Visualization and Interpretation in 3D Virtual Reality of Topographic and Geophysical Data from the Chicxulub Impact Crater

We have assembled Shuttle Radar Topography Mission (SRTM) data (Borst and Kinsland, 2005), gravity data (Bedard, 1977), horizontal gravity gradient data (Hildebrand et al., 1995), magnetic data (Pilkington et al., 2000) and GPS topography data (Borst and Kinsland, 2005) from the Chicxulub Impact Crater buried on the Yucatan Peninsula of Mexico. These data sets are imaged as gridded surfaces and are all georegistered, within an interactive 3D virtual reality (3DVR) visualization and interpretation system created and maintained in the Center for Advanced Computer Studies at the University of Louisiana at Lafayette. We are able to view and interpret the data sets individually or together and to scale and move the data or to move our physical head position so as to achieve the best viewing perspective for interpretation. A feature which is especially valuable for understanding the relationships between the various data sets is our ability to "interlace" the 3D images. "Interlacing" is a technique we have developed whereby the data surfaces are moved along a common axis so that they interpenetrate. This technique leads to rapid and positive identification of spatially corresponding features in the various data sets. We present several images from the 3D system, which demonstrate spatial relationships amongst the features in the data sets. Some of the anomalies in gravity are very nearly coincident with anomalies in the magnetic data as one might suspect if the causal bodies are the same. Other gravity and magnetic anomalies are not spatially coincident indicating different causal bodies. Topographic anomalies display a strong spatial correspondence with many gravity anomalies. In some cases small gravity anomalies and topographic valleys are caused by shallow dissolution within the Tertiary cover along faults or fractures propagated upward from the buried structure. In other cases the sources of the gravity anomalies are in the more deeply buried structure from which faults or fractures have propagated upward leading to enhanced dissolution and topographic valleys. In addition, our ability to analyze the data in detail in 3D has allowed us to interpret several cuspate slump features around the margin of the major collapse, which are similar to those seen around the margins of craters on other solar system bodies.