| Title | Constraints on secular geocenter velocity from absolute gravity observations in central North America: Implications for global melting rates |
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| Author | Lambert, A ;
Huang, J; Courtier, N; Pavlic, G |
| Source | Journal of Geophysical Research, Solid Earth vol. 128, issue 2, 2022 p. 1-21, https://doi.org/10.1029/2022JB024991 |
| Image |  |
| Year | 2022 |
| Alt Series | Natural Resources Canada, Contribution Series 20200412 |
| Publisher | John Wiley & Sons, Inc. |
| Document | serial |
| Lang. | English |
| Media | paper |
| File format | pdf |
| Province | Canada; Canada; British Columbia; Alberta; Saskatchewan; Manitoba; Ontario; Quebec; New Brunswick; Nova Scotia; Prince Edward Island; Newfoundland and Labrador; Northwest Territories; Yukon;
Nunavut |
| NTS | 1; 2; 3; 10; 11; 12; 13; 14; 15; 16; 20; 21; 22; 23; 24; 25; 26; 27; 28; 29; 30; 31; 32; 33; 34; 35; 36; 37; 38; 39; 40; 41; 42; 43; 44; 45; 46; 47; 48; 49; 52; 53; 54; 55; 56; 57; 58; 59; 62; 63; 64; 65;
66; 67; 68; 69; 72; 73; 74; 75; 76; 77; 78; 79; 82; 83; 84; 85; 86; 87; 88; 89; 92; 93; 94; 95; 96; 97; 98; 99; 102; 103; 104; 105; 106; 107; 114O; 114P; 115; 116; 117; 120; 340; 560 |
| Area | United States of America |
| Lat/Long WENS | -120.0000 -70.0000 60.0000 40.0000 |
| Subjects | geophysics; Nature and Environment; Science and Technology; velocity surveys; climate effects; climate; isostasy; ice; ice sheets; glaciers; Climate change |
| Illustrations | location maps; graphs; plots; flow charts; tables |
| Program | Groundwater Geoscience National Aquifer Evaluation & Accounting |
| Released | 2022 12 09 |
| Abstract | Long series of absolute gravity observations at multiple sites provide a direct method of measuring the velocity of the geocenter caused by surface mass transport related to climate change. Annual
absolute gravity observations and available GPS vertical data at eight sites in central North America from 1995 to 2010 are used to solve for geocenter velocity while correcting for glacial isostatic adjustment. The precision of the secular gravity
trends and GPS heights at our sites, used to estimate geocenter motion, was improved by correcting for local and global water storage attraction and loading. Corrections for the loading and attraction effects of regional ice-mass loss, the atmosphere
and non-tidal ocean were found to be minimal. Our results provide a direct measurement of the change in geocenter velocity over the time-interval 2002-2010 compared to the time-interval 1995-2003 of 0.68 ± 0.28 mm/yr away from North America. This
suggests similar velocities in the negative Z (0°N) and positive Y (90°E) directions to those found by other studies. |
| Summary | (Plain Language Summary, not published)
Absolute gravity and GPS height observations collected by NRCan between 1995 and 2010 in central North America have been re-analyzed to reveal a change
in the velocity of the centre of mass of the Earth around the year 2002. This change in velocity is consistent with an acceleration in the flow of meltwater into the oceans from the major ice caps and mountain glaciers. The analysis involved
correcting the data for postglacial rebound, gravitational attraction and surface loading by time-varying water storage and the removal of an inter-annual signal common to all measurement sites. Our independent estimate of centre of mass velocity
change is slightly higher than other estimates in the literature. |
| GEOSCAN ID | 327229 |
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