Measurements of Time-Variable Gravity Show Mass Loss in Antarctica
Science, 2006 · paper · Earth science
Uses GRACE satellite gravity measurements to determine mass changes of the Antarctic ice sheet during 2002–2005. Finds a significant loss of 152 ± 80 cubic kilometers of ice per year, mostly from West Antarctica, equal to 0.4 mm of sea-level rise yearly.
Checked: PDF from website.whoi.edu, fetched 4 Oct 2026. Page numbers are those of that PDF.
1 finding
Reference or label Reference 3: "C. Davis, Y. Li, J. McConnell, M. Frey, E. Hanna, Science 308, 5730 (2005)." The number after the volume appears to be the issue number, not the first page.
- p. 4 References and Notes, ref. 3
308, 5730 (2005)
- p. 4 References and Notes, entry 3
308, 5730 (2005).
- p. 4 References and Notes, ref. 3
Science 308, 5730 (2005)
Only the authors can say what is right here.
Judge's note: Rests on outside knowledge: that Science volume 308 does not run to page 5730, that 5730 is the issue number of the 24 June 2005 issue, and that the Davis et al. article starts on page 1898. The page 4 image shows the entry exactly as quoted. Internal support: the other Science entries give volume and first page ('297, 1502'; '306, 255'), and this article's own cover sheet gives 311/5768/1754, i.e. issue numbers in the 57xx range for 2005-2006 and page numbers below 2000. The correct first page cannot be verified from the files.
Second check: another model agreed
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4 minor (typos and the like; most checked by the judge only)
Wording Atmospheric trend "equivalent to about 10 km3/year" combined by root sum square with the GRACE gravity-field error ("39 ± 14 km3/year") is said to give "a new error estimate of ±16 km3/year"; the printed inputs give about 17.2.
- p. 3 Right column, first paragraph (atmospheric error)
timate of ±16 km3/year
- p. 3 Right column, first paragraph
equivalent to about 10
- p. 3 Middle column, bottom, into right column
crease of 39 ± 14 km3/year
- p. 3 Results text, right column
km3/year, and was interpreted as the uncertainty
Judge's note: Read on the page 3 image (right column): the text prints 'about 10 km3/year', RSS with the GRACE gravity-field errors (14 km3/year, from '39 ± 14'), result '±16 km3/year'. 14^2 + 10^2 = 296, square root 17.2; 16^2 = 256 would need an atmospheric term of about 7.7. The atmospheric term is only given as 'about 10' and 14 is rounded, so unrounded inputs (e.g. 13.5 and 9) could give 16; nothing elsewhere in the paper gives the exact atmospheric value. The final ±80 is unaffected (PGR ±79 dominates). Minor consistency point, either rounding or a slightly loose 'about 10'.
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Wording Fig. 2 caption: "Also shown is the linear trend that best fits the red crosses." The dashed line as drawn falls by roughly 600 km3 over about 3.3 years (about 180-190 km3/year), steeper than the stated best-fitting trend "152 ± 80 km3/year".
- p. 3 Results text, right column, final estimate
is 152 ± 80 km3/year
- p. 3 Fig. 2 caption and dashed black line
Also shown is the linear trend that best fits the red crosses.
Only the authors can say what is right here.
Judge's note: Read the dashed line off the page 3 image and the crop. Page image: line starts near +325 km3 at about 2002.3 and ends near -280 to -300 km3 at about 2005.6, giving about 185 km3/year. Crop (second half of the line): about -20 km3 at 2004 to about -305 km3 at 2005.6, about 175 km3/year. A 152 km3/year line would fall only about 500 km3 over the span. This is a graph reading with an uncertainty of perhaps 10-20 km3/year, so the gap (about 30 km3/year) is probably real but not certain. A possible explanation is that the plotted line is a plain straight-line fit while 152 comes from the simultaneous fit with annual and semiannual terms; the caption and text do not say so. Only the authors can say which line was plotted.
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Typo Note 19 thanks "S. Bettadpur, J. Cheng, J. Reis, E. Rignot, and M. Watkins for data and advice", while the satellite-laser-ranging source in reference 6 is "M. Cheng, B. Tapley"; the initial of Cheng may be wrong in the acknowledgement.
- p. 4 References and Notes, note 19
We thank S. Bettadpur, J. Cheng, J. Reis, E. Rignot, and
- p. 4 References and Notes, ref. 6
M. Cheng, B. Tapley, J. Geophys. Res. 109, B09402
Only the authors can say what is right here.
Judge's note: Rests on outside knowledge: that the Cheng who supplied the satellite-laser-ranging C20 data is the M. Cheng of reference 6 and that no separate J. Cheng was intended. The page 4 image shows 'J. Cheng' in note 19 and 'M. Cheng' in reference 6 as quoted. The other people thanked match data sources cited in the paper (Bettadpur and Watkins in ref. 8, Rignot in ref. 1), which makes a wrong initial likely, but a different person cannot be excluded from the PDF.
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Typo Note 19: "We thank S. Bettadpur, J. Cheng, J. Reis, E. Rignot, and M. Watkins"; 'Reis' is probably a misspelling of 'Ries'.
- p. 4 References and Notes, note 19
J. Reis
Only the authors can say what is right here.
Judge's note: Rests on outside knowledge: that the GRACE and satellite-laser-ranging scientist at the University of Texas Center for Space Research, a colleague of Bettadpur, Cheng and Tapley, is J. Ries. The page 4 image shows 'J. Reis' as quoted. Nothing in the PDF gives the name in another spelling, so only the authors can confirm.
Second check: none (judge only)