Happy STS! If you haven't written about this already I would love to know more about these different sectors and what they entail
Thank you for the ask! <3
The Sectors are one of my favorites in the story, so I'm glad I can talk about them.
Ionera has three Sectors as I listed in the intro: Aquor, Terran and Caelus.
The Aquor Sector is the lowest one, which is the closest to the water, therefore it's naturally the most endangered one too. If a Rising comes, aquorian the first ones to suffer the consequences. They also have access only to barely eatable food that definitely has a mutagenetic effect, so people in this Sector usually wear clothes that hides every body part, including their face, so they don't display where the mutation started to change them. Only their eyes are visible usually. People here also tend to get augmentations frequently, since a little too much food or clumsier platform lifting during a Rising and the mutation gets advanced enough to make a limb useless. And useless means death here. This Sector also became the trash container of Ionera, since the landhfill is here too. Everything that's defective, demaged or too aged goes to this Sector. Aquorian also doesn't really an educated lot, since surviving eats their time up mostly, so if they somehow get a decent job at a higher Sectorn that can only be something like cleaning a lowly bufet's floor or picking up trash tech stuff and deliver to the landfill. Also, there's a lot of trashmech out there, mostly taught by themselves. It's a very hopeless, depressive and dirty place with a folk that doesn't welcome other's from higher Sectors.
The Terrana Sector however, is in a better condition. This is where the avarage life happens. There are schools, decent jobs, more eatable food in here, people don't need to constantly stay alert what's happening with the Everocean. The occaisonal wave's sounds are quieter here even. The Rising rarely gets up this high, but it can still reach the platform sometimes. Thanks to the Divum Council, Terrana's society is very divers and cohesive, welcoming the Restored back like a family and it's uncommon to have riots or any upheaval around here. Or at least, that's the picture the Council like to advertise. What's sure is that terranan are the common people, having almost as common life as we have, mostly. The members of the Deep Corps also recruited from here too. The mutation level is way lower here than at the Aquor Sector, but it's still high enough for people to have a fashion that hides most of the body. Augmentations are more higher quality here, people even can get some by public funding, like the members of the Deep Corps and their families for example. In spite of being in relatively good condition, Terrana is still a place where people can't really get higher from. If you were born to a terranan, you'll most likely stay a terranan. Even though, there's a conception that was spread across the Sector, which say if you work hard enough (meaning: taking samples and studying them, then handing the results to the professors to send them to the Caelus Sector), you can get into the highest Sector and making your family a comfortable life etc.
The Caelus Sector is directly below the top, therefore it's the highest from all. People here are kind of act like they're gods on the Olympus. They live in luxury compared to the other two Sector. The explanation were always that; scientists, engineers and everyone who keeps Ionera going needs a safe place to concentrate on their work and making people's life better. So, to not distress them, they became the elite. I would probably compare their attitude to the meth's in Altered Carbon (the Netflix series, not the book). Most high-tech labs are here, besides the research, the food-water cleaner and the restoration facilities. There are also separated platforms here, "little islands" as some of them call it which are owned by the welthiest and the members of the Divum Council. These two things usually comes together.
The fashion contains very loose, very showing clothes, people display their skin and their augmentations which wouldn't be necessary here, since no Rising can get this platform, but they still do them. Usually from rare and/or more nice material than you can find in any other Sector and they also even has decorations that matches the people's clothes in the current day or something. So more fashion ans status symbol, than function of course. Caelusian also act like they're saviors. They'll say they do augmentations as a gesture of compassion towards the lower Sectors and some other similar bull. Also, they even change their hair and eye color with some gene modification (because there's no things for hair dye anymore, so they just straight out do this instead). So, the Caelus Sector has only white haired, very blue eyed folk which makes them pretty odd and not in a good way. Aquoran calls them basically aliens. And our main boy Dane needs to change his hair and eyes to these too when he gets into the Council.
Huh it was so great to write this out, thank you! <3 I probably left out a lot, but if you're interested in anything else in them, then shoot!