A review of 917 relative sea-level (RSL) data-points has resulted in the first quality-controlled database\ud constraining the Holocene sea-level histories of the western Mediterranean Sea (Spain, France, Italy, Slovenia,\ud Croatia, Malta and Tunisia). We reviewed and standardized the geological RSL data-points using a new multiproxy\ud methodology based on: (1) modern taxa assemblages in Mediterranean lagoons and marshes;\ud (2) beachrock characteristics (cement fabric and chemistry, sedimentary structures); and (3) the modern distribution\ud ofMediterranean fixed biological indicators. These RSL data-pointswere coupled with the large number of\ud archaeological RSL indicators available for the westernMediterranean. We assessed the spatial variability of RSL\ud histories for 22 regions and compared these with the ICE-5G (VM2) GIA model. In the western Mediterranean,\ud RSL rose continuously for the whole Holocene with a sudden slowdown at ~7.5 ka BP and a further deceleration\ud during the last ~4.0 ka BP, afterwhich time observed RSL changes are mainly related to variability in isostatic adjustment.\ud The sole exception is southern Tunisia, where data show evidence of a mid-Holocene high-stand compatible\ud with the isostatic impacts of the melting history of the remote Antarctic ice sheet.\ud Our results indicate that late-Holocene sea-level rise was significantly slower than the current one. First estimates\ud of GIA contribution indicate that, at least in the northwestern sector, it accounts at least for the 25–30% of the ongoing\ud sea-level rise recorded by Mediterranean tidal gauges. Such contribution is less constrained at lower latitudes\ud due to the lower quality of the late Holocene index points. Future applications of spatio-temporal\ud statistical techniques are required to better quantify the gradient of the isostatic contribution and to provide improved\ud context for the assessment of 20th century acceleration of Mediterranean sea-level rise

[1] We use 2.5 to 14 years long position time series from >800 continuous Global Positioning System (GPS) stations to study vertical deformation rates in the Euro-Mediterranean region. We estimate and remove common mode errors in position time series using a principal component analysis, obtaining a significant gain in the signal-to-noise ratio of the displacements data. Following the results of a maximum likelihood estimation analysis, which gives a mean spectral index~À0.7, we adopt a power law + white noise stochastic model in estimating the final vertical rates and find 95% of the velocities within ±2 mm/yr, with uncertainties from filtered time series~40% smaller than from the unfiltered ones. We highlight the presence of statistically significant velocity gradients where the stations density is higher. We find undulations of the vertical velocity field at different spatial scales both in tectonically active regions, like eastern Alps, Apennines, and eastern Mediterranean, and in regions characterized by a low or negligible tectonic activity, like central Iberia and western Alps. A correlation between smooth vertical velocities and topographic features is apparent in many sectors of the study area. Glacial isostatic adjustment and weathering processes do not completely explain the measured rates, and a combination of active tectonics and deep-seated geodynamic processes must be invoked. Excluding areas where localized processes are likely, or where subduction processes may be active, mantle dynamics is the most likely process, but regional mantle modeling is required for a better understanding.

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ICESat has provided surface elevation measurements of the ice sheets since the launch in January 2003, resulting in a unique dataset for monitoring the changes of the cryosphere. Here, we present a novel method for determining the mass balance of the Greenland ice sheet, derived from ICESat altimetry data. <br><br> Three different methods for deriving elevation changes from the ICESat altimetry dataset are used. This multi-method approach provides a method to assess the complexity of deriving elevation changes from this dataset. <br><br> The altimetry alone can not provide an estimate of the mass balance of the Greenland ice sheet. Firn dynamics and surface densities are important factors that contribute to the mass change derived from remote-sensing altimetry. The volume change derived from ICESat data is corrected for changes in firn compaction over the observation period, vertical bedrock movement and an intercampaign elevation bias in the ICESat data. Subsequently, the corrected volume change is converted into mass change by the application of a simple surface density model, in which some of the ice dynamics are accounted for. The firn compaction and density models are driven by the HIRHAM5 regional climate model, forced by the ERA-Interim re-analysis product, at the lateral boundaries. <br><br> We find annual mass loss estimates of the Greenland ice sheet in the range of 191 ± 23 Gt yr⁻¹ to 240 ± 28 Gt yr⁻¹ for the period October 2003 to March 2008. These results are in good agreement with several other studies of the Greenland ice sheet mass balance, based on different remote-sensing techniques

We quantify the effects of post-seismic deformation on the radial and horizontal components of the displacement, in the near- and far-field of strike- and dip-slip point dislocations; these sources are embedded in the elastic top layer of a spherical, self-gravitating, stratified viscoelastic earth. Within the scheme of the normal mode technique, we derive the explicit analytical expression of the fundamental matrix for the toroidal component of the field equations; this component is propagated, together with its spheroidal counterpart, from the core-mantle boundary to the earth's surface. Viscosity stratification at 670km depth influences the radial and horizontal deformation accompanying viscoelastic relaxation in the mantle over time-scales of 103-104 yr, both in the near-field, ranging from 100 to 500 km and in the far-field, from 103 to 5 X 103 km. If the upper mantle is differentiated into a low-viscosity zone beneath the lithosphere and a normal upper mantle, faster relaxation is obtained. For an asthenospheric viscosity of 1020 Pa s we obtain, for a strike-slip dislocation and a seismic moment of 1022 N m characteristic of an average large earthquake, horizontal rates of 1-4 mm yr-1 in the near-field and 0.05-0.4 mm yr-1 in the far-field; these values are maintained over time-scales of 10-103 yr. Larger rates, with shorter duration, are obtained if the viscosity is reduced in the low-viscosity channel. As expected, strike-slip dislocations are the most effective in driving horizontal deformation in the far-field in comparison with dip-slip ones. It is noteworthy that horizontal velocities are maintained longer in the far-field in comparison with radial ones, which is not surprising since momentum is propagated in far regions essentially in the horizontal direction; radial deformation is generally lower in the far-field. VLBI techniques, with a precision of a few parts per billion over distances of 103 km, can detect global post-seismic deformation induced by large earthquakes. Our results affect the interpretation of the transfer of stress and seismic activity among different plate boundaries

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We use 1277 tide gauge records since 1807 to provide an improved global sea level reconstruction and analyse the evolution of sea level trend and acceleration. In particular we use new data from the polar regions and remote islands to improve data coverage and extend the reconstruction to 2009. There is a good agreement between the rate of sea level rise (3.2 ± 0.4 mm·yr ). Choice of GIA correction is critical in the trends for the local and regional sea levels, introducing up to 8 mm·yr