Marine High Stands During the Sangamonian Interglacial at Myrtle Beach, South Carolina

I’ve always been fascinated with the Sangamonian Interglacial, known as the Eemian Interglacial in Europe. It’s the most recent climate phase when average annual global temperatures were the same or even higher than those of today. No major extinction of megafauna occurred during this phase–the best evidence against climate models of Pleistocene megafauna extinction. The Sangamonian Interglacial lasted from 132,000 years BP-118,000 years BP, although the below referenced study frames it between 128,000 years BP-117,000 years BP. Climate was likely not noticeably different during the discrepancy between these 2 parameters. The north polar ice cap completely melted during the Sangamonian Interglacial, resulting in higher sea levels than today. The north polar ice cap also completely melted during the early Holocene about 10,000 years ago. (Note: and polar bears did not become extinct as alarmists claim will happen.) Scientists are also interested in the Sangamonian because it provides an analogue for today’s climate but without the influence of manmade greenhouse gases. Recently, scientists studied ancient shorelines that existed during the Sangamonian Interglacial at Myrtle Beach, South Carolina. They appear today as ridges or terraces, referred to as outcrops as well, and they consist of crushed consolidated seashells including coral, clams, and oysters. 1 of these outcrops has a layer of peat inside the shelly sediment, suggesting the existence of a marsh, and another 1 has an eolian or windswept sand dune embedded in the layer from dunes that formed during an arid climate cycle.

Location of the area studied in the below referenced paper. Yellow lines represent high stands. Peninsular Florida was mostly submerged with the exception of a few islands. During the Pliocene shoreline was even higher and extended into the middle of South Carolina where the shoreline consisted of sea cliffs. Today, it is the eroded Orangeburg Escarpment.

Another map from the below referenced study showing terraces from former shorelines when sea level was higher than today.

Cold water coral (Desmophyllum pertusum) occurs on the Blake Plateau off the coast of South Carolina. It forms an important ecosystem. Scientists date ancient shorelines using radiometric dating, specifically Uranium series dating of coral found in the terraces.

Ribbon corals, also known as sea whips occur in shallow water off the coast of South Carolina. They are not a true coral.

The scientists dated these old shoreline ridges using uranium series dating from coral fossils and by using optically stimulated luminescence. (See: https://en.wikipedia.org/wiki/Optically_stimulated_luminescence ) They determined sea level rose no more than 15 feet during the early Sangamonian. Throughout the Sangamonian sea level fluctuated between 9-21 feet higher than that of today. Sea level rose rapidly during the early Sangamonian, stabilized, then rose again. Fluctuations were rapid and corresponded with unstable ice sheets. This new study agrees with earlier studies of these marine high stand terraces at other locations. During Ice Ages sea levels retreated as more of earth’s moisture became locked in glaciers, and dry land habitat occurred as much as 50 miles off the modern-day coast.

Reference:

Dean, S.; et al

“Last Interglacial Relative Sea Level Changes at Myrtle Beach, S.C.”

Quaternary Science Review 375 2026 (in progress)

Click to access 125489.pdf

New Study of Avifauna at Panola Mountain State Park

There is an ongoing study of birds at the Panola Mountain State Park in Rockdale County, Georgia located on the outskirts of Atlanta. Panola Mountain State Park is 1600 acres and features an erosion resistant granite monadnock, wetlands, lakes, and a restored grassland. Farmland and a golf course were converted to a grassland starting in 2001 by removing non-native plants and planting native bluestem grasses that originally occurred throughout much of the state. Periodic controlled fires help maintain the native landscape. The grassland is surrounded by forests.

191 species of birds are known to occur in the park and 90 species have been banded here. Scientists capture birds with mist nets that they set up at least once a month from morning until noon, and they’ve been doing this since 2007. The most recent study analyzed evolutionary changes in the birds that live in the park either seasonally or year-round.

Map showing location and banding areas in Panola Mountain State Park. It’s located on the outskirts of Atlanta. From the below referenced study.

