Figure 2 of the A. Ol'khovatov's
article on the 1908 Tunguska event (see explanation below)
The time-sequence of reports about earthquakes (vertical lines) in
the Lake Baikal region from March 1908 (3) to November 1908 (11) taken from
a catalog of earthquakes. The seismic manifestations attributed to the Tunguska event are
marked by enlarged height of the vertical line.