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Holocene Thermal Optimum and Sea Level

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Narrabeen Man - Catalyst. Narration: This is a story of a most remarkable death, a long time ago, and a very unremarkable location. Dr Paul Willis: On this spot 4000 years ago there was a particularly grizzly death. It was a very violent event that is the earliest recorded ritualised killing in Australia. Forensic science and modern indigenous culture have combined to work out what happened here at the Octavia Street bus stop. Narration: The startling discovery occurred here at Narrabeen on Sydney's northern beaches in January 2005 when contractors were digging a trench for electricity cabling.

After a trip to Glebe Coroner's Morgue the remains were turned over to archaeologist Jo MacDonald ...and a forensic process followed... Dr Macdonald: A find exactly like this has never been found before in Australia. Narration: The first thing that Jo needed to do was to establish the time of death. Dr Macdonald: The date came back at about 4000 years ago, which was quite spectacular we were very surprised. Less Ice In Arctic Ocean 6000-7000 Years Ago -- ScienceDaily. Recent mapping of a number of raised beach ridges on the north coast of Greenland suggests that the ice cover in the Arctic Ocean was greatly reduced some 6000-7000 years ago.

The Arctic Ocean may have been periodically ice free. ”The climate in the northern regions has never been milder since the last Ice Age than it was about 6000-7000 years ago. We still don’t know whether the Arctic Ocean was completely ice free, but there was more open water in the area north of Greenland than there is today,” says Astrid Lyså, a geologist and researcher at the Geological Survey of Norway (NGU).

Shore features Together with her NGU colleague, Eiliv Larsen, she has worked on the north coast of Greenland with a group of scientists from the University of Copenhagen, mapping sea-level changes and studying a number of shore features. She has also collected samples of driftwood that originated from Siberia or Alaska and had these dated, and has collected shells and microfossils from shore sediments. 19 Papers Published In 2019 Affirm Sea Levels Were METERS Higher Than Today 4-8 Thousand Years Ago. The onslaught of paleoclimate evidence for warmer-than-now Mid-Holocene climates – when the Earth’s sea levels were meters higher than they are today – stormed through 2019.

There were 107 scientific papers published this past year indicating today’s warmth isn’t even close to being unusual or unprecedented when compared to the climates of the last centuries to millennia. As illustrated below, there were also 19 papers affirming today’s sea levels are among the lowest of the last ~8000 years. This is added to the list of nearly 100 scientific papers published in the last handful of years indicating Mid-Holocene sea levels were multiple meters higher than they are today due to the much more extensive glacier and ice sheet melt occuring during these millennia.

Oliver and Terry, 2019 Thailand, +2.0 to 3.8 m higher than present Brooke et al., 2019 Queensland (NE Australia), +1-2 m higher than present Yamano et al., 2019 SW Japan, +1.1 to 1.2 m higher than present. Rapidly Fluctuating India Sea Levels Were 4 m Higher Than Today 6000 Years Ago, 1.5 m Higher 500 Years Ago. By Kenneth Richard on 18. July 2019 Scientists have found sea levels on India’s eastern coast were still 1-1.5 m higher than today as recently as 500 to 300 years ago and 3-4 m higher than today between 6000 to 4000 years ago.

Seas rose and fell by multiple meters (-5 m to +3 m) within 1250 years until as recently as 4000 to 2000 years ago. A new paper (Loveson and Nigam, 2019) reveals sea levels were still rising at a rate of 2.2 meters per century between 8100 and 7200 years ago, reaching a highstand of 4 meters above today’s sea level 6050 years ago. For the next several millennia sea levels rapidly rose and fell within a range 6 meters – between 4 meters above to -2 meters below present levels. A drop in sea level at one point reached an amplitude of -5 meters in just 1250 years (4350 to 3100 years ago) followed by 3 meters of sea level rise within 1200 years (3100 to 1900 years ago). Image Source: Loveson and Nigam, 2019 Image Source: BBC Image Source: Makwana et al., 2019. 'Reconstruction' begins of stone age lands lost to North Sea | Science.

Lost at the bottom of the North Sea almost eight millennia ago, a vast land area between England and southern Scandinavia which was home to thousands of stone age settlers is about to be rediscovered. Marine experts, scientists and archaeologists have spent the past 15 years meticulously mapping thousands of kilometres under water in the hope of unearthing lost prehistoric tribes. On Wednesday a crew of British and Belgian scientists set off on their voyage across the North Sea to reconstruct the ancient Mesolithic landscape hidden beneath the waves for 7,500 years.

The area was submerged when thousands of cubic miles of sub-Arctic ice started to melt and sea levels began to rise. The ancient country, known as Doggerland, which could once have had great plains with rich soils, formed an important land bridge between Britain and northern Europe. It was long believed to have been hit by catastrophic flooding. Gaffney said they were praying for stable weather and good luck.

