
Eltanin impact - zeristor
https://en.wikipedia.org/wiki/Eltanin_impact
======
nerdponx
It's interesting to see how they estimate all the different quantities
involved here: first the fact that there was an impact at all, then the size
of the impactor and its speed, then the size of the crater and the ensuing
environmental effects like the height of the resulting tsunami, ozone
depletion, etc. But there is apparently no evidence of a major extinction
event at the same time.

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?

I'm not trying to cast specific doubts on this study or any other particular
one, just wondering in general how confident these kinds of ancient geological
results are.

~~~
abathur
> 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-2111G...](http://www.geosci.usyd.edu.au/users/prey/Teaching/Geos-2111GIS/Ref/Ward-
TsunamicImpact.pdf) (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/S0012821X1...](https://www.sciencedirect.com/science/article/pii/S0012821X14006773)
(2015)

------
jessriedel
Tangential: Anyone know how to fix the {{Location map}} template on this page?
It doesn't have the proper border around it, and the text runs too close to
the image.

When I look at the template page, this problem doesn't appear, but I don't
know why:
[https://en.wikipedia.org/wiki/Template:Location_map](https://en.wikipedia.org/wiki/Template:Location_map)

