, they searched caves for information on the new study simply because they’re a much protected environment.  

“We don’t worry about erosion and other weathering after deposition as much as you would about terrestrial or other records,” Oana-Alexandra Dumitru, study co-author and a geochemist at the University of South Florida in Tampa who began collaborating with Mallorcan researchers as a graduate student, said.

Along with colleagues, Dumitru reportedly used a dating method that’s capable of determining when the Pliocene deposits formed. From this, they were able to determine that one of the lower deposits formed around the mid-Piacenzian Warm Period, some 3.3 or 3 million years ago. During that time, global temperatures were around 2 to 4 degrees Celsius than current times. However, they resemble the upcoming forecasts of how warm the Earth would be for the year 2100. This also means that there’s a possibility our oceans would once again rise up to 16.2 meters than they are today.

Cave Found in an Italian cave near Altamura, the "Altamura Man" was calcified almost completely into the rock. Photo courtesy of Shutterstock