Via Eurekalert
BUFFALO, N.Y. — Buffalo’s legendary snowfall totals are largely the result of one unlucky geographic reality: the city sits east of the Great Lakes instead of west.
Anyone who has lived through a winter in Buffalo, Cleveland or any snowbelt city knows that prevailing westerly winds pick up moisture from the lakes and dump lake-effect snow on their eastern shores.
But it wasn’t always that way.
University at Buffalo researchers have uncovered new evidence of an Ice Age wind system that likely pushed lake-effect snow toward the western shores instead.
Evidence of this reverse snowbelt lies in thousands of grooves carved into the Great Lakes landscapes by ancient drifting icebergs. The carved landscapes — many now home to beach towns and farm fields — would have been submerged lakebeds about 15,000 years ago, when the lakes were much larger than they are today.
In a study published in Geology, the researchers mapped over 3,300 of these iceberg plowmarks along Lake Erie, Lake Ontario, Lake Huron and the St. Lawrence River, and found that nearly all of them trend from east to west.
Crucially, the west-moving plowmarks span roughly 17 different lake stages — periods when the Great Lakes varied dramatically in size, shoreline and currents.
“Lake currents alone would have moved these icebergs in a variety of directions. The only thing that could have consistently moved them west would be persistent easterly winds,” says first author Sean Grasing, a master’s student in the Department of Earth Sciences within the UB College of Arts and Sciences.
The easterly winds were likely caused by the Laurentide ice sheet, whose retreat northward at the end of the last Ice Age carved out the Great Lakes’ basins and filled them with glacial meltwater. Even after retreating north, the massive ice sheet would have remained large enough to generate a high-pressure anticyclonic wind system, producing persistent easterly winds for thousands of years.
“Climate-model simulations of the Ice Age atmosphere have long pointed to this kind of wind system, but it’s exciting to find hard physical evidence supporting it,” says corresponding author Jason Briner, professor and associate chair in the Department of Earth Sciences.
The west-moving plowmarks span from about 12,000 to 17,000 years ago — a period of roughly five millennia. That means the areas now home to Buffalo and other snowbelt cities likely experienced far less lake-effect snow during that time, while cities along the western shores of the lakes, like Chicago and Milwaukee, likely received more snow than they do today.
“Not only is this fun for Buffalonians to imagine, but it’s also critically important context for paleoclimate researchers looking for clues about future climate patterns,” Briner says.
Use this interactive map to see if there’s an iceberg scratch mark near you
The study is believed to be the most extensive record to date of ancient iceberg plowmarks across the Great Lakes.
The plowmarks range in size from about a third of a mile to more than six miles long. The longest one identified was 11 kilometers long and located in the St. Lawrence Lowlands north of the Adirondack Mountains, near Potsdam.
Most of the marks are nearly impossible to notice with the naked eye — appearing only as a slight divot in the landscape — but become visible using LiDAR, a remote-sensing technology that maps subtle changes in ground elevation.
To identify the plowmarks, Grasing used a technique known as vertical exaggeration, digitally amplifying subtle changes in topography to make the ancient grooves more visible.
The researchers note that their map only includes plowmarks still visible on the surface. Many others have likely been erased by urban development or buried beneath sediment, while countless more probably remain hidden beneath the modern Great Lakes.
“People who have owned their property for decades may never have noticed these plowmarks because they’re very subtle features,” Grasing says. “Maybe a farmer might recognize one as a part of their field where the soil gets particularly wet.”
Despite their modest appearance today, some of the larger plowmarks could only have been carved by enormous icebergs. The researchers estimate the iceberg that created the plowmark near Potsdam may have been roughly the size of Seneca One Tower in downtown Buffalo.
The sheer scale of the ancient landscape was not lost on the researchers.
“These skyscraper-sized icebergs floating in the much larger Great Lakes would have been a backdrop to Paleo-Indians hunting mastodons and other megafauna,” Grasing says. “It creates a very epic image.”