Huge Database Of Studies Documenting Meters-Higher Mid-Holocene Sea Levels Swells Again In 2020. In 2020, scientists continued to publish papers affirming global sea levels are today about 2 meters lower than they were a few thousand years ago. During the last interglacial (~116 to 128 thousand years ago), when CO2 peaked at just 280 ppm but surface temperatures were so much warmer that much less water was locked up on land as ice, sea levels were “at least ~7 m to ~9 m above present” and they “could have been as high as 11-13 m above present” at some locations (Muh et al., 2020).

“Corals with closed-system histories collected from patch reefs on NPI have ages of 128-118 ka and ooids/peloids from beach ridges have closed-system ages of 128-116 ka. Elevations of patch reefs indicate a LIG paleo-sea level of at least ∼7 m to ∼9 m above present. Beach ridge sediments indicate paleo-sea levels of ∼5 m to ∼14 m (assuming subsidence, ∼7 m to ∼16 m) above present during the LIG. …. Since 2019, over 40 new studies have been added to the NoTricksZone sea level database:

Scientists Assert Relative Sea Levels Were 32 Meters Higher Than Today In South Greenland 13,800 Years Ago. By Kenneth Richard on 8. October 2020 Prior to the transition from the last ice age to the current interglacial climate, when CO2 levels still lingered below 250 ppm, the relative sea levels in southern Greenland were “at least ∼32 m above present.” Relative sea levels have undergone a series of major changes since the last glacial maximum, when global sea levels were 120 meters below today’s.

Sea levels rose at rates of up to 60 or 70 millmeters per year (6 to 7 meters per century, Tanabe, 2020) from about 12,000 to 8,000 years ago. Most of the globe experienced sea level high stands of 2 or 3 meters above present between about 7,000 to 5,000 years ago (King et al., 2020, Lopes et al., 2020, Martins et al., 2020). But a new study (Steffen et al., 2020) proposes relative sea levels instead 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 Image Source: Tanabe, 2020.

The Holocene Sea Level Highstand. Guest geological note by David Middleton Most skeptics are familiar with the Warmunist efforts to erase the Medieval Warm Period and Little Ice Age. However, many skeptics may not be aware of efforts to erase another paleoclimatological feature: The Holocene Highstand. What is a highstand? A highstand is one phase of the sea level cycle (AAPG Wiki) RisingHighstandFallingLowstand The highstand is the maximum sea level achieved during the cycle. The Holocene Epoch The Holocene Epoch was recently formally subdivided into three stages: Greenlandian Stage = Lower or Early-Holocene. 11.70 ka to 8.33 ka Northgrippian Stage = Middle or Mid-Holocene. 8.33 ka to 4.25 ka Meghalayan Stage = Upper or Late-Holocene. 4.25 ka to present The abbreviation “ka” refers to thousands of years ago.

There is also an informal climatological subdivision of the Holocene: Preboreal 10 ka–9Boreal 9 ka–8 kaAtlantic 8 ka–5 kaSubboreal 5 ka–2.5 kaSubatlantic 2.5 ka–present Source: Wikipedia References Brock, J.C., M. Haile, N.S. Asian sea levels changed rapidly 6,000 years ago — natural sea level rise “unprecedented” If you thought seas were constant 6,000 years ago… Microatolls are apparently very accurate proxy for sea levels, giving a higher resolution estimate of sea levels. But the extra data suggests more natural oscillations in seas than the experts used to think. Six thousand years ago, near Indonesia, seas apparently rose and fell twice by as much as 60 centimeters in a 250 year period. A similar pattern happened 2,600km away in SE China. Seas were changing so fast researchers estimate the shift occurred at 13mm per year and comment that these regional changes are “unprecedented in modern times.”

(Or unrepeated, perhaps?) At the first peak 6,750 years ago, seas were 1m higher than today. From the paper I gather that sea levels in this region change a lot even now. You and I might think this shows that the climate changes all by itself (and CO2 was irrelevant). If they’d found no swings, presumably the press release would tell us how the modern 1mm a year rises are unprecedented.

. – Jo. Inconvenient Climate History: South African Sea Levels 3 Meters Higher 5000 Years Ago. By P Gosselin on 27. June 2018 South Africa Sea Level Was 3 Meters Higher 5000 Years Ago Than Today By Dr. Sebastian Lüning and Prof. Today’s topic: Sea level rise around Africa. That makes sense because during the warm phases ice melts at the poles and high mountains glaciers.

There is good evidence for a number of environmental shifts during the last 2000 years, but the most noteworthy event may be the climatic fluctuation during the Little Ice Age (LIA) period. Also on the west coast of South Africa we find a small surprise. Sea level of the west coast of South Africa during the past 9000 years (BP=years before present). Next let’s move northeast to Mozambique. The complete picture of Maputo Bay patterns with its modern sedimentary environments including Inhaca Island may have evolved when the sea level has stood close to its present level around 7000 – 5000 years BP, after which the Maputo Bay became more or less stable.” Oyster Evidence Affirms Sea Levels Were Up To 3.8 Meters Higher Than Today 6000 Years Ago. By Kenneth Richard on 7. February 2019 According to a new paper (Oliver and Terry, 2019) published in Palaeogeography, Palaeoclimatology, Palaeoecology, oyster remains have been found encrusted in rock 2.5 to 3.8 meters above the present mean sea level.

