The crater tied to the end of the dinosaurs is buried under a kilometre of rock. You can still find its edge on a map, because the limestone above it collapsed into an arc of water-filled pits.
165 km
diameter of the Cenote Ring, ± 5 km. Mapped from Landsat imagery, 1993.
Map is schematic: coast hand-simplified, cenote dots illustrate the pattern and are not surveyed positions. Peak ring drawn through the drill site.
~1 kmof younger rock buries the crater. Nothing on the surface looks like an impact.
66.04million years since impact, dated to ± 11,000 years.
~75%of plant and animal species died in the extinction it marks.
~10 kmwide: the rough size of the asteroid, steep from the northeast.
01 · The ring
A circle nobody drew
The sinkholes cluster in an arc over slump faults at the buried rim, where the limestone above gave way.
1981Penfield and Camargo report a buried arc from Pemex survey data.
1991Hildebrand and colleagues identify it as the end-Cretaceous crater.
1993Pope, Ocampo and Duller map the Cenote Ring on Landsat imagery.
1995Gravity data line up with the cenotes: about 180 km across.
2016IODP drills 1,335 m into the peak ring.
02 · The size
One crater, six diameters
The ring is the sharpest feature, but the crater’s size depends on which structure you measure.
Published estimates, not a measurement series. The range runs from 150 to about 300 km.
03 · The core
Granite 750 metres down
This granite began 8–10 km down in the crust. The impact lifted it to within about 750 metres of the seafloor.
Hole M0077A, IODP Expedition 364 (2016). Depth in metres below seafloor. Chicxulub is the only crater on Earth with an unequivocal peak ring.
04 · The aftermath
From minutes to decades
The first waves were modeled at kilometres high. The cold that followed lasted far longer.
Log time scale. Every point before “+66 million yr” is modeled. Wave height: Range et al. 2022. Temperature: Brugger et al. 2017.
Three versions of the cold
Modeled global cooling depends on how long sulfate aerosols stayed in the stratosphere.
1.5 kmwave height 10 minutes after impact, modeled
30,000×the energy of the 2004 Indian Ocean tsunami, modeled
100+ mwaves on Gulf of Mexico coasts, modeled
05 · The rank
Second largest, and the youngest of the top three
Older giants have been eroded and deformed. This one was buried and preserved.
Earth Impact Database diameters, in which Chicxulub is 150 km. Age in millions of years. *Database lists 64.98 Ma; refined to 66.04 Ma by Renne et al. 2013.
06 · The wells
The ring is also the plumbing
Yucatán has no surface rivers, so the crater’s scar now steers the water people drink.
The ring has been proposed to act as an underground river, concentrating groundwater and carrying it to the coast near Celestún and Dzilam de Bravo.
71%of the aquifer rated high to extreme vulnerability
2.7%of wastewater treated before returning underground
Counts and percentages are press-reported (Por Esto!, 2026). Earlier reports give 2,241–3,200 registered cenotes.
What to notice on the map
Read the dots, then the coast
It is half a circle.
The dots stop at the shore. The centre sits on the coast, so the other half lies under the Gulf.
Mérida is inside it.
The state capital sits within the ring, close to the crater’s centre.
The ring meets the sea at two points.
Springs near Celestún and Dzilam de Bravo are where its water is proposed to come out.
Why it matters.
Water moves through this fractured limestone with little filtering, so pollution can reach the only drinking water most people here have.