Graph showing average annual temperature increase over the past 17 years from a nearby weather station. Also from the below referenced study.

There is an erosion resistant granite monadnock in the park. I will probably visit this park some day.

Restored grassland in the park where birds are captured and studied.

Western palm warblers migrate through the park.

Indigo buntings live year-round in the park. They are vicious little birds. I saw one chasing another bunting into a window. It pecked the stunned bird in the head until it was dead.

Field sparrows and other species of sparrows thrive in the restored grassland.

Average annual temperatures at this locality have increased by 4 degrees F over the past 17 years, according to data from the nearby Jonesboro weather station. Scientists expected changes in local birds that followed Bergman’s Rule and Allen’s Rule. Bergman’s Rule states that species of animals in warmer climates will grow on average to a smaller size than those same species that occur in colder climates. Allen’s Rule states that species of animals in warmer climates will grow longer appendages than their northern cousins. Scientists captured 2,938 birds including 668 recaptures for the body size part of the study. They analyzed 9 species. Gold finches, field sparrows, and savannah sparrows grew smaller wings in contradiction to Allen’s Rule. The other 6 species had unchanged wing lengths. Bergman’s Rule was contradicted by data from 4 species. Scientists hypothesize local variations contributed to these contradictions. Birds often live for part of the year in other locations that may have had different temperatures.

1,128 birds including 45 recaptures were used to study the migratory phenology (the time of year when birds begin their migration). They found 1 species did have an earlier spring migration and 2 species started migrating later in the fall. The study also looked at demographics. 1 species had a higher male sex ratio than previously, and another species had a higher population of juveniles than formerly.

The authors of this paper believe restoring grasslands can help mitigate the detrimental effects of climate change because they see so little change here. In my opinion that is a stretch. It’s a relatively small sample size from just 1 location, and climate has always changed, and those changes are not always detrimental.

Reference:

McMahaon, A.; K. Stumpf and C. Muise

“Changes in Morphology, Phenology, and Demography of Several Avian Species over 18 Years at a Restored Grassland”

Georgia Journal of Science 83 (2) 2025

https://digitalcommons.gaacademy.org/cgi/viewcontent.cgi?article=2774&context=gjs

Climate Models are not Wild Guesses

Whenever I’ve discussed anthropogenic global warming on this blog, I’ve often written climate models were wild guessing. I’ve come across a study that suggests I was wrong. The study looked at 11 scientific papers with 14 projection models that estimated changes in average global temperatures over time. The papers were published between 1970-1993. The authors of this study then compared those projections from the models to average temperatures as of 2017. Though some models slightly overestimated temperatures and others slightly underestimated temperatures, most were remarkably consistent. The models were based on estimates calculating natural climate change plus manmade emissions of CO2 influence.

Climate models were remarkably consistent with real observations. Chart from the below study.

Energy use is projected to increase exponentially in the future, and this means an increase in burning fossil fuel and even greater CO2 emissions. The creation of bitcoins alone equals the energy use of New York state or the country of Poland. I don’t understand how cryptocurrency is even legal. Bitcoin creators are wasting earth’s resources creating artificial wealth out of nothing. Data centers that support internet infrastructure already use almost 5% of the power generated in the world. This computational infrastructure is going to increase as humans rely more and more on robots.

Bitcoin mining uses an enormous amount of energy, creating nothing that is useful for society. A few people will get rich at the expense of a lot of chumps.

Data centers will expand, as humans rely more and more on robots, hence increasing energy use even more.

As more fossil fuel is used, earth’s climate is headed for an uncomfortable atmosphere that resembles what it must have been like for dinosaurs during the Cretaceous Age. There is no reversing this nightmare scenario. People aren’t going to give up driving cars and central heating and air conditioning. (Especially air conditioning, since the world is going to become so much warmer.) Selfish totalitarian rulers don’t care about the environment. Wind and solar won’t be able to provide enough power for the world to end use of fossil fuels. We are doomed to live in a world of misery caused by climate change.

