How the Earth Was Made (or Evolved)

[Astronuc]

The History Channel has developed a series on "How the Earth was made". My wife has been listening to it in the evening and I've caught some of it. Mostly good, but the narration mentions some unnecessary commentary, and in the first program, it gets the description of carbon-14 uptake wrong (it mentions the molecular structure of carbon-14 being a more unstable isotope), so it doesn't rise to the level of quality material for the Earth Science forum. It is the 'nuclear' structure of ¹⁴C that makes it unstable, not the molecular structure. A small but significant error.





Comments on carbon-14 starts at 15:12 and goes through 15:32. The other somewhat inaccurate comment is that carbon-14 is absorbed by the plant (which it is with ¹²C and ¹³C often in the form of CO₂), and then decays at a know rate. Well, 14C is continually decaying, however, it is the uptake of CO₂ and ¹⁴C that stops when a plant dies, and ¹⁴C continues to decay, so what changes are the ratios of ¹⁴C to ¹³C and ¹²C as time goes on. The basis also include the notion that the carbon ratios are relatively constant in the environment, but that can change slightly depending on solar proton, cosmic radiation, atmospheric nuclear weapons testing, and apparently comets.

https://www.geo.arizona.edu/Antevs/ecol438/radiocarbon.html
https://www.nature.com/articles/srep03728

Nevertheless, there is some good information and the topics are interesting.

 

[Astronuc]

The Deepest Place on Earth | How the Earth Was Made (S1, E2)
The Marianas Trench explored

 

[Astronuc]

Krakatoa: Devastating Explosion | How the Earth Was Made (S1, E3)





There is some interesting discussion about sulfuric acid in ice from Antarctica. Ice cores show layers, which like tree rings, represent annual records. Apparently there is a layer with increased sulfuric acid content around 535 CE, which would indicate a very large eruption. Year 536 had a long cold period. The eruption of Krakotoa (Krakatau) in 1883 caused a similarly large spike in sulfuric acid in the Antarctic.

https://en.wikipedia.org/wiki/Volcanic_winter_of_536

Summer temperatures in 536 fell by as much as 2.5 degrees Celsius (4.5 degrees Fahrenheit) below normal in Europe. The lingering impact of the volcanic winter of 536 was augmented in 539–540 when another volcanic eruption caused summer temperatures to decline as much as 2.7 degrees Celsius (4.9 degrees Fahrenheit) below normal in Europe. There is evidence of still another volcanic eruption in 547 which would have extended the cooler period. The volcanic eruptions, accompanied by the Plague of Justinian, which began in 541, caused crop failures, famine, and millions of deaths and initiated the Late Antique Little Ice Age, which lasted from 536 to 660.

I have been under the impression that the volcanic eruption responsible for the 536 climate had occurred in Iceland.

 

[Astronuc]

Something I did not know. What is now New York and Connecticut were once connected to Scotland! Hills on the Western side of Loch Ness are composed of the same rock as that in the Catskill Mountains. The two regions were connected during the Jurassic period, but separated with the formation of the Atlantic Ocean. Scotland was apparently about 2000 miles south of its present location.



How the Earth was made, Loch Ness


https://www.geolsoc.org.uk/Policy-and-Media/Outreach/Plate-Tectonic-Stories/Great-Glen-Fault

https://thecatskillgeologist.com/2017/03/30/brick-red-strata-3-30-17/
https://www.earthmagazine.org/article/travels-geology-hiking-catskill-mountain-front/

The layers of red and honey-coloured sandstone that make up the cliffs are between 380 and 370 million years old and date from the Devonian Period, when Scotland lay south of the equator and was part of a huge desert continent. The rocks that formed on this ancient landmass are traditionally known as the Old Red Sandstone. In Devonian times the area including modern-day Orkney, Shetland and north-east mainland Scotland was part of a large depression known as the Orcadian Basin. The rocks that formed in this basin, on desert plains and in lakes, salt flats, dunes and rivers, are preserved today in Orkney to dramatic effect.

https://www.scottishgeology.com/best-places/hoy-orkney/

The Old Red Sandstone is an assemblage of rocks in the North Atlantic region largely of Devonian age. It extends in the east across Great Britain, Ireland and Norway, and in the west along the northeastern seaboard of North America. It also extends northwards into Greenland and Svalbard.[

https://en.wikipedia.org/wiki/Old_Red_Sandstone

https://en.wikipedia.org/wiki/Laurasia#Laurussia

https://en.wikipedia.org/wiki/North_Atlantic_Craton

Another term occurrent in the video is 'Lewisian Gneiss', a suite of Precambrian metamorphic rocks that outcrop in the northwestern part of Scotland, forming part of the Hebridean Terrane and the North Atlantic Craton. These rocks are of Archaean and Paleoproterozoic age, ranging from 3.0–1.7 billion years (Ga).
https://en.wikipedia.org/wiki/Lewisian_complex

I didn't know about "Highlands controversy of Northwest Scotland" either.
https://en.wikipedia.org/wiki/Highlands_controversy_of_Northwest_Scotland

Fascinating stuff!