(hope this is the right place to post this) I'm creating an inland sea in the Mojave Basin area using one of the Four Horsemen, a non-meteoric massive density star fragment. It will not be one giant hole in the ground. It will likely be dotted with islands and possibly have inland tidal estuaries. My topology skills etc are so bad! I can't make heads or tails out of that kind of stuff. I'd very much like to NOT mangle the Colorado or Rio Grande rivers. What issues or considerations come to mind on this idea?
If the meteor had a collection of smaller hitchhikers like the one that killed the dinosaurs, there would likely be numerous smaller pit-lakes scattered in the immediate area.
If this is due to an impact with a stellar fragment and we're not using freshwater sources, but instead a marine transgression to form the epeiric sea, when does your story take place? I ask because if the cause is an impact rather than tectonic activity, the Mojave Basin is not all that close to the coast. Just eyeballing it, it looks like it would require an impact as significant, if not more, than the Chicxulub crater that took out the non-avian dinosaurs.
Various factors will also have these objects colliding with each other, so I envision a mile-wide cut across Baja, and a series of impacts along a rough path from Sea of Cortes/Salton Sea/Death Valley/Salt Lake. I'm still unclear where the majority of it would accumulate. I assumed around Death Valley, but the maps just confuze the heck outta me. Such has it been since childhood. Oh, oops, it is a series of non-meteoric impacts across the globe, but I'm only focusing on the western region atm.
This might help your visualization: https://www.dw.com/en/worst-case-scenario-for-sea-level-rise-no-more-new-york-berlin-or-shanghai/a-18714345 There's an app from NOAA that allows you to fiddle with sea level rises on a map, but it only goes up to ten feet, which is the "realistic" number that NASA predicts for the next 100 years.
I'm surprised there's that much of Florida left. I'm thinking more of a channel into a hook above Death Valley, like an exclamation stroke or reverse comma. Err, maybe an inverted pear-shape with stem pointing west of the Colorado River? It would require a Class 3 terraformer to hit south of Great Basin and a series of Class 2 hits down through the Salton Sea, I think. It would be interesting to channel some water from the Salt Lake area. I have this notion of whales migrating through the desert.
Your best bet is probably an incredible military strike of never-before-seen calamitous power, or a meteoric cataclysmic event at least on par with that which wiped out all land-dwelling dinosaurs. Consider: https://www.businessinsider.com/air-force-rods-from-god-kinetic-weapon-hit-with-nuclear-weapon-force-2017-9 Of course, it would take hundreds of millions of even the "Tsar Bomba" to produce anything equivalent to the asteroid that hit the Yucatan. So more than likely, a military weapon is out of the running, outside of an antimatter bomb. And such a "large" amount of antimatter would take billions of years to acquire unless you want to use some sci-fi magic.
Yeah, I'm not looking for that level of destruction from a single impact. Smaller ones hit at the Mexican border, then up around the Salton Sea area and up the Mojave, with a major impact near Death Valley. That opens up a path for seawater to go... somewhere, probably Great Basin? Salt Lake? I can't hit Death Valley directly cause there's supposed to be a volcanic trench under it! I don't want a 500M year extinction event. I want a navigable body of water large enough to have a bit of effect on regional weather. I can't figure out where exactly it would go, other than I don't want to disrupt the Colorado River. Spoiler: projectiles Various sized impacts are distributed around the globe like a sweep of doom. There would be minimal heat, but quake-like behavior would be catastrophic. Density is the enemy. My projectiles are non-meteoric but dense as solar iron. The needle-shaped (crystal) impactors would penetrate rather than eject the crust. The Class 1 shards are only about as big around as a school bus in the middle and taper down at both ends as long as a football field. Class 1 = school bus - neighborhood relocation program. Class 2 = locomotive - small city killer. Class 3 = skyscraper - bye-bye Manhattan. Class 4 = Pale Horseman - punch a 500mi pond in Australia. (only 4 of those)
I buy it. Sounds like you're cooking with gas to me! Think of all the shit in Star Wars that makes absolutely no sense. Now think of how nobody gives a shit. Seeing as you're actually bothering to put significant effort into making this plausible, you should be totally fine.
