Post by UKarchaeology on Jul 13, 2015 15:18:31 GMT
On March 24 536AD the sky suddenly darkened across continental Europe as a thick dust cloud rolled in and stayed put for 18 months
On March 24 536AD the sky suddenly darkened across continental Europe as a thick dust cloud rolled in and stayed put for 18 months.
Historians such as Prokopios record that the Sun shone as dimly as the Moon, sparking summer frosts and snow showers and providing too little light to ripen crops and fruit. Three years later a similar dust veil blocked out sunlight for several months.
The natural catastrophes led to widespread famine and was responsible for the Great Justinian Plague which wiped out one third of Europeans and probably dealt the fatal blow to the struggling Roman Empire.
Now scientists have determined that the cause was probably a series of North American volcanoes which shot huge amounts of sulphate and ash into the atmosphere, followed by further eruptions in the Tropics.
New studies of ice cores and historical records by the British Antarctic Survey, Nottingham University and 17 other international universities and institutions, show that there was a huge volcanic eruption in 535AD or early 536AD in North America. A second eruption occurred in 539AD.
The volcanic activity was ruinous for Mediterannean communities. Cassiodorus, a praetorian prefect in Italy wrote that the country had ‘a winter without storms, spring without mildness, summer without heat".
The climatic effects of the dust veil brought plummeting temperatures, drought and food shortages throughout the affected regions and in Europe two years later sparked the Justinian Plague of 541AD to 543AD, which killed one third of the continent’s population.
The plague was seen by many historians as the final blow for the flailing Roman Empire which had already lost much of its power and influence.
“Our new dating allowed us to clarify long-standing debates concerning the origin and consequences of the severe and global climate anomalies which began with the mystery cloud in 536AD observed in the Mediterranean basin, “said the study author Dr Michael Sigl, assistant research professor at Desert Research Institute in Reno and the Paul Scherrer Institute in Switzerland.
"We found at least two large volcanic eruptions around this period.
"These cooler temperatures were caused by large amounts of volcanic sulphate particles injected into the upper atmosphere shielding the Earth's surface from incoming solar radiation.
“This provides notable environmental context to widespread famine and the great Justinian Plague of 541-543A that was responsible for decimation populations in the Mediterranean.”
The study shows that 15 of the 16 coldest summers recorded between 500 BC and 1,000 AD followed large volcanic eruptions - with four of the coldest occurring shortly after the largest volcanic events found in record.
The new reconstructions is derived from more than 20 individual ice cores extracted from ice sheets in Greenland and Antarctica and analysed for volcanic sulphate.
"Ice-core timescales had been misdated previously by five to ten years during the first millennium leading to inconsistencies in the proposed timing of volcanic eruptions relative to written documentary and tree-ring evidence recording the climatic responses to the same eruptions," said Dr Francis Ludlow, of the Yale Climate & Energy Institute.
Together with Dr Conor Kostick from the University of Nottingham, Ludlow translated and interpreted ancient and medieval documentary records from China, Iraq and Europe that described unusual atmospheric observations as early as 254 years before Common Era (BCE).
These phenomena included diminished sunlight, discoloration of the Sun the presence of solar haloes, and deeply red twilight skies.
The research was published in the journal Nature.
(Source: www.telegraph.co.uk/news/science/science-news/11726459/Did-American-volcanoes-trigger-fall-of-Roman-Empire.html )
On March 24 536AD the sky suddenly darkened across continental Europe as a thick dust cloud rolled in and stayed put for 18 months.
Historians such as Prokopios record that the Sun shone as dimly as the Moon, sparking summer frosts and snow showers and providing too little light to ripen crops and fruit. Three years later a similar dust veil blocked out sunlight for several months.
The natural catastrophes led to widespread famine and was responsible for the Great Justinian Plague which wiped out one third of Europeans and probably dealt the fatal blow to the struggling Roman Empire.
Now scientists have determined that the cause was probably a series of North American volcanoes which shot huge amounts of sulphate and ash into the atmosphere, followed by further eruptions in the Tropics.
New studies of ice cores and historical records by the British Antarctic Survey, Nottingham University and 17 other international universities and institutions, show that there was a huge volcanic eruption in 535AD or early 536AD in North America. A second eruption occurred in 539AD.
The volcanic activity was ruinous for Mediterannean communities. Cassiodorus, a praetorian prefect in Italy wrote that the country had ‘a winter without storms, spring without mildness, summer without heat".
The climatic effects of the dust veil brought plummeting temperatures, drought and food shortages throughout the affected regions and in Europe two years later sparked the Justinian Plague of 541AD to 543AD, which killed one third of the continent’s population.
The plague was seen by many historians as the final blow for the flailing Roman Empire which had already lost much of its power and influence.
“Our new dating allowed us to clarify long-standing debates concerning the origin and consequences of the severe and global climate anomalies which began with the mystery cloud in 536AD observed in the Mediterranean basin, “said the study author Dr Michael Sigl, assistant research professor at Desert Research Institute in Reno and the Paul Scherrer Institute in Switzerland.
"We found at least two large volcanic eruptions around this period.
"These cooler temperatures were caused by large amounts of volcanic sulphate particles injected into the upper atmosphere shielding the Earth's surface from incoming solar radiation.
“This provides notable environmental context to widespread famine and the great Justinian Plague of 541-543A that was responsible for decimation populations in the Mediterranean.”
The study shows that 15 of the 16 coldest summers recorded between 500 BC and 1,000 AD followed large volcanic eruptions - with four of the coldest occurring shortly after the largest volcanic events found in record.
The new reconstructions is derived from more than 20 individual ice cores extracted from ice sheets in Greenland and Antarctica and analysed for volcanic sulphate.
"Ice-core timescales had been misdated previously by five to ten years during the first millennium leading to inconsistencies in the proposed timing of volcanic eruptions relative to written documentary and tree-ring evidence recording the climatic responses to the same eruptions," said Dr Francis Ludlow, of the Yale Climate & Energy Institute.
Together with Dr Conor Kostick from the University of Nottingham, Ludlow translated and interpreted ancient and medieval documentary records from China, Iraq and Europe that described unusual atmospheric observations as early as 254 years before Common Era (BCE).
These phenomena included diminished sunlight, discoloration of the Sun the presence of solar haloes, and deeply red twilight skies.
The research was published in the journal Nature.
(Source: www.telegraph.co.uk/news/science/science-news/11726459/Did-American-volcanoes-trigger-fall-of-Roman-Empire.html )