Source: AGU Advances
Tsunamis most often happen when the seafloor is displaced by earthquakes. However, tsunami waves can also be produced by rare asteroid strikes in the oceans (~3% chance of 2-meter waves per millennium, as described by Ward and Asphaug ). Range et al.  modeled the tsunami expected when the Chicxulub asteroid crashed into the sea about 66 million years ago near the Yucatan Peninsula of Mexico, creating one of the largest confirmed impact structures on Earth. The authors found that the Chicxulub impact may have generated global tsunami waves that were 30,000 times more energetic than any we have ever observed. The models show particularly strong waves more than 10 meters in height striking shorelines in the north Atlantic and south Pacific regions. The authors find support for their models from observations of gaps and/or disturbances in seafloor sedimentary records from this time. They note many complexities associated with asteroid impacts in the oceans that require further model refinements to gain a more complete understanding of these rare but calamitous events.
Citation: Range, M., Arbic, B., Johnson, B., Moore, T., Titov, V., Adcroft, A. et al. The Chicxulub Impact Produced a Powerful Global Tsunami. AGU Advances, 3,e2021AV000627. https://doi.org/10.1029/2021AV000627
—Tom Parsons, Editor, AGU Advances