From: Terra Nova, Vol. 20, Issue 2 (April 2008) © Blackwell Publishing Ltd.

Fig. 3 Morphobathymetric map of lake Cheko: (a) bathymetry below 5 m water depth; and (b) bathymetry including the lake’s shorelines. Gray area in a), to the east of the eastern shore, marks the difference between the -5 m contour and a best-fit ellipse centred on the lake’s major axis.

The lake appears to be very asymmetric (elongated in a NW-SE direction) if we consider its geometry at water level. However, if we consider a level of just 5 meters below the surface, the lake’s morphology is similar to that of a funnel or of an inverted cone. Most of the apparent ellipticity is caused by a very shallow (<2 m depth) area that extends onto the southeastern side of the lake. The nature of the target could also have contributed to the crater asymmetry, because the NE shore of the lake is bounded by a doleritc hill, where the alluvial deposits of the Kimchu valley pinch out. This could have limited the post impact growth of the Cheko crater towards the E (Figs 1 and 3).

To download a higher resolution image click here: 545 kb.

Back to the Terra Nova file

Back to the Photo Gallery

Back to the Tunguska Home Page