Gravity recovery and climate experiment (GRACE)-derived temporal gravity variations can be resolved within the µgal (10 −8 m/s 2 ) range, if we restrict the spatial resolution to a half-wavelength of about 1,500 km and the temporal resolution to 1 month. For independent validations, a comparison with ground gravity measurements is of fundamental interest. For this purpose, data from selected superconducting gravimeter (SG) stations forming the Global Geodynamics Project (GGP) network are used. For comparison, GRACE and SG data sets are reduced for the same known gravity effects due to Earth and ocean tides, pole tide and atmosphere. In contrast to GRACE, the SG also measures gravity changes due to load-induced height variations, whereas the satellite-derived models do not contain this effect. For a solid spherical harmonic decomposition of the gravity field, this load effect can be modelled using degreedependent load Love numbers, and this effect is added to the P. Schwintzer has deceased. satellite-derived models. After reduction of the known gravity effects from both data sets, the remaining part can mainly be assumed to represent mass changes in terrestrial water storage. Therefore, gravity variations derived from global hydrological models are applied to verify the SG and GRACE results. Conversely, the hydrology models can be checked by gravity variations determined from GRACE and SG observations. Such a comparison shows quite a good agreement between gravity variation derived from SG, GRACE and hydrology models, which lie within their estimated error limits for most of the studied SG locations. It is shown that the SG gravity variations (point measurements) are representative for a large area within the µgal accuracy, if local gravity effects are removed. The individual discrepancies between SG, GRACE and hydrology models may give hints for further investigations of each data series.

S U M M A R YA detection of the Slichter modes is attempted using a new method that focuses on the use of the spectra of individual superconducting gravimeter (SG) records to test if the latitudinal and longitudinal dependence of amplitudes and phases of the Slichter modes are satisfied in a statistical point of view. The new method allows considerations of lower peaks in the spectra as possible candidates of the Slichter modes. As the new method searches for the three Slichter modes individually, it does not rely on the theory of splitting which remains controversial, and is still valid even if not all of the three Slichter modes are excited to the observable level. A loose splitting rule is used to check if a set of candidates of the prograde, axial and retrograde modes may constitute the whole Slichter modes. The attempted detection is made using three sets of SG records selected from the Global Geodynamics Project (GGP) network based on criteria including data spans, geological locations, and the quality of the gravity time-series. The selected three data sets are the simultaneous records of five SGs located in Canberra, Matsushiro, Strasbourg, Sutherland and Vienna. The data spans are 30, 17 and 12 months, with the later two data sets after the 2001 Peruvian Earthquake of magnitude 8.4 that might have excited the Slichter modes to larger amplitudes. Our results suggest two possible scenarios that are still inconclusive. The first is a candidate of the prograde mode with a frequency around 4.485 cycle per day (cpd) that is present in all three data sets. The second is a combination of a prograde and an axial modes with frequencies around 7.098 and 7.546 cpd that are present in the two data sets after the Peruvian Earthquake.

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