Extended Data Fig. 7: Sensitivity test Part 1 and Part 2 results.
From: Sill-controlled salinity contrasts followed post-Messinian flooding of the Mediterranean
(a,b; Sensitivity test Part 1 - Testing for different initial salinity profiles) a, Initial wMed salinity profiles used for the test; surface layer (430–560 m) and residual brine layer (below 1750 m) salinities were kept unchanged at 40 and 140 PSU, respectively. Mid-layer salinity was changed, as shown in the Figure (ISP 1 to ISP 6, ISP; initial salinity profile). For the mid-layer, salinity was increased linearly from 40 PSU at 560 m, to 50 PSU (ISP 1), 60 PSU (ISP 2), 80 PSU (ISP 3), 100 PSU (ISP 4), and 120 PSU (ISP 5), at the deep brine surface (1750 m). ISP 6 is the same as used in Extended Data Fig. 6. The black dotted line is wMed hypsometry. b, Evolution of the mixing depth at 100% mixing efficiency for different starting salinity profiles in a. For ISP 1, mixing depth reaches the brine surface, but the flood energy is insufficient to erode the brine layer. Maximum mixing depth does not extend below 1500 m for any other starting salinity profile, implying that the flood energy is insufficient to reach deep wMed brines below 1750 m. The same colours for ISPs are used for mixing depth evolution lines. The black dotted line indicates the wMed level rise as Atlantic waters fill the Mediterranean. (c,d; Sensitivity test Part 2) c, Approximation of the final eMed salinity below the Sicily Sill at the end of basin refilling (Zanclean flooding), as a function of initial Mediterranean residual fluid salinity. Residual fluid salinity in wMed and eMed are considered equal. Below 140 PSU, all wMed salt will be transferred to the eMed. d, eMed evolving phase when initial residual fluid salinity is set below 140 PSU (140 PSU was used for the main text model calculations - see Methods for reasoning). Duration of salt removal is tested at initial salinities of 60, 80, 100, and 120 PSU. The dotted line represents the maximum eMed surface salinity. The purple box above the time axis represents the expected salt removal duration for salinities between 60 and 120 PSU.
