How Prototype 2 works
21 regions of US waters, from the Gulf of Maine to American Samoa, and one stretch of the Mid-Atlantic Ridge, all with one method. For any place: what public records say is known, how and when it was measured, whether a camera has seen it, and what is missing.
Getting around
- Go somewhere. Select a region (its box, its name or the list) and the map goes there. Pinch or scroll to zoom; drag to move.
- See a place. Select a hexagon for what is known there. The layers at the top colour the map by depth, surveys, detail or what has been seen.
- Come back. The globe shows the world, "Reset view" returns to the region, and the share button sends this exact view.
- More. "About this region", under the example places, counts each gap and shows where it is.
The layers
- Measured depth
- How each hexagon's depth is known: measured, interpolated, predicted or unknown.
- Survey history
- The latest survey on record. Older is not less accurate.
- Mapping detail
- How much of the hexagon has ≈100 m mapping (GMRT); elsewhere ≈460 m (GEBCO).
- Seen
- Where a camera has looked, in the dive records included.
The key's switches
- Region outlines
- Each region's box. Names still open a region with outlines off.
- Example places
- Two to six places per region, picked to show what it holds; each note is written from the data.
- Vent fields
- Hot springs on the seafloor, where life runs on chemistry instead of sunlight (InterRidge).
- Dives (seen)
- Where each dive in the records read so far began.
- Depth maps disagree
- GEBCO and GMRT give different depths and nothing in the data explains it yet. From an exploratory scan: a reason to look again, not a finding.
- Satellite-only rises
- Rises only the satellite prediction shows: possible seamounts no ship has measured, or artefacts. Same scan, unverified.
Words used here
- Hexagon
- One cell of the map's grid, about 36 km²; zoom in for finer cells of about 0.7 km².
- Measured
- Depth from a direct measurement, such as multibeam or single-beam sonar (GEBCO type codes 10–17).
- Interpolated
- Depth estimated between measurements (codes 41–44).
- Predicted
- Depth predicted from satellite gravity, not measured (codes 40 and 45).
- Seen
- A camera has looked, on a dive by a remotely operated vehicle, in the dive records read so far (NOAA's Okeanos Explorer and USGS). It sees a strip a few metres wide, so a hexagon is seen in part, never whole. Measured is not the same as seen.
- Survey record
- A survey whose outline or ship track reaches the hexagon. No record does not mean no survey.
- Gap
- Something the data cannot tell you here, in one of eight fixed sentences.
- Possible next observation
- One that could address a named gap. Unranked and not validated.
- What the numbers count
- A share of depth (measured, interpolated, predicted) is the share of the hexagon's GEBCO seafloor grid cells (15 arc-seconds) with that type code; region figures average the hexagons. Seen counts hexagons a dive track crosses. Survey counts are distinct surveys; outline coverage is the area of their union, so overlaps count once. Dates are as each catalogue gives them, some by year only.
Every method, test and limit, on one page: Methods and limitations.
One test, written down first
Datasets and licences
Since Prototype 1
Prototype 1 showed one region and what was measured there; it stays as it was. Prototype 2 adds US waters region by region, what has been seen, older ship tracks and NOAA's charting surveys, and tests how much the records read change the answer. Every version is in the prototype history.
