Saturday, 20 February 2021

Reversal of Earth's magnetic poles may have triggered Neanderthal extinction -- and it could happen again

During this time, Earth's inhabitants would have been subjected to some dazzling displays -- northern and southern lights, caused by solar winds hitting the Earth's atmosphere, would have been frequent.

The reversal of Earth's magnetic poles, along with a temporary breakdown of the world's magnetic field about 42,000 years ago, could have triggered a raft of environmental changes, solar storms and the extinction of the Neanderthals, according to a new study.

The Earth's magnetic field protects us, acting as a shield against the solar wind (a stream of charged particles and radiation) that flows out from the sun. But the geomagnetic field is not stable in strength and direction, and it has the ability to flip or reverse itself.

Some 42,000 years ago, in an event known as the Laschamp Excursion, the poles did just that for around 800 years, before swapping back -- but scientists were unsure exactly how or if it impacted the world. 

Now, a team of researchers from Sydney's University of New South Wales and the South Australian Museum say the flip, along with changing solar winds, could have triggered an array of dramatic climate shifts leading to environmental change and mass extinctions.

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Thursday, 4 February 2021

Europe’s Bronze Age Farmers Adapted to Drought Conditions

(© Archeodunum SA)

GENEVA, SWITZERLAND—According to a statement released by the University of Geneva, a team of scientists led by Alessandra Varalli of Spain’s Pompeu Fabra University has analyzed the biochemical composition of plant remains and the collagen in human and animal bones discovered at Bronze Age sites in western Switzerland and southeastern France. The study suggests that between 2200 and 800 B.C., the people of the region ate mostly plants and land animals, despite the presence of nearby lakes and rivers. The amount of nitrogen in the plant remains indicates that the use of manure as a crop fertilizer became widespread.

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Monday, 1 February 2021

Climate Change In Antiquity: Mass Emigration Due To Water Scarcity

Buried forever by the desert: ruins of Soknopaiou Nesos, a village in the Fayum region
of Egypt that was lost in late antiquity [Credit: Bruno Bazzani/WikiCommons]

The absence of monsoon rains at the source of the Nile was the cause of migrations and the demise of entire settlements in the late Roman province of Egypt. This demographic development has been compared with environmental data for the first time by professor of ancient history, Sabine Huebner of the University of Basel - leading to a discovery of climate change and its consequences.

The oasis-like Faiyum region, roughly 130 km south-west of Cairo, was the breadbasket of the Roman Empire. Yet at the end of the third century CE, numerous formerly thriving settlements there declined and were ultimately abandoned by their inhabitants. Previous excavations and contemporary papyri have shown that problems with field irrigation were the cause. Attempts by local farmers to adapt to the dryness and desertification of the farmland - for example, by changing their agricultural practices - are also documented.

Volcanic eruption and monsoon rains

Basel professor of ancient history Sabine R. Huebner has now shown in the journal Studies in Late Antiquity that changing environmental conditions were behind this development. Existing climate data indicates that the monsoon rains at the headwaters of the Nile in the Ethiopian Highlands suddenly and permanently weakened. The result was lower high-water levels of the river in summer. Evidence supporting this has been found in geological sediment from the Nile Delta, Faiyum and the Ethiopian Highlands, which provides long-term climate data on the monsoons and the water level of the Nile.

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A Viking Archaeologist Shares 6 of the Most Fascinating Finds From a Slew of Recent Discoveries Made in Melting Ice

Archaeologists working to discovered Viking artifacts uncovered by ice melt at the Lendbreen ice patch. Photo courtesy of Secrets of the Ice.

Global warming has unlocked hundreds of Viking artifacts from the ice of the Norwegian mountains in recent years.

In November, archaeologists from the Secret of the Ice project, part of Norway’s Glacier Archaeology Program, discovered 68 arrows spanning a period of 6,000 years—a record for any frozen archaeological site—on the Langfonne ice patch, an ancient Viking hunting ground.

A few months earlier, scientists announced discoveries that had been frozen in the rapidly melting Lendbreen ice patch, which was once part of a Viking trade route.

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