Sea Levels Near B.C. Canada Were 90 Meters Higher Than Today 14,500 Years Ago

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A new study suggests British Columbia (Canada) relative sea levels remained 10 meters higher than they are today until they fell to their present levels in the last ~1800 years. Two other new studies suggest sea levels were still 0.8 to 1 meter higher than today during the Medieval Warm Period.

After the peak of the last glacial about 20,000 years ago, relative sea levels subsequently rose from 120 meters below modern sea levels to heights of 90 meters above today’s by ~14,500 years ago in the Douglas Channel near British Columbia, Canada (Letham et al., 2021).

Sea levels proceeded to fall 75 to 80 meters over the next 3000 years, or about -2.5 meters per century (-25 mm/yr), and then they remained 10-15 m above present for the next ~9000 years.

We determine that central Douglas Channel was ice-free following the Last Glacial Maximum by 14,500 BP and RSL was at least 90 m higher than today. Isostatic rebound caused RSL to fall to 21 m asl by 11,500 BP, though there may have been a glacial re-advance that would have paused RSL fall around the beginning of the Younger Dryas. RSL fell to 10–15 m asl by 10,000 BP, and continued to drop at a slower rate towards its current position, which it reached by ∼1800 years ago.”

Image Source: Letham et al., 2021

Steffen et al., 2020 proposed relative sea levels peaked at 32 meters above today’s levels in Nanotalik (southern Greenland) during the latter stages of the last ice age (13,800 years ago).

Image Source: Steffen et al., 2020

Sea levels were reportedly about 40 meters higher than today 15,000 years ago along the coasts of western Norway (Bondevik et al., 2019).

Image Source: Bondevik et al., 2019

For the Southern Hemisphere, a 2011 study (Watcham et al.) reported Antarctica’s sea levels were at least 15 meters above today’s 9000 years ago. Falling sea levels have been ongoing since then, with an especially pronounced acceleration in declining sea levels in the last 500 years.

Image Source: Watcham et al., 2011

Two more new studies indicate the relative sea levels along the coasts of Bangladesh (Haque and Hoyanagi, 2021) and South China Sea (Yan et al., 2021) were still about 0.8 to 1.2 meters higher than today’s during the Medieval Warm Period.

None of these studies have sea level trajectories that even remotely align with changes in the atmospheric CO2 concentration that ranged from 230 ppm 14,500 years ago to 270 ppm during the Medieval Warm Period.

Haque and Hoyanagi, 2021

“This study illustrates the influences of sea-level on the depositional process during the last 1000 years of the southwestern delta, Bangladesh. … During the 850–1300 AD, RSL [relative sea level] was reached up to +80 cm higher than the present level where tidal-influenced bioturbated light yellow to gray mud deposited in the upper delta plain area. RSL was dropped up to −110 cm during 1300–1850 AD.”

Yan et al., 2021

“Beachrock is considered a good archive for past sea-levels because of its unique formation position (intertidal zone). To evaluate sea-level history in the northern South China Sea, three well-preserved beachrock outcrops (Beigang, Gongshanbei, and Hengling) at Weizhou Island, northern South China Sea were selected to examine their relative elevation, sedimentological, mineralogical, and geochemical characteristics. Acropora branches with well-preserved surface micro-structures were selected from the beachrocks and used to determine the ages of these beachrocks via U-series dating. The results show that the beachrocks are composed of coral reef sediments, terrigenous clastics, volcanic clastics, and various calcite cements. These sediments accumulated in the intertidal zone of Weizhou Island were then cemented in a meteoric water environment. The U-series ages of beachrocks from Beigang, Gongshanbei, and Hengling are 1712–768 ca. BP, 1766–1070 ca. BP, and 1493–604 ca. BP (before 1950 AD) respectively. Their elevations are 0.91–1.16 m, 0.95–1.24 m, and 0.82–1.17 m higher than the modern homologous sedimentary zones, respectively. Therefore, we concluded that the sea-level in the Meghalayan age (1766–604 ca. BP) was 0.82–1.24 m higher than the present, and that the sea-level over this period showed a declining trend.”
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11 responses to “Sea Levels Near B.C. Canada Were 90 Meters Higher Than Today 14,500 Years Ago”

  1. Curious George

    “Sea Levels Near B.C. Canada Were 90 Meters Higher Than Today 14,500 Years Ago.” Probably a typo. Elsewhere, they were 130 meters lower than today.

  2. J N

    In most location where this phenomena happened, has to do with isostasy. Today, lots of locations in Scandinavian peninsula, the se is apparently still retreating but, as a matter of fact, is the landmass that is locally rising. In most location not subjected to the weight of thick sheets of ice, the se was 120 to 140 meters lower than the present level.

    1. The Indomitable Snowman, Ph.D.

      That’s a common phenomenon all over the northern hemisphere in regions that were under a mile-deep ice sheet during the last glacial era. Lake Champlain in the NE US (divides Vermont and New York, and extends north into Quebec) was ocean when the ice melted 10,000 years ago – but is now 100 feet (about 30 meters) above sea level and is still rebounding upward (do the math on the annual rate – something like an inch a year).

      My understanding is that Loch Ness in Scotland has been doing something similar over the past 10,000 years (was ocean, now rebounded up higher and thus became fresh water).

  3. Richard Greene

    90 meters higher sounds like baloney to me.

  4. RoHa

    This is why we have to stop Man Made Global Warming. If it goes on at this rate, all the sea will evaporate and there will be no seas left.

  5. Karsten

    maybe some Letuja Bay event?

  6. Sea Levels Near B.C. Canada Were 90 Meters Higher Than Today 14,500 Years Ago – Watts Up With That?

    […] From the NoTricksZone […]

  7. pochas94

    These papers created severe cognitive dissonance for me. The above comments helped.

  8. J N

    Sorry for the typo errors in my last comment. Beware that these studies relate to relatively high latitude regions. In these locations, at glacial maximum, the weight of the ice led to an isostatic compensation of crustal sinking. Since the glacial maximum, these regions have been on a slow rise. Thus it is not the sea level that is falling but the crust that is slowly rising. Even today, in several circumpolar-polar regions, for instance in Scandinavia, the sea is apparently receding. This is stated in the studies. In the rest of the planet, especially in mid to low latitudes, the sea level was 120-140 metres below the current level and has naturally been rising.
    It seem to be confusing but it is not. The crust is very dynamic horizontally (tectonics) and vertically (tectonics, isostasy, etc.). These studies are perfectly online with the bet geologic knowledge that we have from crustal processes.

  9. pochas94

    The Clovis people arrived in the Western Hemisphere ostensibly 13,500 years ago, over a land bridge between Siberia and North America. From the Letham paper “After the peak of the last glacial about 20,000 years ago, relative sea levels subsequently rose from 120 meters below modern sea levels to heights of 90 meters above today’s by ~14,500 years ago in the Douglas Channel near British Columbia, Canada”

    The story about the arrival of the Clovis people may need work.

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