Worked example
Worked example
Dare County, North Carolina · the Outer Banks
857 square kilometers of dry land on the Outer Banks, every one of them measured. On the high scenario at 2055, 436 tiles are gone — and 124 become new waterfront. Across every scenario and decade we model, at most 113 tiles — the deep mainland interior — sit beyond the water's reach; on the high scenario at 2055, 9 do. The water decides what happens here. The Arcanium Index™ decides whether it matters.
This page is a snapshot, baked 2026-09-18. It draws from the same model run that produces a member's own analyses — nothing here is illustrative, and nothing here is modelled twice.
| Fate | Tiles | Share of land | Median Index | Of the top 86 |
|---|
Every tile that is dry today is reclassified — or not — for each scenario and each decade: forecast chronic inundation in red, the hypothesized new waterfront behind it, the transition zone where the shore moves materially closer without arriving, and the ground that holds.
Step the toggles and watch the red band advance. Tiles that are open water already are not drawn at all: water today is not a forecast.
Knowing a kilometer floods is half a decision. The other half is what that kilometer was worth — and the Index answers it on one absolute scale, so a 35.3 here means the same thing as a 35.3 anywhere else on Earth.
Switch the view to the Index and the same footprint is scored rather than classified. The table above holds the two together, and it moves every time you change a scenario.
The stair-step edge is the honest statement of resolution. The model works at one kilometer — about 250 acres a tile. A smooth coastline would claim parcel-level precision the model does not hold, and a claim you cannot defend at closing is worth less than no claim at all.
Scenario and decade are on screen at all times, because "at risk" without them is not a statement anyone can act on.
Mean Arcanium Index™ 36.2 · standard deviation 5.9 · 95% interval 35.8–36.6.
We are 95% confident that the Arcanium Index™ for this land analysis is between 35.8 and 36.6.
Every scored tile, binned, under the normal curve fitted to this ground’s mean and standard deviation. Ticks mark the mean and one and two standard deviations either side; the green line is the 95% interval, drawn to scale — it is narrow because it is the interval for the Index of this ground as a whole, not the range a single tile falls in. Where the bars depart from the curve, the ground is less normal than the interval assumes.
Nothing here is a parcel-level opinion, a valuation, or investment advice. It is a measurement of ground, at one kilometer, on a scale that holds still.
This is one county, 5 scenarios, 3 decades. The published map covers every region we have scored, ranked site by site, with the same sea-level model over all of it — and anywhere we have not published can be commissioned.
See plans and pricing →© 2026 Quantum Ridge Systems, Inc. All rights reserved. Arcanium™ and the Arcanium Index™ are trademarks of Quantum Ridge Systems, Inc.