We examined tide gauge records at stations in and around the Kui peninsula to find if a precursory crustal deformation occurred before the 1946 Nankai earthquake. First, we removed effects of atmospheric pressure and astronomical tide on the records. Then, we tried to get rid of the effects of the oceanic current by taking the difference of the records betweentwo stations. After these corrections we found that sea level at Uragami where is located on the southeastern coast of the Kui peninsula had risen about 10 cm just before the Nankai earthquake. The sea level change, if we consider that to represent real subsidence of land near Uragami, could be explained by supposing that a slow fault slip corresponding to moment magnitude 6.9 occurred on the plate boundary in the offing of southeast of the Kui peninsula near the hypocenter of the Nankai earthquake.

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The accuracy reached in the past few years by Satellite Laser Ranging (SLR) allows for measuring even tiny features of the Earth's gravitational field predicted by Einstein's General Relativity by means of artificial satellites. The gravitomagnetic dragging of the orbit of a test body is currently under measurement by analyzing a suitable combination of the orbital residuals of LAGEOS and LAGEOS II. The lower bound of the error in this experiment amount to 12.92%. It is due to the mismodeling in the even zonal harmonics of the geopotential which are the most important sources of systematic error. A similar approach could be used in order to measure the relativistic gravitoelectric pericenter shift in the field of the Earth with a lower bound of the systematic relative error of 6.59×10^-3 due to the even zonal harmonics as well.The inclusion of the ranging data to the Japanese passive geodetic satellite Ajisai would improve such limits to 10.78% and 8.1×10-4 respectively and would allow to improve the accuracy in the determination of the PPN parameters β and γ.

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Baseline observations, byproducts of various VLBI measurement sessions (experiments) from different VLBI networks, are routinely used to monitor changes in the baseline lengths as a result of plate motions. In this study, we investigate whether the baselines from different VLBI networks are significantly different from each other, which may be due to the changingexperimental conditions of sessions or differing network geometries . We also assess their potential impact on the baseline rates. An analysis of variance model (ANOVA) is constructed for this purpose. Out of seventeen baselines examined five baselines measurements are found to be incompatible with each other at 0.001 p-level. However out of five baseline rates, only one baseline rate was significantly affected by the inhomogeneities induced by different networks.

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