Decoding Last Interglacial sea-level variations in the Western Mediterranean using speleothem encrustations from coastal caves in Mallorca and Sardinia: A field data - model comparison
U-Th ages of phreatic overgrowths on speleothems in coastal caves of the Western Mediterranean record
high sea level positions during marine isotope stage (MIS) 5e of the last interglacial.While relative sea level
(RSL) on the southeastern coast of Mallorca stood w2.6 m above present sea level (apsl) during MIS 5e, it
stood w4.3 m apsl at this time in northwestern Sardinia. The difference between the two sites during MIS
5e and the deviation from the eustatic sea level trend during the Holocene was investigated using the
numerical code SELEN. The offset between the eustatic curve and those pertaining to the two sites principally
reflect the vertical deformations and geoidal variations in response to meltwater loading. As Sardinia
is closer to the center of the Mediterranean basin, the hydro-isostatic component of RSL is enhanced
here compared to Mallorca, which results in a modeled offset ofw60 cm between the two sites. This result
is qualitatively useful as it provides a partial reconciliation for the site differences. However, the need for
refinement in the model is also recognized, as it does not match the observation based on UeTh dating of
speleothem overgrowths in Mallorca that sea level there has remained stable for the past 2800 years.
Overall, the results of the study first suggest that both sites largely track the eustatic sea level curve, and
second suggest that glacial isostatic adjustment is a viable mechanism to reconcile some, if not most, of the
relatively small elevation difference of MIS 5e sea level observed at Mallorca and Sardinia, although minor
tectonic adjustments cannot be ruled out in explaining some low-amplitude local variation