Robots will contribute to an apocalyptic future, but probably not in the way depicted in the Terminator movies. Instead, the energy demand to drive robots will cause global warming that will devastate the atmosphere.

Reference:

Hausfather, Z.; H. Drake, T. Abbott, G. Shmidt

“Evaluating the Performance of Past Climate Model Projections”

Geophysical Research Letters 2021

https://www.semanticscholar.org/paper/Evaluating-the-Performance-of-Past-Climate-Model-Hausfather-Drake/93cf8a01b3674e63a74d983573f05f5136c6ca1d

Pleistocene Insects from the Yukon

Scientists can learn about past climates and environments by studying the insect species composition found in dated layers of sediment. This isn’t possible in most parts of the world because of poor preservation processes, but it is in the Yukon were rapid sedimentation combined with permafrost conditions have preserved insect remains for the past 250,000 years in some localities. This includes 2 full glacial and interglacial climate phases. Today, the Old Crow River valley consists of coniferous forest, wetlands, and wet tundra; but in the past the environment has fluctuated between dry desert grassland during Ice Ages, and open spruce parkland during Interglacial periods. (This region was north of the massive glaciers that covered most of Canada when Ice Ages occurred.) The present day Interglacial is different from previous Interglacial periods because forests are thicker. The extinction of megafauna likely explains why denser forests predominate today. During past Interglacial times herds of horses, camels, mastodons, mammoths, and ground sloths kept woodlands more open.

Location of study area from the below referenced paper.

Insect remains found in sedimentary cores from the Yukon.

A specimen of Dyschirius laevifasciatus was found in a Yukon sediment core. It no longer lives this far north.

A species of rove beetle (not the one in the above photo) that today is only known from the Pacific Coast formerly lived in the Yukon interior. It probably lived on a glacial lake shoreline, similar to the beach zones it occurs in today.

Some fossil insect remains suggests previous Interglacial periods were warmer than the present day Interglacial. Scientists found remains of Dyschirius laevifasciatus, a species of ground beetle that lives much farther south today in sediment layers dating to the Sangamonian Interglacial. Beetles in this genus prefer wet sand habitats, and these remains indicate a glacial lake beach occurred here. They also found remains of a species of rove beetle (Kallisus nitodus) that not only doesn’t live this far north but is today only known from the Pacific Coast. This species formerly was able to range into drier inland habitats. Why its range has contracted is a mystery. Perhaps, it never recolonized the region after a glacial lake dried up.

The insect species composition during previous Interglacial periods differs from present day species composition. There were some species that live in wooded areas–bark beetles, a species of weevil, and a few ant species–but much fewer than today. Even though the climate was warmer and probably wetter than today, forests weren’t as dense, and trees grew farther apart, like a parkland. Steppe grassland species still occurred.

The scientists who authored the below referenced study took sample cores from 4 sites in the Old Crow River Valley. They often encountered ice wedges marking areas when the permafrost melted during previous Interglacial periods. Then the water refroze. The insects were buried in sediment when rivers flooded and when glacial lake levels rose as temperatures increased. The scientists used wet screening to find the subfossil insect parts. Insect exoskeletons float to the surface when sediment is immersed in water. From dozens of sample cores they collected thousands of specimens from over 100 species. Radiocarbon dating can only be used for organic material that is younger than 50,000 years, but insect species composition can be used in conjunction with other methods to date sedimentary layers older than this. Layers with mostly steppe grassland species indicate Ice Ages, and layers with some woodland species indicate Interglacial periods.

Though climate changed in the Yukon, evidence from this study suggests it has changed less here than in other regions of the world. The Yukon is near the Arctic Circle and has remained cold for millions of years.

Kazima, S. et. al.

“Middle Pleistocene (MIS 5) to Holocene Fossil Insect Assemblages from the Old Crow Basin, Northern Yukon, Canada”

Quaternary International 341 August 2014

https://www.researchgate.net/publication/329626444_Middle_Pleistocene_MIS_7_to_Holocene_fossil_insect_assemblages_from_the_Old_Crow_basin_northern_Yukon_Canada