Lovely. I've spent some amateur time chewing over how long the salt would have been manageable without the massive modern drainage driven undermountain to the sea.
That is super cool. Thanks for posting it!
I swear I posted OP months ago but returning search results is not the revealed purpose of the blog.
1: Pretty please say more!
I visit Mexico City about eight years ago. One thing that impressed me is that is has an absolutely perfect climate.
I swear I posted OP months ago but returning search results is not the revealed purpose of the blog.
I thought it had been posted before, but wasn't sure by whom, and couldn't find it either.
As soon as I read the title, Istanbul not Constantinople started playing, so well done.
I knew that it was on old lake bed - it's really important for earthquakes and building response, so I picked it up in engineering - but hadn't imagined the city as anywhere near as extensively lake as the images.
I read about Cortez and how amphibious his fighting was.
I have this fantasy about mighty raised-bed-agriculture-based city states rising from Lake Chad.
5: Really? Twist my arm!
SO the Valley of Mexico is modestly unusual, in geological terms, because it was big and endorheic: it didn't have any drainage to the sea. Water left by evaporation. If it rains more than it evaporates, these turn (in geological time) into locked seas. If it evaporates more than it rains, playas and deserts.
But the other thing about evaporation is that it doesn't remove salts ( NaCl or other). All water moving through soil or even over rock tends to pick up a little salt. The water coming into the Valley of Mexico was pretty salty-minerally to start with because of the geology (hot springs dissolve minerals better, and probably just the nature of the rocks). Soo... closed seas with salty inputs get saltier and saltier, and closed basins that dry out often turn into salt flats.
One side of Lake Texcoco was naturally too salty to grow crops in, and one of the things the cities did was maintain a dike between salt and fresh water (allowing them to occasionally flush the city side with fresh water).
Picture with the big dike:
https://en.wikipedia.org/wiki/Lake_Texcoco#/media/File:Basin_of_Mexico_1519_map-en.svg
So the amateur fat-chewing was, what are the limits to this? Assuming rain and evapotranspiration stay about the same, can you just... keep saltifying the salty side? It would turn into intensely weird mud and be awful during any drought long enough to raise dust-storms out of it, but... people will put up with that?
Ironically, what bothered industrial civ was not the salt but the floods, so Mexico between the 1960s and 2019 (!) built huge deep drainage tunnels... one of which is salting up the neighboring state that receives the water, apparently.
All water moving through soil or even over rock tends to pick up a little salt.
Because people drop potato chips.
I like my basins like I like my women, endorheic and restrained by a large dike.
I think 13 may be the smuttiest thing Moby has ever posted here. (Applause)
Thanks, but I liked the Hispanic-serving one better.
intensely weird mud and be awful during any drought long enough to raise dust-storms out of it, but...people will put up with that?
Well, 9 million people put up with the air quality in Mexico City today, so...yes?
Also, if the drought were bad enough to dry out the deepest part of the basin, where the salt was, I'm thinking they would have had worse problems than air quality anyway.
But really, this is fascinating. I knew about the lakes and causeways and chinampas but hadn't known it was endorheic. Hydrology:
Before the 20th century, the Mexico City portion of the valley contained a series of lakes, with saline lakes to the north near the town of Texcoco and freshwater ones to the south.[8] The five lakes, Zumpango, Xaltoca, Xochimilco, Chalco, and the largest, Texcoco used to cover about 1,500 km2 (580 sq mi) of the basin floor.[3] Small mountains such as the Sierra de Guadalupe and Mount Chiconaultla partially separated the lakes from each other.[23] All the other lakes flowed toward the lower Lake Texcoco, which was saline due to evaporation.Salinity sketch.
[...]
During the Aztec Empire, the northern lakes were inaccessible by canoe during the dry season from October to May.
In Canada, people just carried their canoes over dry bits.
Before the invention of gravy, Mexican food must have been so much better.
fresh water poured in from Lake Chalco and Xochimilco's freshwater springs, and the thermal springs of Zumpango and Xaltocan, as well as some in Texcoco itself, provided saline water.[3] During periods of high water levels--typically after the May-to-October rainy seasons--the lakes were often joined as one body of water [...] In the drier winter months the lake system tended to separate into individual bodies of water [...] Lake Texcoco was the lowest-lying of all the lakes, and occupied the minimum elevation in the valley so that water ultimately drained towards it.I wonder if they could have built dikes around the deepest parts of the basin further to limit mixing of fresh and salt during the wet season. Or maybe the actual dikes were the limits of that approach.
