Solid Earth Discussions www.solid-earth-discuss.net 1869-9537 2 1 2010 10.5194/sed-2-69-2010 http://www.solid-earth-discuss.net/2/69/2010/ http://www.solid-earth-discuss.net/2/69/2010/sed-2-69-2010.html http://www.solid-earth-discuss.net/2/69/2010/sed-2-69-2010.pdf 69 103 2010-03-09 Candidates for multiple impact craters: popigai and chicxulub as seen by EGM08, a global 5'×5' gravitational model J. Klokočník jklokocn@asu.cas.cz J. Kostelecký I. Pešek P. Novák C. A. Wagner J. Sebera Astronomical Institute, Academy of Sciences of the Czech Republic, Czech Republic Research Institute for Geodesy, Topography and Cartography, Czech Republic Department of Advanced Geodesy, Czech Technical University, Czech Republic Department of Math, Faculty of Applied Sciences, University of West Bohemia, Czech Republic Laboratory for Satellite Altimetry, NOAA, USA In 2008 the new Earth Gravitational Model (EGM08) was released. It contains a complete set of spherical harmonic coefficients of the Earth's gravitational potential (Stokes parameters) to degree 2190 and order 2159 that can be used for evaluation of various potential quantities with both the unprecedented accuracy and high spatial resolution. Two such quantities, the gravity anomaly and second-order radial derivative of the disturbing potential, were computed over selected areas with known impact craters. The displays of these derivatives for two such sites clearly show not only the strong circular-like features known to be associated with them but also other symmetrical structures which appear to make them multiple impact sites. At Popigai, Siberia, the secondary circular features fall in a line from the primary in the SE direction. At Chicxulub, Yucatán, there appears to be one secondary crater close to the primary in the NE direction, as well as possibly others in the vicinity of the main crater. 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