Background colourmap shows Bouguer gravity anomaly map in the vicinity of the crater (gravity data courtesy of Hildebrand and Pilkington). The red circle marks the nominal position of the crater centre; the green circle marks the centre of maximum mantle uplift; the blue circle marks the centre of the peak ring (as defined by the annular gravity low surrounding the central high); the white triangle marks the location of the Expedition 364 drill site through the peak ring (Hole M0077A). The coastline is displayed with a thin white line; cenotes and sinkholes with white dots, and the city of Mérida with a white square. The dotted lines offshore mark the approximate location of the inner crater rim and the extent of faulting as imaged by seismic data14. Inset depicts the regional setting, with red rectangle outlining the region shown in the gravity map. Adapted from ref. 14.