This fossilized evidence dates to ~6000 to years ago, a period when the Earth’s surface temperatures were 4-6°C warmer than they are today. Image(s) Source: Oliver and Terry, 2019 The evidence provided by Oliver and Terry (2019) will be added the to growing list of more than 80 scientific papers indicating sea levels from locations throughout the world were meters higher than they are today just a few thousand years ago. 80+ Papers: Mid-Holocene Sea Levels Were Multiple Meters Higher Than Today Oliver and Terry, 2019 Relative sea-level highstands in Thailand since the Mid-Holocene based on 14C rock oyster chronology • “In all the sites, the 14C age of the dead oysters inside the notches increases with increasing elevation above present day MSL.

Scientists Find Caribbean Sea Levels Were 1 Meter Higher 5300 Years Ago…Today Rising More Slowly. By P Gosselin on 8. July 2018 5300 years ago sea level near Surinam and Guyana was about 1m higher than today By Dr. Sebastian Lüning and Prof. Fritz Vahrenholt (German text translated/edited by P. Gosselin) A paper authored by Khan et al. 2017 looked at the Caribbean over the past 10,000 years. After the end of the last ice age some 11,000 years ago, sea level rose around Surinam and Guyana at a rate of 11 mm per year. During the middle and late Holocene, i.e. over the past 5000 years, sea level rise was only 2.4 mm per year. Drivers of Holocene sea-level change in the Caribbean We present a Holocene relative sea-level (RSL) database for the Caribbean region (5°N to 25°N and 55°W to 90°W) that consists of 499 sea-level index points and 238 limiting dates.

Holocene Sea Level Trends. By Paul Homewood There seems to be a general acceptance about overall sea level trends during the Holocene. There was naturally a very rapid rise in sea levels at the end of the ice age, until 6000 years ago, since when the rise has been much more gradual. Some research puts the rate of rise in the last 2000 years at 0.07mm/yr, and this reflects the fact that ice caps left over from the ice age are still melting, rather than that the world is warmer than before. However, the impression is often given that, until the 20thC, this rate of rise has been pretty steady. This is despite the fact some of the authors of the above studies have warned of the existence of significant short-term fluctuations in sea level such that the sea level curve might oscillate up and down about this ~1 kyr mean state.

[The above graph is based around 1000 year averages]. 2) The water level may have dropped by 2 metres or more between 2000 and 500 BC. Several New Papers Indicate Sea Levels Were 1 – 3 Meters Higher Than Today A Few Thousand Years Ago. By Kenneth Richard on 14. May 2020 Both during the last interglacial (~120,000 years ago) and from roughly 2000 to 7000 years ago, relative sea levels were from 6-10 meters to 1-3 meters higher than they are today, respectively. For a list of over 100 other scientific papers indicating sea levels across the world were multiple meters higher when Earth’s CO2 concentrations were about 150 ppm lower than they are today (~260 ppm), see our database here. The Mid-Holocene, 2000-7000 years ago Lopez-Belzunce et al., 2020 (Mediterranean) “Regarding the stabilization of the RSL [relative sea level], our data show it to be 1.20 m above the present-day level at 3000 cal yr BP and 1 m higher at 2000 cal yr BP.” Burley et al., 2020 (Polynesia) “At the time of first Lapita arrival at Nukuleka, sea levels were 1.2–1.4 m higher than present (Dickinson 2007).”

Lopes et al., 2020 (Brazil) Image Source: Lopes et al., 2020 Brocx and Semeniuk, 2020 (Western Australia) Helfensdorfer, 2020 (Australia) New Study: Denmark Sea Level Was 11-12.5 Meters Higher Than Now During The Mid-Holocene. By Kenneth Richard on 21. June 2018 In a new paper, data from 57 sites along 17 km of coastal Denmark reveal that sea levels were 11 to 12.5 meters higher than they are today between 7,600 and 4,600 years ago. Image Source: Clemmensen et al., 2018 Most Holocene reconstructions do not indicate that sea levels were more than about 5 meters above present between about 9,000 to 4,000 years ago. But a new study utilizing well-preserved beach facies along the coasts of northern Denmark indicates that sea levels were as much as 12.5 meters higher than they are today during the Mid-Holocene. These extremely high sea level elevation values may be less common, but other research has revealed that sea levels were as much as 8 meters higher than today near East Antarctica (Hodgson et al., 2016) during the Early Holocene.

A high-resolution sea-level proxy dated using quartz OSL from the Holocene Skagen Odde spit system, Denmark Conclusion: 35 Scientific Papers: Global Sea Levels Were 1 – 2 Meters Higher Than Now For Most Of The Last 7,000 Years. New Paper: Widespread Collapse Of Ice Sheets ~5000 Years Ago Added 3-4 Meters To Rising Seas.