They were also producing salt around Lake Texcoco. So they were actually taking salt out while nature brought it in (even if some of it would eventually get back to the lake via sewage). On sufficient scale I'd guess that might have kept salinity under control indefinitely; maybe they actually hit that balance just through their natural salt demand.
And maybe the gold prize would have been diverting the east bank tributaries of Texcoco south to Lake Chalco. A contour canal on about this line? As you see it's flat enough for straight roads the whole way. About 40km, but hey, major earthworks is what they did.
It says I can borrow if from the nearby WVU library at Parkersburg.
For me it says Concordia University of Edmonton.
There's probably a Concordia University closer to me.
My son is playing a game called "Sisyphus" and legit wondering why he can't get the rock to the top.
Maybe I shouldn't have worried when he was talking about going to college in Ohio?
This is my second night of the same dance recital. There are little video vignettes in between each dance, featuring the dancers in the next dance. Most are tik-tok style or faintly funny. But the one where each of the 16 dancers shares their favorite bible verse - and the dance teacher does too! - definitely makes me feel uncomfortable.
I should say this is the high school dance recital, at the publicly funded public high school, as blessed by the Robert's court.
In this vignetter, the graduating seniors are giving advice to the lowerclass dancers. My favorite advice is to make memories. Make so many memories. It's so open to interpretation.
Watch out for the kid who picked Matthew 27:25.
I have this fantasy about mighty raised-bed-agriculture-based city states rising from Lake Chad.
...to which you've already devoted at least 1500 words, surely, just waiting for an audience?
Apparently no-one will read my book, so.
For me, Chaoyang University of Science and Technology in Taichung.
The author of that piece also takes some time to hype (and author) some books I am indeed not going to read, including an "an NFT story ... published on Twitter." So you clearly have options for how not to be read.
Equally fascinating are the alternate histories spinning out of this little item:During Hernán Cortés's siege of Tenochtitlan in 1521, the dams were destroyed, and never rebuilt, so flooding became a big problem for the new Mexico City built over Tenochtitlan.
Though the wiki is somewhat confused:After the destruction of Tenochtitlan in 1521, the Spaniards rebuilt the Aztec dikes but found they did not offer enough flood protection.
Presumably restoring the entire pre-conquest system would have been precluded by demographic collapse,* but:
1. Might the Spanish have imported slaves from Africa? (And along with the Africans perhaps certain diseases, with certain demographic consequences?*)
2. Might they have imported European settlers, from some intensively-cultivated swamplands like, IDK, the Spanish Netherlands? (Who might actually have survived, given, as Moby notes, the climate.)
3. Might they have introduced wet rice culture from the Philippines and/or West Africa (For fresh water and brackish!), or even (Hey, why not!) recession culture from Cambodia? (And presumably SE Asian settlers and diseases into the bargain!)
4. Might the Valley, so managed, have become the breadbasket of the Caribbean sugar islands? If so, with what consequences for Anglo North America?
5. How might the Valley, so managed, have affected the development of Mexican (or even Spanish Imperial) political culture?
*Do I trawl for teo? Why yes, I do.
I think once you kill all the local experts, you aren't going to get the thing to work again. Especially when the Spanish were trying to erase a culture.
They weren't trying to kill them off or erase their (material) culture. Indeed the demographic collapse was decidedly inconvenient for Spanish plans. More when I'm not on my phone.
The purpose of the system is what it does.
Okay, I have to go to bed soon but to quickly respond to a few of the points in 40:
Presumably restoring the entire pre-conquest system would have been precluded by demographic collapse
Not necessarily! The demographic collapse in the Valley of Mexico specifically was large but not permanent. The population reached a nadir in the early seventeenth century then began to grow, and it has been growing ever since. Not due primarily to immigration either; when reliable censuses started being taken in the eighteenth century they showed that the population of New Spain was still overwhelmingly Indian. The shift to a Spanish-speaking "Mexican" identity was a slow process over centuries involving both acculturation and intermarriage. This is not to say that enough specific people who knew how to manage the water-control systems actually did survive, of course, but it's far from impossible and the Spanish could have taken advantage of that expertise if they'd known about it. They didn't, of course, for whatever reason.
Might the Spanish have imported slaves from Africa?
They did! African slaves are attested in Mexico from the beginning of the Spanish presence. There wasn't as big a need for them as in other parts of the New World (see above about the limited and temporary demographic collapse), though, so the institution never really took root in Mexico and eventually faded away...
And along with the Africans perhaps certain diseases, with certain demographic consequences?
