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We report GPS measurements of continuous observations from the multiparametric geophysical observatory (MPGO) at Ghuttu, Garhwal Lesser Himalaya. Other than the evidence of secular motion depicting strain accumulation due to locking of the underneath seismically active detachment, measurements at Ghuttu show annual variation of ±4 mm on horizontal component. Such variations are more prominent in the north coordinate and do not directly correlate with the meteorological parameters such as variations in rainfall, water table, and atmospheric pressure measured at the MPGO observatory. These variations are also not the artefact of data processing and network. They correlate with the water load storage in the Ganga plains, with minimum in displacement coinciding with the maximum storage of water in Ganga plains immediately after the monsoon and vice versa. Such variations also appear to cause annual variation in the low-magnitude earthquake frequency in the Himalayan region, being relatively more in the winter period.

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Simultaneous observations of gravity measurements and vertical crustal deformation are carried out at the Multi-Parametric Geophysical Observatory (MPGO), Ghuttu (Location 30.53 o N, 78.74 o E) located in Northwestern part of Himalaya in India. The temporal variation of gravity measurements are monitored by a superconducting gravimeter while the crustal deformations are observed using a dual frequency GPS antenna and receiver system. The simultaneous data collected by both instruments during a period of ~3 years from 2007 to 2010 is evaluated. Both data sets show apparent seasonal/annual changes with a clear phase difference of few months causing negative correlation between the two time series. Loading effects on the Earth's uppermost crust due to the hydrological cycle, as measured from local water table record, are advocated as the explanation of the observed seasonal variation.