Table 3 Amplitudes and signs of secular acceleration changes at the four observatories as determined from changes of slope of the piecewise linear fits (Figs. 6, 7, 8 and 9)
Interval | HER | HBK | KMH | TSU |
|---|---|---|---|---|
Declination (min/year2) | ||||
2007–2008 | −3.2 | −2.7 | No data | −4.1 |
2008–2009 | – | −2.1 | 3.5 | No data |
2009–2010 | – | – | −2.5 | No data |
2010–2011 | 1.7 | 2.3 | – | No data |
2011–2012 | – | – | 4.3 | – |
2012–2013 | −2.6 | – | −8.2 | – |
2013–2014 | Insufficient data | – | No data | −5.1 |
Horizontal intensity (nT/year2) | ||||
2007–2008 | 21.9 | 24.9 | No data | 19.1 |
2008–2009 | – | – | – | No data |
2009–2010 | – | −19.5 | −14.2 | No data |
2010–2011 | −17.9 | – | – | No data |
2011–2012 | – | – | 20.2 | – |
2012–2013 | 16.1 | 7.7 | – | −46.7 |
2013–2014 | – | – | No data | 68.5 |
Vertical intensity (nT/year2) | ||||
2007–2008 | 19.7 | 16.1 | No data | 26.9 |
2008–2009 | – | −18.0 | – | No data |
2009–2010 | – | – | −18.6 | No data |
2010–2011 | −15.9 | – | – | No data |
2011–2012 | – | – | – | – |
2012–2013 | 10.7 | 6.2 | – | – |
2013–2014 | – | – | No data | 14.1 |