Thanks. I got to a point where I'm like, "water can only go below sea-level." Still can't figure out how much surface area that is, even before I poke holes in the world. Wrey's map shows a lot of area. Hmmm.
Unless you use sci fi/magic and based on your descriptions, Your Four Horsemen would be extremely close to an extinction level event. You could not reasonably cut across upper Baja with a channel a mile wide. There’s a mountain range running down the peninsula. Regarding the Colorado, the easiest path for sea water would be up it, so it pretty much has to be destroyed. That irregular border between California/Nevada and Arizona is the Colorado. Sorry
To follow @KiraAnn’s point above, your story shouldn’t be dependent on a specific location. For instance, making the valley around Sacramento (30 feet elevation, open to the ocean) the location would be a realistic place to put an inland sea.
I'm not an astrophysicist, but it seems to me a star fragment hitting the Earth would irradiate everything around it.
I'll be sure not to create any extinction events. Damn mountain ranges spoil everything! : I will stubbornly not disturb the Colorado River. I also refuse to eat my asparagus! Um, No. No aliens. I need a large, navigable body of water in the Southwestern desert to change the ecology and provide limited alternate transportation. (say goodbye to the i15, i40, i10, and i8 hiways) They're a shattering of various fragments, from microscopic to a very few Class 4 (non-meteoric). They are umpteen quizillion years dead. Otherwise, we'd be pulled apart zillions of miles before impact, and there'd be no story. Viserion's xenomorphic aliens can write that story. Sorry, no radiation, this time. .
Now I’m really curious about the story. Why the desert Southwest? Why not the Central Californian Desert? I’m not saying you don’t have good reasons, I’m just asking.
I'm destroying all land transportation south of I80 and creating a Mediterranean-ish weather cycle. If Mike can have his dinosaur island, I get my inland sea. Heh he
Earthquake and volcano combination. Then a few years (~10) of the world recovering. During that time of chaos and confusion, the world political landscape changes...
Yes. Also, what the hell is a "star fragment"? Stars are giant balls of plasma, if you pull some of it off, you'll just get another, small star (or a brown dwarf or planet.) Gravity will mold it back into a nearly perfect sphere and crush it's core into fusion. If it's too small, it'll simply evaporate, and if it's big enough to stay as one object, it'd be way way bigger than earth, it'd simply swallow the Earth with barely a hiccup. Neptune is one of the smallest gas giants that we know of, and it could hold more than 50 earths in it. Which sounds huge, but 25,000 Neptunes could fit into our relatively average star. No stars are cool enough to emit microwaves, even the coolest stars have surface temperatures around that of boiling water and will glow with a dull infrared. The only theoretical type of "star" that would generate mostly microwaves is called a black dwarf, and the universe simply isn't old enough for these to exist yet. No, at least not anymore than a planet. The core of a star is still mostly hydrogen, even after most of it's life. Stars cores simply aren't hot enough to produce anything close to radioactive elements, they are thousands of times too cold. Heavy elements are made by the ultra violent deathrows of a supernova, where the core temperature skyrockets, as well as in collisions of other non-stellar large objects like neutron stars. A tear in the Earth's crust of that magnitude only happened once in geological history. It spewed so much toxic crap into the air that it caused one of the five great extinction events in our history, killing about 95% of all species on Earth. It spewed so much methane and CO2 into the air that the sudden rise in Earth's temperature makes our current global warming look tame. 10 years is way too fast, last time, it took about 10 MILLION years for the planet to settle back down. I'm not sure you could so dramatically change the landscape without some ridiculously huge cataclysm. Most of the holes in planet Earth were formed mostly by ice over thousands of years, like the great lakes.
Yeah, this is drama, not sci-fi. I'm taking creative liberty with the crystalline iron formed in late stages. Out of probability of 4oobillion objects bouncing around, at any given moment, some of this material could be knocked out to pay us a visit. It's more about density and needle shape at non-meteoric velocity. I don't want to bore the reader with physics, anyway. I'm liquifying and pushing stuff around with millions of small penetrations, not vaporizing it. Yes, the experience will be more like earthquakes and waves of debris and skyscrapers surfing on them. It's a short romp at the beginning, with serious social issues thereafter.