MORPHOLOGY OF LAKES OF THE CENTRAL TUNGUSKA PLATEAU (SIBERIA, EVENKIA): NEW INFORMATION ON THE PROBLEM OF THE “TUNGUSKA EVENT 1908”

Abstract

The bottom morphology and thickness of bottom sediments of lakes Zapovednoye and Peyungda were studied by echo-sounding and seismic reflection profiling. The lakes are located in 60 km and 50 km from inferred explosion epicenter of “Tunguska event 1908”, respectively. We showed that both lakes have circular shape and funnel-like morphology with 60 and 34 m maximum water-depth, respectively, close to their geometrical centers. The shape of the lake is similar to famous Lake Cheko which is believed to be a secondary impact crater for Tunguska event of 1908. The shape of Lake Cheko was suggested to be highly unusual that was one of arguments to support the hypothesis of impact origin of Lake Cheko. We have shown that lakes Zapovednoye and Peyungda are examples of funnel-like deep lakes, and the age of both lakes exceeds are two thousand years. Therefore, we assume that all three lakes are most likely of karst origin. The similarity of the shape of the three reservoirs and their location in the riverbeds indicate the similar origin and testify against the hypothesis of the impact origin of Lake Cheko in 1908.