The Chicxulub Impact Produced a Powerful Global Tsunami

• Published in: AGU advances Vol. 3; no. 5
• Main Authors: Range, Molly M., Arbic, Brian K., Johnson, Brandon C., Moore, Theodore C., Titov, Vasily, Adcroft, Alistair J., Ansong, Joseph K., Hollis, Christopher J., Ritsema, Jeroen, Scotese, Christopher R., Wang, He
• Format: Journal Article
• Language: English
• Published: Hoboken John Wiley & Sons, Inc 01.10.2022; Wiley
• Subjects: Chicxulub impact; Cretaceous; Flow velocity; impact; Marine sediments; Mass extinctions; Ocean floor; Paleogene; Propagation; Sediments; Shallow water; Simulation; tsunami; Tsunamis; Gulf of Mexico
• ISSN: 2576-604X; 2576-604X
• DOI: 10.1029/2021AV000627

The Chicxulub crater is the site of an asteroid impact linked with the Cretaceous‐Paleogene (K‐Pg) mass extinction at ∼66 Ma. This asteroid struck in shallow water and caused a large tsunami. Here we present the first global simulation of the Chicxulub impact tsunami from initial contact of the projectile to global propagation. We use a hydrocode to model the displacement of water, sediment, and crust over the first 10 min, and a shallow‐water ocean model from that point onwards. The impact tsunami was up to 30,000 times more energetic than the 26 December 2004 Indian Ocean tsunami, one of the largest tsunamis in the modern record. Flow velocities exceeded 20 cm/s along shorelines worldwide, as well as in open‐ocean regions in the North Atlantic, equatorial South Atlantic, southern Pacific and the Central American Seaway, and therefore likely scoured the seafloor and disturbed sediments over 10,000 km from the impact origin. The distribution of erosion and hiatuses in the uppermost Cretaceous marine sediments are consistent with model results. Plain Language Summary At the end of the Cretaceous, about 66 million years ago, the Chicxulub asteroid impact near the Yucatan peninsula produced a global tsunami 30,000 times more energetic than any modern‐day tsunami produced by earthquakes. Here we model the first 10 min of the event with a crater impact model, and the subsequent propagation throughout the world oceans using two different global tsunami models. The Chicxulub tsunami approached most coastlines of the North Atlantic and South Pacific with waves of over 10 m high and flow velocities in excess of 1 m/s offshore. The tsunami was strong enough to scour the seafloor in these regions, thus removing the sedimentary records of conditions before and during this cataclysmic event in Earth history and leaving either a gap in these records or a jumble of highly disturbed older sediments. The gaps in sedimentary records generally occur in basins where the numerical model predicts larger bottom velocities. Key Points The authors present the first global simulation of the Chicxulub impact tsunami Total energy present in the impact tsunami is much greater than for any modern‐day tsunami Impact tsunami flow velocities are strong enough to disturb and erode sediment in basins halfway around the globe