Isostatic rebound following the Alpine deglaciation: impact on the sea level variations and vertical movements in the Mediterranean region

Geophysical Journal International (Impact Factor: 2.72). 06/2005; 162(1):137 - 147. DOI: 10.1111/j.1365-246X.2005.02653.x

ABSTRACT The present-day sea level variations and geodetically observed ground deformations in the Mediterranean area are normally ascribed to the combined effect of tectonic or human-driven subsidence and postglacial uplift as a result of the melting of the major Pleistocene ice sheets. However, another potential cause of deformation, only marginally considered to date, is the melting of the glacier that covered the Alps during the last glacial maximum (LGM). The aim of this paper is to predict the long-term sea level variations induced by the melting of both the late-Pleistocene and Alpine ice sheets and compare our results with the relative sea level (RSL) observations available in the Mediterranean region. This task is accomplished solving the sea level equation (SLE) for a spherically symmetric viscoelastic Earth. Our analysis shows that the melting of the Alpine glacier has marginally affected the Holocene sea level variations in the near-field sites in southern France (Marseilles and Roussillon) and the central Tyrrhenian sea (Civitavecchia), and that the RSL predictions are significantly sensitive to the chronology of the remote ice aggregates. The computations, which are performed using a specific mantle viscosity profile consistent with global observations of RSL rise, show that the uplift rate driven by the Alpine isostatic readjustment may account for up to of the rates observed at GPS stations in the western portion of the chain. Our results suggest that a thorough modelization of both near- and far-field ice sheets is necessary to gain a better insight into the present-day deformations and sea level variations in the Mediterranean region.

  • [Show abstract] [Hide abstract]
    ABSTRACT: The 9 longest tide-gauge records in the Mediterranean Sea are compared with the output of a barotropic model forced by atmospheric pressure and wind. Between 1958 and 2001 the tide-gauges indicate sea level trends of -0.4 to 0.7 mm/yr. During the same period the model shows sea level reduction of -0.4 to -0.7 mm/yr linked with the North Atlantic Oscillation (NAO). After the removal of the meteorological influence from the sea level records the resulting trends are ~0.3 +/- 0.4 mm/yr at the western Mediterranean and ~1.3 +/- 0.4 mm/yr at the eastern Mediterranean. The eastern basin is strongly affected by rapid sea level rise in the period 1993-2001 with rates of 5-10 mm/yr which are probably related to the Eastern Mediterranean Transient (EMT).
    Geophysical Research Letters 10/2005; 32(20):20602-. DOI:10.1029/2005GL023867 · 4.46 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Insights into the present vertical kinematic pattern in Central and Northern Italy are gained by the analysis of GPS data acquired by a network of 262 permanent stations, working over various time intervals since 2001. Uplift is observed in the Alps (up to 5 mm/yr) and Apennines (1–2 mm/yr), whereas subsidence is recognized in the southern Venetian Plain (2–4 mm/yr) and the eastern Po Valley, where the highest rates are observed (up to 9 mm/yr between Reggio Emilia and Rimini). On the other hand, the western part of the Po Valley presents very low vertical rates. The boundary between subsiding and not subsiding Po Valley nearly corresponds to the Giudicarie tectonic discontinuity. It is argued that the different kinematic patterns of the eastern and western Padanian sectors may also be related to the underthrusting of the eastern domain beneath the western one. Some considerations are then reported on how the various causes of vertical movements (tectonic and sedimentological processes) may contribute to the observed kinematics.
    Journal of Geodynamics 11/2013; 71:74–85. DOI:10.1016/j.jog.2013.07.004 · 2.62 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: In spite of very favourable coastal features, late Pleistocene-Holocene relative sea-level changes along the eastern Adriatic coast are still not completely resolved mostly due to the intensive and complicated regional and local neotectonics. We gathered current knowledge that generally presents the north Adriatic area as subsiding one, and proposed a reconstruction in new light of possible very slow (local) uplift (average rate of 0.1–0.25 mm/a for last 80 ka) which is supported by well-dated submerged speleothems and tectonic reconstruction. In addition, such a scenario supports also the formation of tidal notches that are common in the north Adriatic region, but not yet entirely understood. However, according to the latest Mediterranean data on sea level during the marine isotope stage (MIS) 5.1 being at + 1 m 80 ka ago, we do not dismiss the possibility of subsidence which would have been 0.18–0.23 mm/a on average for the last 80 ka, but notch formation under such condition would not have been realistic. Apparently, the position of the north-eastern Adriatic coast on a convergence area requires extensive palaeoenvironmental studies, including structural, lithostratigraphical, palaeontological, archaeological and radiometric data and application of isostatic modelling.
    Geomorphology 09/2014; 220:93–103. DOI:10.1016/j.geomorph.2014.06.001 · 2.58 Impact Factor


Available from
Jun 1, 2014