Brilliant Easter Egg: Atlanta

Through a bizarre twist of geography, despite lying less than 400km (250mi) from tidewater, Atlanta is one of only a handful of major cities in the Eastern United States that could survive a catastrophic sea level rise with waters requiring a protracted period to recede. Atlanta and Pittsburgh - for random, yet similar reasons - are a pair of anomalous safe havens in the hellish hypothetical sweepstakes of global seawater drowning. Most safe U.S cities are set much, much further west.

How do we know Atlanta could survive?

To determine Atlanta's fate, we have to start by calculating the height of the super tsunami. We hear 300 feet mentioned twice on the show, but a key visual tells us that's not quite correct.

The opening of Episode 5 fades in with a shot of the pyramidion from top of the Washington Monument peeking up over the ocean tides - the pyramidion being the four-sided pyramid at the white obelisk's phallic tip. The Washington Monument is raised on a patch of dirt a scant 7 metres above sea level with its stones stacked to a height of 555 feet. The pyramidion, however, is a full 55 feet high on its own, putting the land beneath the waterline at a net depth of almost exactly 500 feet, or ~153 metres. Add another 7 metres accounting for that elevation at the spot where the monument stands, et voilà!, a total increase in sea level of 160 metres (see the accompanying maps).

We know its impossible to have a sustained sea level rise to those heights. Even the melting of all land-based ice on Earth would only produce a 70 metre rise; however, that first horrifying establishing shot in Episode shows plastic garbage has floated to the surface of the ocean over DC and begun to gather in clumps. We can assume based on this that water has remained at an ~160 metre level at least long enough for everyone in the capital to expire.

How fares Atlanta?

Nestled in the southern foothills of the Appalachian Mountains, Atlanta is sitting pretty compared to DC. The city reaches at a max elevation of 320 metres (1,050 feet) above sea level with a minimum elevation is 225 metres (738 feet). But even those number understates the level of protection enjoyed by The Big Peach.

Most cities in the Eastern U.S. would be entirely destroyed in an event like this. New York, Houston, Washington, D.C., Philadelphia, Miami and Boston are on-or-near bodies of water sea level. They'd all be wiped off the map immediately. Cincinnati, Dallas and St. Louis would all suffer catastrophic flooding. But not Atlanta.

Atlanta, Chicago, Detroit and Minneapolis are the only cities with over 3 million people anywhere near the east coast, or the Gulf of Mexico, that would go unscathed in such a disaster. The eastern safe zone is north of Atlanta and west of Pittsburgh. As alluded to above, Pittsburgh - in symmetry to Atlanta - is even better protected than cities further to the west thanks to its fortuitous position on the northern edge of that same Appalachian Mountain range that protects the Capital of the New South.

In fact, the only parts of Atlanta that even stand at 225 metes (738 feet) are the low lying areas along the Chattahoochee river and the other, smaller rivers and streams that feed it. Even if the wave at impact towered 260 metres tall - 850 feet high, a full 100 metres higher than the water level shown on screen, even 400km inland - Atlanta would still remain intact.

How brilliant is it?

In selecting Atlanta as the spot to strand Xavier's wife Teri, Dan Fogelman (or members of his team) not only chose one of the most geographically plausible locations possible, but the perfect place from a storytelling point of view, too.

Atlanta is home to the headquarters of the CDC and a major centre of African American culture with a population that's 50% Black. The CDC presence and accompanying medical institutions in Atlanta explains why a doctor might have a job that takes her there so often. The large Black population is both consistent with Teri having connections to the city, but also opens up additional storytelling possibilities as Teri might have friends or family there who are stranded with her. Who knows? We meetin' the in-laws next season?

All pretty frickin' brilliant.