Open Veils · Answer
How long ago did the sea reach 90 feet below today?
A drop of 90 feet (roughly 27 meters) below present was crossed somewhere between approximately 14,000 and 16,000 years ago as post-LGM deglaciation was accelerating. The 90-foot mark is not a single clean date but a threshold the rising sea passed through during one of the most rapid melt pulses in the geologic record — Meltwater Pulse 1A. This window sits squarely within the period when vast inhabited coastlines were being permanently inundated.
Evidence
- The Last Glacial Maximum placed sea level around 125 meters below present circa 21,000 years ago, per USGS figures cited in geological literature.
- Randall Carlson, working from glaciological and sedimentological data, correlates accelerated sea-rise episodes with the Younger Dryas boundary events and earlier melt pulses, arguing that the rise was episodic and punctuated — not gradual.
- Robert Schoch similarly notes that the rapid inundation of shallow continental shelves during this period would have obliterated coastal archaeological evidence, explaining the apparent absence of pre-Holocene coastal cultures in the mainstream record.
- Doggerland, the North Sea plain connecting Britain to Europe, was still a substantial inhabited landscape at sea levels 90 feet below today, as reconstructed via seismic surveys and confirmed by Neolithic-era artifacts dredged from the North Sea floor.
- From that nadir, deglaciation drove sea level upward in an uneven staircase punctuated by discrete surge events.