From the NoTricksZone
By Kenneth Richard on 6. May 2024
Human footprints embedded into rock that used to be a sand beach at the limit of the seashore’s “swash flow” and high tide lie 20 to 30 meters above the present sea level. The footprints are dated to ~90,000 years ago.
It is estimated that sea levels were globally about 6 to 9 meters higher than today during the last interglacial (~130,000 to 115,000 years ago), when CO2 supposedly peaked at 275 ppm (Sommers et al., 2022).
Image Source: Sommers et al., 2022
Evidence along the coasts of North Africa (Morocco) suggests sea levels were “20 m above the present level” about 95,000 years ago (MIS 5c).
This is consistent with a new study that reports human footprints embedded and preserved in a rocky beach “20 to 30 m above sea level” can be dated to 90.3 ±7.6 thousand years ago.
The water limit, or shoreline, very likely reached this elevation at that time, as the requisite conditions for “salt-crusting,” the preservation of footprints, involve a location at “the landward limits of the spring high tidal zone” and at the “limits of swash flow”.
Image Source: Sedrati et al., 2024
Interestingly, this same Moroccan region’s shoreline has, in recent decades, been stable to advancing seaward at a rate of +0.89 m per year (Amara Zenati et al., 2024). This is inconsistent with the viewpoint that sea level rise is poised to flood the Earth’s coasts and shrink her shorelines.
Image Source: Amara Zenati et al., 2024
And coastal expansion isn’t just a local phenomenon. Globally, shorelines have been advancing seaward at a rate of +0.26 m per year since the 1980s, as, despite sea level rise, the “global coastline is prograding” (Mao et al., 2021).
Image Source: Mao et al., 2021
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