“We’re amazed at how rapidly things emerge and then disappear in the blink of an eye,” said Vincent Santucci, senior paleontologist at the National Park Service who has documented and collected fossils from eroding cliffs and shorelines. “When we have low water levels, there are sometimes fossils that are exposed that we have not seen in our lifetime and may have never been documented. We rush to preserve those.”
Some came from a creature called acrocanthosaurus, a three-toed, bipedal carnivore that looked like a slightly smaller Tyrannosaurus rex, according to Stephanie Garcia, a spokesperson for the park. As an adult, it would have stood about 15 feet tall and weighed about seven tons. Another set of footprints came from a four-legged, long-necked herbivore called sauroposeidon that stood a towering 60 feet tall and weighed about 44 tons.
With rain in upcoming forecasts, Garcia said the tracks will soon be covered again. Workers have cleaned, mapped, measured and photographed tracks to monitor changes over time. The park is also mulling solutions that would allow the tracks to survive longer if they’re exposed again, according to Garcia.
Repeated cycles of exposure and covering-up can wear on fossils that would otherwise be protected by silt and sediment. Water flooding back into a dry area can erode rock and shoreline. Loose debris could bury or damage fragile specimens. Other fossils are at risk of being washed out by the advancing current. Intense storms pose similar dangers.
These threats are accelerating as climate change worsens, adding pressure on scientists and field workers to protect these finds before they are destroyed or swept away, said Santucci, of the Park Service.
Even if researchers can safely reach the ships, they’ll face a time crunch. In the short term, waters will return, reclaiming the sunken vehicles. In the longer term, rising and falling water levels driven by intensifying drought expose the metal structures to sunlight, rust-inducing oxygen and potentially volatile river conditions, all of which could affect their longevity.
“The flip side is that them being uncovered is an excellent opportunity for outreach, for the global community to understand history and see what only divers might have been able to see,” she said. “There’s going to be some destruction, but you also understand the importance of that public exposure.”
Buddhist statues built during the Ming and Qing dynasties cropped up on an island reef in the Yangtze, which is experiencing record-low water levels. In Spain, archaeologists were recently able to access an ancient monument known as “Spanish Stonehenge” in a Tagus River reservoir; it has seldom been visible since the area was flooded in the 1960s to build a dam. And in Iraq, the remains of a 3,400-year-old city came into view in June when drought sapped waters in a reservoir in the country’s north.
The fleeting view of these treasures comes at an enormous ecological cost. Drought ravages crops and strains livestock and native species. It worsens air quality and raises the risk of wildfires, among other environmental ills. As the planet warms, these cycles are all but certain to continue.
“We can look at it as a two-edged sword,” Santucci said. “We can document the adverse impacts of climate change but benefit from finding things that have been exposed due to the same factors.”
