“West Antarctica is so large that it pulls the global ocean toward it, which slopes upward toward the ice sheet and the Antarctic continent in general. But if West Antarctica were to lose a substantial part of its ice, then the gravitational pull would relax, and sea level would actually decrease near the ice sheet even as it spreads and increases across the global ocean.
But not evenly. Instead, areas farther from West Antarctica would get more sea level rise, and North America and the United States might get more than any other inhabited place on Earth.”
http://www.washingtonpost.com/news/energy-environment/wp/2015/01/22/the-u-s- has-contributed-more-to-global-warming-than-any-other-country-heres-how-the- earth-will-get-its-revenge/

Yes, I needed to keep you in the loop, as it were, as it’s the only respectable thing to do.

(4) The “grey zone” at least for the CONUS would mostly affect the areas of relatively low relief which have large unconsolidated sedimentary deposits, primarily the east and gulf coasts (and similarly globally).

I’m currently using hypsometry data (one minute resolution) from NOAA:

http://www.ngdc.noaa.gov/mgg/global/etopo1_surface_histogram.html
http://www.ngdc.noaa.gov/mgg/global/etopo1_elevation_histogram.xls

The Excel file is in aggregate horizontal depth bins (and one needs to perform a vertical integral instead of a horizontal integral to see the volume versus ocean depth relationship).

Anyways, the hypsometry above current RSL appears to be significantly flatter than that below RSL (at least visually from the NOAA graphic).

One can make a 1st order SWAG using the current hypsometry raised so many meters (worth a try).

(1) & (2) Yes, the dynamic geoid (solid earth) work I mentioned above suggests that CONUS could see ~1.4 the SLE for WAIS and GrIS (five meters of SLE). Tides will change as well as steric effects.

(3) Long term GIA (pitch & heave DOF’s) would occur in those areas that lose their ice sheets.

So yes, the subject is rather complex and perhaps beyond our current understanding to some degree.

However, these calculations are meant to be ‘dumbass’ simple, in terms of global sea level equivalent, and as such the 1st metric will always be a rather simple ‘what melts here will end up here’ in a uniform global sense.

That is all.

The difference between the two estimates (and that difference is too large to be OK, we need to get the numbers right) does not affect the outcome of my map, given the very coarse divisions used in the original USGS map that I based it on. In fact, 64 meters is what I used as the cutoff because it was closest to the 80 m estimate, to provide a very conservative estimate of a fully inundated coast line. The upper elevation, which defines the upper end of the “gray zone” (shaded in gray!) is much higher than the 80 meter USGS estimate (114 meters). The purpose of the grey zone is to define the region in which a more careful and local look would be required to actually place the strand line if ALL of the ice melted. This needs to be a large area because of several factors. First, sea level does not rise uniformly. Second, gravitational effects would increase sea level beyond a simple estimate of water volume. Third, there might be in some places, isostatic effects that increase effective sea level rise. Fourth, and probably most important, transgression will eventually cut the strand line horizontally horizontally a great distance, such as on glacial moraines (i.e., Long Island) where eventually the non-bedrock sediment will be eroded away no matter what the elevation.

But thank you for writing the letter to the USGS. It would be nice to have numbers in which we have more confidence.

I have just emailed the appropriate list of people at the USGS, IPCC lead authors (USA) and the corresponding authors of the two peer reviewed papers as cited above.

Hopefully, this matter will be addressed by the appropriate individuals/bodies in regards to this matter.

Thank you very much.

Very Respectfully,
Everett F Sargent

(But, as I said, the coarseness with which the map is made is so great, combined with the uncertainty as to where the strand line would erode to, makes it almost moot unless one does a really detailed geophysical study.)

BENGHAZI1!!!1!