1. The IfE absolute gravimetry campaigns 2003, 2004, 2005: an epilogue Olga Gitlein, Ludger Timmen

2. epochIfEtotal different FG5’s institutions 200316228BKG, FGI, IfE 200416244FGI, IfE, UMB 200513304FGI, IfE, UMB 2003- 2005 2534 Absolute gravity station distribution

3. StationGPS200320042005total Ålesundx1 Andøyax1 Ås1 Bodø1 Hønefoss AC1 Tromsøx1 Trondheimx1 Trysil ACx1 Cophg./Budd.x1 Cophg./Vestv.3 Bornholmx1 Helsingør2 StationGPS200320042005total Arjeplogx3 Boråsx1 Kirunax2 Kramfors3 Mårtsbox2 Onsalax3 Östersundx3 Skellefteåx3 Visby AAx2 Metsähovix 5 Sodankyläx1 Vaasa AA1 Vaasa ABx3 ∑ 16 1347 Station occupations by IfE in 2003 – 2005 25 different stations

4. differences due to: Uplift signal measurement uncertainty Local and regional groundwater residual air mass effect Soil moisture Wind driven sea and ocean water flow [µGal] MINMAXMEANRMS -4.21.8-0.8±1.9 Comparison of 2004 and 2005 results Absolute gravity results in 2005 are less than in 2004 at nearly all 13 stations. Absolute gravity difference 2005 – 2004

5. gravity difference at ~120 cm sensor height from absolute and relative gravity measurements between two pillars at Metsähovi, Onsala and Bad Homburg Instrumental precision Metsähovi AB-AC Onsala AS-AN Bad Homburg BA-AA dg(rel) ±0.5 µGal 1.97.734.9 Difference dg(abs) – dg(rel) [µGal] 1.91.4-2.6 -1.61.1 0.1 2.7 1.7 1.9 0.2 Onsala ±1…±2 µGal  several setups to minimize the instumental uncertainties (Floor-recoil, azimuth (Coriolis/attrition), setup,…)

6. Summary of IfE campaigns 2003 – 2005 25 different stations occupied by IfE accuracy for one station determination ±2…±4 µGal several FG5 setups per station relative gravimetry:vertical gradients (<±1 µGal) eccentres (national net points) monitoring of lokal water level (groundwater, lakes) monitoring of height changes of absolute gravity point  levelling to height benchmarks at nearly all stations continuous GPS available connection to tide gauges