by E. Utter, Apt 11, 2023 in ClimateChangeDispatch
According to a recently released study, at the end of the last ice age, parts of an enormous ice sheet covering Eurasia retreated up to 2,000 feet per day.
That rate is the fastest measured to date, far exceeding what scientists previously believed to be the upper limits for ice sheet retreat. [emphasis, links added]
In the new study, lead author Christine Batchelor and her colleagues analyzed former beds of two major ice streams across the Norwegian continental ice shelf dating back 15,000 to 19,000 years ago.
Using ship-borne imagery, the team then calculated the rates of retreat by studying patterns of wavelike ridges along the seafloor.
They hypothesized that the “orderly” ridge patterns they observed may have been created as the front of the glacier bounced on the seafloor from daily tides.
Call me a skeptic, but this doesn’t sound to me like “settled science.”
Nonetheless, Batchelor and crew think the finding may shed light on how quickly ice in Greenland and Antarctica might melt — and raise global sea levels — in a warming world.
Batchelor stated: “If temperatures continue to rise, then we might have the ice being melted and thinned from above as well as from below, so that could kind of end up with a scenario that looks more similar to what we had [off] Norway after the last glaciation.”
According to a story in The Washington Post, Eric Rignot, a glaciologist who was not involved in the study, opined on it anyway, stating via email:
“This is not a model. This is real observation. And it is frankly scary. Even to me.” (Cue the voice of Elmer Fudd. “Yes, it is vewy, vewy, scawy, Rignot.” Not.
The only thing the study proves is that the Earth warmed quickly and dramatically eons ago— without any possible help from man.
by D.W. Euring, May 20, 2020 in PrincipiaScientificInternational
It became apparent from investigation of the Variability of the Gravitational Constant that Jupiter’s orbit is affecting the Sun’s surface temperature and driving the Sunspot Cycle which appear to be triggered at its Aphelion and suppressed at Perihelion.
Saturn has even greater eccentricity than Jupiter and it is noted that it was at Perihelion at the end of 1972 which seems to account for the Low Solar Maximum at that time and a particular dip after the main peak. So, whilst cycle periods are not influenced by Saturn, it does impact on their magnitude, and it seems likely that it will have augmented in 1957-58 as well as 1990.
by K. Richard, December 24, 2018 in NoTricksZone
Between 60 and 40 thousand years ago, during the middle of the last glacial, atmospheric CO2 levels hovered around 200 ppm – half of today’s concentration.
Tree remains dated to this period have been discovered 600-700 meters atop the modern treeline in the Russian Altai mountains. This suggests surface air temperatures were between 2°C and 3°C warmer than today during this glacial period.
Tree trunks dating to the Early Holocene (between 10.6 and 6.2 thousand years ago) have been found about 350 meters higher than the modern treeline edge. This suggests summer temperatures were between 2°C and 2.5°C warmer than today during the Early Holocene, when CO2 concentrations ranged between about 250 and 270 ppm.
None of this paleoclimate treeline or temperature evidence correlates with a CO2-driven climate.
by Rice University, November 19, 2018 in ScienceDaily
Their study in the journal Geophysical Research Letters is based on an analysis of fossil signatures from deep ocean sediments, the magnetic signature of oceanic crust and the position of the mantle “hot spot” that created the Hawaiian Islands. Co-authors Richard Gordon and Daniel Woodworth said the evidence suggests Earth spun steadily for millions of years before shifting relative to its spin axis, an effect geophysicists refer to as “true polar wander.”
“The Hawaiian hot spot was fixed, relative to the spin axis, from about 48 million years ago to about 12 million years ago, but it was fixed at a latitude farther north than we find it today,” said Woodworth, a graduate student in Rice’s Department of Earth, Environmental and Planetary Sciences. “By comparing the Hawaiian hot spot to the rest of the Earth, we can see that that shift in location was reflected in the rest of the Earth and is superimposed on the motion of tectonic plates. That tells us that the entire Earth moved, relative to the spin axis, which we interpret to be true polar wander.”
La géologie, une science plus que passionnante … et diverse