“The beautiful imagery of these iceberg plowmarks that Sean created are fantastic and so fun to look at,” Briner adds. “It’s not every day you get to work on a research project that has such a high giggle factor.”
At that time, were there lakes, or only ice sheets?
After the ice sheets had retreated north of where the lakes are today, there were lakes.
They were probably the northern edge of the lakes, as they ice sheets themselves were most likely the source of such large icebergs.
There were many lakes. Lake Erie is where one called “Lake Whittelsey” existed. Lake Maumee is the better known and larger lake in the area. Glaciers depress the earth and lakes form at the margins until a low spot is breached allowing for an outlet to develop. The Wabash River, near present-day Fort Wayne, Indiana, was the initial outlet for Lake Maumee.
Maumee, how I love ya, how I love ya my dear old Maumee
On flat terrains there should have been lakes next/ near to those ice sheets all over the place,
as those former ice sheets should have made significant dents into the surface while the existing ice sheets released water en masse.
This may be the reason why northern countries like Canada, Finland, Norway etc have so many lakes.
The upper lakes South of the Niagara escarpment would presumably have been lakes. The St Lawrence and Champlain Valleys, depressed by the weight of the glaciers were covered by the ice sheet then marine for a while until glacial rebound brought them above sea level. But I think the temporary incursion of ocean waters up the St Lawrence toward lake Ontario occurred a bit later in time than we’re talking about here.
In these fields where icebergs once were, lettuce is grown. This is where “iceberg lettuce” got its name. True story.
I guess then that last picture shows than growing “Iceberg Corn”! 😉 🤗 🤔
The authors only “suggest.” Well and good because they never examine the alternative that directional outflow created a current driving iceberg direction.
Yep Icebergs do tend to follow prevailing currents.
Let’s be clear (pedantic**). Glaciers — “whose retreat northward at the end of the last Ice Age carved out the Great Lakes’ basins”
When ice moves it carves out, when it “retreats“, it deposits. The technical term for the concept is “the ablation zone”.
(**doesn’t relate to the content of the research)
Wind pattern reallignment is reported to have been instrumental in the relatively late growth of the Puget Lobe.
Observational evidence that climate models of the Ice Age got something right. A rare “high giggle factor” climate model occurrence.
They got 21st century sea level rise acceleration wrong.
They got 21st century Arctic summer sea ice disappearance wrong.
They create a tropical troposphere hotspot that doesn’t exist.
They have ECS twice that of observational EBM estimates.
NOT funny.
Con-Science from people without Conscience!
Sea level acceleration has been well established in the Scuentific literature
Arctic ice is thinning, and its volume is shrinking as projected
The hotspot was never predicted.
All scientific estimates place ECS at 3C +/-
Are all examples of Warmunist propaganda.
That’s only true when you categorize anything that disagrees with the “consensus” as being not science.
There is no measurable acceleration of sea level rise at any stable tide gauge.
PIOMASS Arctic sea ice volume is steady since 2011.
Hot spot does not exist. And yes, all models do “predict” a higher upper troposphere temperature than reality
In reality, ECS is essentially indistinguishable from zero.
Warren notes that you need to look at it scuentifically.
Do you mean “un-scientifically”..
… like he does? Basing his every comment on unscientific propaganda pap.
You are correct, sea level acceleration has been well established in scientific literature. Unfortunately the ocean doesn’t read scientific literature and so doesn’t follow the scripture of the Holy Church of Climate Catastrophe.
“The hotspot was never predicted.”
We can argue semantics between “predicted” and “simulated (/ hindcast) by computer models” from now until the cows come home … but …
IPCC AR4, 2007, Figure 9.1.
Figure 9.1. Zonal mean atmospheric temperature change from 1890 to 1999 (°C per century) as simulated by the PCM model from (a) solar forcing, (b) volcanoes, (c) well-mixed greenhouse gases, (d) tropospheric and stratospheric ozone changes, (e) direct sulphate aerosol forcing and (f) the sum of all forcings. Plot is from 1,000 hPa to 10 hPa (shown on left scale) and from 0 km to 30 km (shown on right). See Appendix 9.C for additional information. Based on Santer et al. (2003a).
