> apparently no evidence of a major extinction event at the same time Not a scientist, but I did notice Wiki has a sidebox that gives some very rough indicator

> apparently no evidence of a major extinction event at the same time Not a scientist, but I did notice Wiki has a sidebox that gives some very rough indicator of the confidence about this hypothetical impactor. It also lists its estimated size as 1-4km compared to the 11-81 it lists for the confirmed impactor at Chicxulub (https://en.wikipedia.org/wiki/Chicxulub_crater https://en.wikipedia.org/wiki/Chicxulub_crater), or around 1/3-1/20th of the size. I don't know the impact (sigh) of these factors, but it's probably worth noting that this is also a deep ocean (5km) impact 1500km offshore near the antarctic circle with continents in roughly contemporary locations, versus a continental shelf impact (perhaps sloping from 100m to 1.2km) near the tropics when the landmasses that comprise Africa, the Americas, Europe and Asia are thought to have been much closer together than they are today. > How carefully do researchers in this field crosscheck these numbers? Do they build their next model assuming that the previous model got it right? Or did someone run through some kind of conservation-of-energy calculations and say "yep it all fits together"? I assume these kinds of things are researched all at once soon after the discovery, but are those results ever revisited? Again shooting from the hip, but I don't think it usually works out like this. AFAIK it's rare to have a proposed significant impact that doesn't attempt to marshal/explain existing observations of various sorts locally, regionally, and globally. Likewise, the proposal is likely to get refuted or revised as others point out, publish, and discover something that seems to refute or support the proposed impact. Part of demonstrating the validity of a new model (or improvements to an old one) is going to be showing that it can better-explain some observations without creating large inconsistencies. I went looking for papers on the associated tsunami to see how they change over time, but you may want to go straight to this one (https://onlinelibrary.wiley.com/doi/full/10.1111/maps.12326 https://onlinelibrary.wiley.com/doi/full/10.1111/maps.12326) from 2014. I think it's really well written, and does a decent job of unpacking the various factors that go into how they are projecting some of the various quantities involved. Here are a few of the others: http://www.geosci.usyd.edu.au/users/prey/Teaching/Geos-2111GIS/Ref/Ward-TsunamicImpact.pdf http://www.geosci.usyd.edu.au/users/prey/Teaching/Geos-2111G... (2002) https://link.springer.com/article/10.1134/S0038094607010066 https://link.springer.com/article/10.1134/S0038094607010066 (2007) https://onlinelibrary.wiley.com/doi/abs/10.1002/jqs.2571 https://onlinelibrary.wiley.com/doi/abs/10.1002/jqs.2571 (2012) https://www.sciencedirect.com/science/article/pii/S0012821X14006773 https://www.sciencedirect.com/science/article/pii/S0012821X1... (2015)