It is this frozen condition that preserves the extraordinary organic materials — mammoth remains, ancient plant communities, and human artifacts and biological specimens — that make sites like Yana RHS so scientifically rich.

As global temperatures rise, permafrost is thawing.

In some parts of Siberia, the active layer — the surface zone that freezes and thaws with the seasons — is deepening year by year, penetrating into ground that has been continuously frozen for tens of thousands of years.

The organic material that has been preserved by that long freezing is exposed, for the first time in millennia, to the microbial activity and chemical processes that decompose organic matter.

The result is a race between discovery and decomposition.