What was the worst about 2018

Was 536 the worst year in history?

There are several candidates for the most terrible year of our era: 1914 and 1939, the years at the beginning of the First and Second World Wars, are just as possible as the year 1349, when the plague wiped out half of Europe, or 1918, when the Spanish flu up to around the world Carried away 100 million.

For the American medieval historian and archaeologist Michael McCormick of Harvard University, it is another year that he believes was the worst for mankind in the past two millennia: 536. As a medievalist, McCormick has a particular preference for the Middle Ages to have. But he provides good reasons for his choice in the online edition of "Science": This year marked the beginning of the darkest and coldest decade of at least the past 2,300 years - at least in large parts of the northern hemisphere including China.

Snow in summer

The historians Prokopios, Michael the Syrian or Flavius ​​Cassiodor unanimously report low temperatures with snow in summer as well as dramatic crop failures. In the words of Prokopios: "The sun, without radiance, shone like the moon all year round and gave the impression that it was almost completely darkened. Since then, however, the sign has been seen, neither war nor plague nor anything else has been heard an evil that brings death to man. "

This meant, for example, that from 541 the bubonic plague spread from the Roman port of Pelusium in Egypt, probably wiping out almost half of the population of the Eastern Roman Empire and accelerating its collapse.

"Weather anomaly of 535/536"

In the specialist literature, the beginning of this catastrophe is known as the "Weather anomaly of 535/536As climate historians reconstructed using tree rings in the 1990s, temperatures fell by an average of around 2.5 degrees Celsius in the summer of 536 and in the years thereafter.

What triggered the persistent darkening of the sky and the subsequent cold spell, however, is unclear: once asteroid impacts in Australia were blamed, then again volcanic eruptions. In any case, it remained unclear where the devastating eruptions could have occurred.

Search for the "causer"

But now a team led by McCormick and the glaciologist Paul Mayewski (University of Maine) could have found the "culprit". At a workshop at Harvard this week, the researchers reported that a catastrophic volcanic eruption in Iceland in early 536 may have spread ash across the northern hemisphere. Two more massive eruptions then apparently followed in 540 and 547.

Polar ice cores from Greenland and the Antarctic had already provided initial clues. As Michael Sigl (Uni Bern) and other of his colleagues showed, traces of sulfur and other substances in the ice in comparison with the tree rings indicate that almost every unusually cold summer of the last 2,500 years has been accompanied by a volcanic eruption.

72 meter long ice core from the glacier

Mayewski and his interdisciplinary team looked for these eruption traces for their new investigation on the glacier of the 4453 meter high Colle Gnifetti in the Swiss Alps. A 72-meter-long ice core, which was unearthed there in 2013, contains valuable climatological information about the past 2,000 years - regardless of whether it is traces of volcanic eruptions, dust storms from the Sahara or human activities in central Europe.

A new, extremely high-resolution method enabled the team to identify two microscopic particles of volcanic glass that date back to 536. On the other hand, their chemical fingerprint suggested that the particles had probably reached Central Europe from an Icelandic volcano, as the scientists at Harvard reported.

In order to be able to say with absolute certainty, however, further comparative studies are necessary.

Confirmation of the method

A new study by researchers working with Christopher Loveluck (University of Nottingham) in the specialist journal "Antiquity" shows how well this method works in the meantime: They found that a particularly large number of lead particles were found in the ice at Colle Gnifetti from around the year 640 onwards. This in turn indicates that much of the silver was melted from lead ore.

The interpretations of the traces from the Eternal Ice, however, go even further: the researchers suspect firstly that the traces of silver mining come from Melle in France and, secondly, see them as evidence that the money economy switched from gold to silver during this time. Almost exactly a century after what may have been the worst year in history. (Klaus Taschwer, November 17, 2018)