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15

I think you are confused about the timescales and the magnitude of the impact that is being talked about here. The collision between the early Earth and a roughly Mars sized body, Theia is thought to have happened between 4.4 and 4.45 billion years ago. The Pangaea supercontinent had fully assembled by around 250 million years ago. Previous to this there ...


11

The linked paper does numerical modelling of a hypothetical tsunami and predicts speeds between 60 m/s (at its point of origin) and 30 m/s (nearer to shore). We can try a back-of-an-envelope approximation to see if we get close, and to understand why the speed would be so much lower than on Earth. A tsunami behaves as a gravity wave with a very long ...


4

The volume of a sphere is $\small\sf{\frac4 3\pi R^3}$, where $\small\sf{R}$ is the radius. The volume of Earth with the 4 cm deep iridium rich layer is, $\small\sf{V_{Ei} = \frac 4 3\pi (6.378\cdot10^6)^3}$ $\small\sf{m^3}$ = $\small\sf{1.086 \ 781 \cdot 10^{21}}$ $\small\sf{m^3}$ The volume of the 4 cm deep iridium rich layer is, $\small\sf{V_i = \frac ...


4

A 10 km asteroid would not only obliterate the section of glacier it hit, but also create a huge crater at the impact site! The asteroid that created the Vredefort crater in South Africa is estimated to have been 10 to 15 km in diameter. It is also estimated that the initial crater created by the impact, some 2 billion years ago before it was eroded, was ...


4

Several possible ways.. Stratigraphic (Local): If the crater has been buried, just date the first rocks that are on top of the crater but not disturbed by it; this can be done using fossil-based dating if no good radiometric techniques are available. This has the advantage of being unambiguous, but the problem could be, especially for land based craters, ...


3

There are micro-tectites galore, strewn over thousands of square kilometres. But remains of the actual bolide? Hard to say, because the impact crater is now buried under 600 metres of sediment. Earlier this year the joint IODP-ICDP drilling program drilled to a depth of 1300 metres. As far as I know, their findings are not published yet.


2

Welcome to StackExchange SE! I don't think I fully understand your question, but I'll try to answer it. Reanalysis data is the use of weather models and data assimilation to piece back the weather. It is a 4-dimensional dataset (Latitude, longitude, pressure levels, and time). You can do whatever you wish with that data (provided you follow the legal ...


2

A Korean here. Haean Myeon in Gangwon-do has two theories of creation. One is Meteor impact and another is differential erosion. There were no meteor related evidence found at Haean so the erosion theory is more agreed upon at the moment. Direct translation from introduction website for Hae An: According to the analysis of the granite of the punchbowl ...


1

Vredefort No extraterrestrial iridium anomaly: http://adsabs.harvard.edu/full/1989LPSC...19..733F I'm not sure I fully agree with them, because there is quite a lot of Ir there and their threshold of 200 pg/g seems somewhat arbitrary to me. They claim the Ir was derived from local rocks, but that's a hell lot of iridium! Sudbury There is an an iridium ...


1

A 5km impactor would make a very, very global mess. Here's a discussion of tsunami formation from asteroid impacts. It presents numbers for impactor size up to 2km, and posits a rule-of-thumb that indicates a 5km impactor would generate a coherent wave (one that doesn't dissipate much over great distances) as long as it impacts in water less than 20-30km ...


1

Dust would not have to be chemically poisonous to render air unbreathable but a big impact would first of all release a blast of hot plasma that nothing nearby will survive with accompanying air blast. Dust would be mostly from Earth material and that will vary in chemistry according to what is locally present; the Chicxulub (dinosaur killer) impact hit ...


1

tl;dr while the docudrama is over-dramatised, yes, this is possible. Simply put, we already have processes which do make air unbreathable in small or even large areas, from dust or poisonous gases. Typically these are volcanic in origin, with fine dust from some volcanoes causing breathing difficulties across large areas, and from gases (often sulphur-...


1

Disclaimer: I haven't watched the docudrama. For a comet impact, I think the chemical effects (dumping poisonous gases into the atmosphere) would be completely overwhelmed by the thermal effects (lots and lots of kinetic energy converted to heat). Those poisonous gases would surely be converted to plasma and/or blasted out in the shockwave from the impact. ...


1

That doesnt seem realistic since eventually all the dust from all the volcanic activity, as well as that caused by our doing, eventually makes its way back down to earth. Most dust particles end up being soaked up by earths cloud layer coming down in rain. I have to agree with Gimelist but volcanism can and has produced conditions you mentioned by expelling ...


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