...but not before this, too, had its impact! The depopulation of the Gulf Coast especially was likely due to the introduction of malaria via African slaves, and the smallpox epidemic that enabled Cortes to conquer Tenochtitlan is traditionally thought to have been introduced by an African slave accompanying the expedition of Panfilo de Narvaez that the governor of Cuba sent to stop Cortes when he realized what he was doing. The sourcing on that story is actually pretty weak, but it makes epidemiological sense so I think there probably is something to it. Spanish adult men in this period would virtually all have survived smallpox in childhood, giving them immunity that would prevent them from transmitting it across the Atlantic. In Africa, however, smallpox was epidemic rather than endemic so it could have been, and likely was, transmitted to the New World via the slave ships.
Might they have imported European settlers, from some intensively-cultivated swamplands like, IDK, the Spanish Netherlands?
Maybe, but as noted above there wasn't actually much need for them. The Indigenous population of the Basin of Mexico did survive and continued to grow plenty of corn (especially for its much smaller size) as it gradually turned into a mestizo peasantry. Also I'm not sure the Spanish Netherlands (i.e., Belgium) have quite the same wetland reclamation experience as the Dutch ones but that's just a guess.
Might the Valley, so managed, have become the breadbasket of the Caribbean sugar islands?
Possibly, but I think transportation challenges would have made this hard. Grain is bulky and the roads weren't great. Also the sugar boom came quite a bit later than the period we're discussing here.
I'll probably be around tomorrow to discuss further. Interesting ideas, for sure.
The population reached a nadir in the early seventeenth century then began to grow
A long time after c.1520!
not sure the Spanish Netherlands (i.e., Belgium) have quite the same wetland reclamation experience as the Dutch ones but that's just a guess.
A guess I share. But, all the Netherlands were Spanish until c.1570, and nominally Spanish until 1648.
the roads weren't great
True, but those roads did carry the Manila galleon trade. Admittedly much higher value/weight though.
the sugar boom came quite a bit later than the period we're discussing here.
Perhaps a window of opportunity after the sugar islands were taking off but before the NorthAm colonies were established?
True, but those roads did carry the Manila galleon trade. Admittedly much higher value/weight though.
Also the other direction. The Pacific coast was (and remains) a lot more developed and densely populated than the Gulf coast.
Perhaps a window of opportunity after the sugar islands were taking off but before the NorthAm colonies were established?
A very brief one, if any. The initial NA colonies predate the introduction of sugar planting on the islands, which only really took off after the Dutch were kicked out of Brazil in 1661, and South Carolina was founded in 1670. I doubt Mexico could ever have really competed given the transportation costs.
I read somewhere (or heard on Mike Duncan's podcast?) the big reason for less importation of enslaved Africans into Mexico was that their most plantation-worthy areas were in the interior highlands, where (a) it was a much longer and harder trek from the coast, and (b) there was a substantial Indian population in the vicinity, lower than pre-conquest but still much denser than other parts of the Americas, which could be impressed into peonage. So when labor was desired, that was the cheaper option. And it's why Black Mexicans are more common in and around coastal cities.
Yes, Mexico just didn't have the same kind of labor crisis as the Antilles so there wasn't the same demand for slave imports.
I would like to interrupt the coming news a war crimes with a lighter note. On Duolingo, I have just gotten to where they taught me the word "libro de cocina".
In Africa, however, smallpox was epidemic rather than endemic
Interesting. Why? Lower population density?
And lower densities of / less close contact with cattle?
Lower density is one of the reasons usually given, yes. I'm a bit skeptical of that as a general description of precolonial Africa, but it would help explain this phenomenon. Less contact with domestic animals might be an explanation for coastal areas beyond the tsetse belt but a fair number of slaves were drawn from pastoral areas pretty far inland. Contact with animals wouldn't have any effect on human-exclusive diseases like smallpox, of course.
Better indoor ventilation, at least in winter?
Relative lack of winter and more time spent outside, maybe. I wish we had better information on the actual architecture and community layouts to ground some of these speculative ideas, but not much tends to survive long in those climates.
54.2: Have you looked into that? My impression was that architecture and layout were well-attested and excavated (leaving at least earthworks, even if upper structures were perishable), at least for larger centers. Though IIRC the specific things I'm thinking of were later, 18th-19th C.
I've looked into it a bit but I'm not up on all the latest research. It's quite possible there's more detail available than I'm aware of. This is something I'll be looking into in more detail as I go forward with my epidemics project as it seems to be more important to understanding the New World situation than I had originally realized. I'll have a blog post on that soon.
