Kronotsky Nature Reserve Kronotsky Nature Reserve Kronotsky (Кроноцкий) Nature Reserve (also: "Kronotsky Biosphere Zapovednik") is a nature area reserved for the study of natural sciences in the remote Russian Far East, on the coast of the Kamchatka Peninsula. It was created in 1934 and its current boundary contains an area of . The largest lake in the reserve is Lake Kronotskoye, which covers an area of . It also has Russia's only geyser basin, plus several mountain ranges with numerous volcanoes, both active and extinct. Due to its often harsh climate and its mix of volcanoes and geysers, it is frequently described as
Extinct radionuclide Extinct radionuclide An extinct radionuclide is a radionuclide that was formed by nucleosynthesis before the formation of the Solar System, about 4.6 billion years ago, and incorporated into it, but has since decayed to virtually zero abundance, due to having a half-life shorter than about 100 million years. Short-lived radioisotopes that are found in nature are continuously generated or replenished by natural processes, such as cosmic rays (cosmogenic nuclides), background radiation, or the decay chain or spontaneous fission of very long-lived isotopes such as uranium or thorium. Short-lived isotopes that are not generated or replenished by natural processes are not