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Rud Istvan : “Observational evidence that climate models … have ECS twice that of observational EBM estimates.”
Warren Beeton : “All scientific estimates place ECS at 3C +/-”
In scientific circles I believe this is known as either a “strawman” or “non sequitur” logical fallacy.
In colloquial English I believe an appropriate term is “bait and switch”.
NB : “All” scientific domains have “maverick” or “outlier” researchers, who nevertheless manage to get published. I have seen reports of “in geological history” estimates of ECS of 5°C (or even 8°C ? … TBC …) per CO2 doubling.
As is so often the case, your use of the word “all” turns out to need (many) qualifiers.
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In the AR6 WG-I report the IPCC showed how their “best estimate” for ECS (and projections for surface warming in 2100) compared against individual climate models in FAQ 7.3, “What is equilibrium climate sensitivity and how does it relate to future warming?”, on page 1025.
A copy of Figure 1 from that FAQ is (hopefully) rendered below.
Notes
– While the “IPCC best estimate” for ECS is indeed 3[.0]°C, not only is the CMIP6 “model ensemble mean” (of 2021) noticeably warmer than 3°C it is warmer … i.e. “wronger” … than the CMIP5 ensemble mean value (from 2013)
– Even after the IPCC filtered out the more extreme “inconsistent with recent historical data” models, the upper limit for individual models is over 5.5°C … close enough to “twice that” for government work
– “But projections in this assessment do not solely rely on models”. The “expert judgement” of the IPCC scientists ended up with their “best estimate” ranges being very close to the CMIP5 ranges in the above Figure.
In most scientific domains an extra 8 (or 42, from Charney in 1979 to 2021) years of research usually result in a “tightening” of any given error range / confidence interval. For the CMIP6 models not only did both averages move further away from the IPCC “best estimate”, the ranges were markedly wider and had to be “clipped” (especially at the “running hot in 2100” end).
Yesterday, after logging out and reloading this page to check, both images dynamically loaded as expected (from 3 or 4 years of similar experiences).
Now the first image only renders if I’m logged in.
The second image (+ the first before logging in) gives a “comment image” link to a Cloudflare “Error 1011 : Access denied. The owner of this website (www.ipcc.ch) does not allow hotlinking to that resource” message.
As it is difficult to imagine a more “in the public domain” set of documents than the IPCC assessment reports I’ll re-load them via my hard disk instead.
AR6 WG1, FAQ 7.3 Figure 1.
AR4 WG1 (2007), Figure 9.1.
All are based more on Modeled Data than actual field measurements too. Using Modeled Data as Empirical Data is Bad Science.
The area also used to be the termination point of of the once great mile high Laurentide Ice Sheet. A massive slow moving Glacier that covered 99% of Canada and Alaska. It was Isostatic rebound from the melting/receding ice sheet that allowed the ground to rise in the first place.
The Earth is a Dynamic Planet for sure.
And let’s not forget that those massive ice sheets managed to melt without the global warming effects of too much fossil fuel consumption by those big bad humans who are currently ruining the planet by using up too much of its natural resources. Incidentally, the mega-fauna like the saber-toothed cats, short-faced bears, long-horned bison, dire wolves, giant sloths, wooly mammoths, American mastodons, etc. went extinct long before an expanding humn population could have thinned their ranks.
“while cities along the western shores of the lakes, like Chicago and Milwaukee”
Er, there were no cities there 17–12,000 years ago.
“The beautiful imagery of these iceberg plowmarks that Sean created are fantastic and so fun to look at,” Briner adds. “It’s not every day you get to work on a research project that has such a high giggle factor.”
I would think that an awful lot of junk climate science has a very high giggle factor….