The origin of Lake Cheko and the 1908 Tunguska Event recorded by forest trees

Several lines of evidence indicate that Cheko, a small lake close to the epicentre of the 1908 Tunguska Event (TE), fills a crater left behind by a fragment of the Tunguska Cosmic Body that impacted the ground downrange of the main explosion. It is thought that over 80 million trees were flattened or burnt as a consequence of the TE. However, a small number of trees in the devastated area survived the explosion and recorded in their growth-ring patterns the environmental changes that followed this event. Some of those trees were found around Lake Cheko, similar to 10 km NW of the inferred TE epicentre. We analysed new data from the floor of Lake Cheko, including seismic-reflection profiles, side-scan sonar and video images, as well as dendrochronological evidence in tree samples collected along the shores, to test the hypothesis of a 1908 formation of the lake.