A group of researchers led by Hardy Pfanz, a Professor from the University of Duisburg-Essen has finally solved the mystery surrounding the ancient mass deaths in Denizli, Turkey, notoriously known 'Gate to Hell'.
The area also renowned as 'Hades' Gate' is named after Hades, the Greek God of the underworld. Many ancient tales claimed that people would drop down dead once they enter Roman-Greco grotto in the ancient ruins of Hierapolis.
Now the new study has finally unveiled the mystery behind the unexplained mass deaths which happened during the ancient ages. The researchers found that Roman-Greco grotto is sitting in the above the Badadag fault line, which indicates that toxic gases including carbon dioxide might have escaped from the earth's crust and filled the grotto. According to experts, seismic activities in the area are responsible for this strange phenomenon. The study report is published in journal Archaeological and Anthropological Sciences.
"Two thousand years ago, only supernatural forces could explain these phenomena from Hadean depths whereas nowadays, modern techniques hint to the well-known phenomenon of geogenic CO2 degassing having mantle components with relatively higher helium and radon concentrations," wrote the researchers in the study report.
The researchers also revealed that carbon dioxide was found to be at deadly concentrations of up to 91 percent in a grotto below the temple of Pluto. The study report made it clear that this amount of carbon dioxide is enough and more to kill birds, insects, and mammals.
"Our measurements confirm the presence of geogenic CO2 in concentrations that explain ancient stories of killed bulls, rams, and songbirds during religious ceremonies. They also strongly corroborate that at least in the case of Hierapolis, ancient writers like Strabo or Plinius described a mystic phenomenon very exactly without much exaggeration," added the researchers.
In the ancient days, bulls were sacrificed in the vapor-filled cave, an act to please Hades, the underworld god and the brother of Lord Zeus. Ancient people believed that the grotto was filled with the deadly poisonous breath of Hades. According to Greek mythology, Hades is responsible for looking after the dead people, and to rule the underworld.