Yes, the Toba eruption 74kya, left a crater 18 by 50 or 60 miles (I couldn't find my reference just now but that is what I remember). One heck of an impact. Some scientists say it reduced the earth's human population of 5 or 10,000 individuals, and I think that includes Neanderthals, and obviously those new Flores folk.
While reading this post I came across the following; "A candidate for the reverse shock wave is the supernova remnant North Polar Spur, with an estimated age of 75,000 years and a distance of...424 light years,...locatd in the north sky from where it would have preferentially irradiated the Northern Hemisphere." At the time I thought now isn't that an interesting coincidence.
Is it possible that major cosmic energy bombardments, influence major volcanic and techtonic events here on earth? Jaggar in "Volcanoes Declare War," 1945, shows an interesting chart of Kilauea volcano in Hawaii in which he observes an apparent correlation between the maximum altitude of the lava pool with sunspot minima, p. 149.
It would be interesting if scientists would look at that, if they haven't already. Regarding a stepwise lowering of world temperatures from about 28,000 BP to 18,000 BP, one step occurred at 22,000 ya, and I find the Sakara-jima volcano in Japan blew out a caldera 15 miles in diameter. I am still looking for other smoking guns. This may have been the final blow to Neanderthals.
I have another "toba" right in my back yard so to speak : the Yellowstone super volcano, kitty corner across Montana. A 5+ richter earthquake hit it just a couple of years ago, kept quiet for obvious reasons, but something is definitely going on with it as the ground is rising FAST, as well as increased geothermal activity. There is a HUGE magma chamber below it and it's on the MOVE. Yellowstone super-blows about every 600,000 years and it's been 640,000 years since the last one(30+/- minor eruptions in between). If it's a MAJOR one it's nuclear winter(where oh where is global warming when you really need it).......Neanderthals have been intensely studied, they even think they can get their DNA somehow(jurassic park?)but all they have to do is get democrat's DNA for a perfect match. Actually the basques may be neanderthals(they supposedly died out on gibralter rock 19,000 years ago)as they are definitely a distinctly different people with a language unrelated to any other language......Interesting story about the runts on new Flores, evolutionary downsizing of the whole ecology on that island. Possible lessons for our time? Have you got your survival supplies ready for when IT happens? Whatever IT is....