For almost 15,000 years, a glacier found on the northwestern Tibetan Plateau of China was found to be home to many viruses frozen in time, and many of them were unknown to modern science.
Scientist recently inspected two ice cores from this Tibetan glacier and revealed the existence of 28 never-before-seen virus groups. Scientists hope that by analyzing these mysterious viruses could help researchers learn about which viruses thrive in different climates and environments over time.
“However, in a worst-case scenario, this ice melt [from climate change] could release pathogens into the environment,” the researchers wrote in the study, which has not yet been peer-reviewed. If this happens, it’s best to know as much about these viruses as possible, the researchers wrote.
It can very challenging to study ancient glacial microbes. This is due to how extremely easy it is to contaminate ice core samples with modern-day bacteria. Researchers had to create a new protocol for an ultraclean microbial and viral sampling.
The two ice core samples taken from the Guliya ice cap on the Tibetan Plateau were collected in 1992 and 2015. There were not any special measures taken to avoid microbial contamination during drilling, handling, and transporting of the core. This meant the exterior of the ice cores were contaminated, but the insides were still perfectly intact.
Researchers had to take special measures to not contaminate the insides of the core. The researchers careful measures revealed 33 groups of virus genuses in the ice cores. 28 of these were unknown to science. “The microbes differed significantly across the two ice cores,” the researchers wrote in the study, “presumably representing the very different climate conditions at the time of deposition.” It’s no surprise that the glacier held these mysterious viruses for so long, researchers said.
“We are very far from sampling the entire diversity of viruses on Earth,” Chantal Abergel, a researcher in environmental virology at the French National Centre for Scientific Research, who wasn’t involved with the study.