Tsunamis have claimed hundreds of thousands of lives in the past two decades. Now a new study finds that a 6,000-year-old skull may come from the earliest known victim of these killer waves.
The partial human skull was discovered in 1929 buried in a mangrove swamp outside the small town of Aitape Papua New Guinea, about 500 miles north of Australia. Scientists originally thought it belonged to an ancient extinct human species, Homo erectus. However, subsequent research dated it to about 5,000 or 6,000 years in age, suggesting that it instead belonged to a modern human.
The skull is one of just two examples of ancient human remains found in Papua New Guinea after more than a century of work there. As such, archaeologists wanted to learn more about this skull to elucidate how people settled this region.
The scientists went back to where this skull was found and sampled the soil in which it was discovered. They focused on details such as sediment grain size and composition.
In the sediment, the researchers discovered a range of microscopic organisms from the ocean known as diatoms. These were similar to ones found in the soil after a 1998 tsunami killed more than 2,000 people in Papua New Guinea — for instance, their shells of silica were broken, likely by extremely powerful forces.
These diatom shells, combined with the chemical compositions and the size ranges of the grains, all suggest that a tsunami occurred when the skull was buried. The researchers suggested the catastrophe either directly killed the person or ripped open their grave.
Tsunamis, which are giant waves caused by earthquakes, volcanic eruptions or underwater landslides, are some of the deadliest natural disasters known. The 2004 tsunami in the Indian Ocean killed more than 230,000 people, a higher death toll than any fire or hurricane.
The site where the skull was found is currently about 7.5 miles away from the coast. Still, the researchers noted that back when whoever the skull belonged to was alive, sea levels were higher, and the area would have been just behind the shoreline.
The waves of the tsunami that hit Papua New Guinea in 1998 reached more than 50 feet high and penetrated up to three miles inland. “If the event we have identified resulted from a similar process, it could have also resulted in extremely high waves,” study co-lead author Mark Golitko, an archaeologist at the University of Notre Dame in Indiana and the Field Museum in Chicago.
These results show “that coastal populations have been vulnerable to such events for thousands of years,” Golitko said. “People have managed to live with such unpredictable and destructive occurrences, but it highlights how vulnerable people living near the sea can be. Given the far larger populations that live along coastlines today, the potential impacts are far more severe now.”
Golitko plans to return to the area over the next few years “to further study the frequency of such events, how the environment changed over time, and how people have coped with the environmental challenges of living in that environment.” He and his colleagues detailed their findings Wednesday in the journal PLOS One.