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Table 1.
Coordinates of the observatories used in this study. Corrected geomagnetic coordinates (CGM) are given for the years 2000 and 1900a. The last column gives the linearly extrapolated value for 1850. For Nurmijärvi, Tartu and Dourbes, the CGM coordinates in 1850 and 1900 are irrelevant.
| Code | Full name | lat | lon | latm2000 | latm1900 | latm1850 |
|---|---|---|---|---|---|---|
| STP | St. Petersburg | 59.93 | 30.30 | 56.16 | 54.73 | 54.01 |
| EKA | Ekaterinburg | 56.82 | 60.58 | 52.72 | 50.39 | 49.23 |
| BAR | Barnaul | 53.33 | 83.95 | 48.97 | 47.22 | 46.35 |
| NER | Nertchinsk | 51.32 | 119.60 | 45.87 | 45.30 | 45.02 |
| NUR | Nurmijärvi | 60.50 | 24.65 | 56.90 | – | – |
| TAR | Tartu | 58.26 | 26.46 | 54.48 | – | – |
| DOU | Dourbes | 50.1 | 4.6 | 45.88 | – | – |
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