Aug 2, 2021 08:18 PM
(This post was last modified: Aug 3, 2021 04:07 PM by C C.)
Doggerland: 'Lost Atlantis' of the North Sea gives up its ancient secrets
https://www.theguardian.com/science/2021...nt-secrets
INTRO: The idea of a “lost Atlantis” under the North Sea connecting Britain by land to continental Europe had been imagined by HG Wells in the late 19th century, with evidence of human inhabitation of the forgotten world following in 1931 when the trawler Colinda dredged up a lump of peat containing a spear point.
But it is only now, after a decade of pioneering research and the extraordinary finds of an army of amateur archaeologists scouring the Dutch coastline for artefacts and fossils, that a major exhibition is able to offer a window into Doggerland, a vast expanse of territory submerged following a tsunami 8,000 years ago, cutting the British Isles off from modern Belgium, the Netherlands and southern Scandinavia.
The exhibition, Doggerland: Lost World in the North Sea, at the Rijksmuseum van Oudheden (National Museum of Antiquities) in Leiden, southern Holland, includes more than 200 objects, ranging from a deer bone in which an arrowhead is embedded, and fossils such as petrified hyena droppings and mammoth molars, to a fragment of a skull of a young male Neanderthal. Studies of the forehead bone, dredged up in 2001 off the coast of Zeeland, suggests he was a big meat eater. A small cavity behind the brow bone is believed to be a scar from a harmless subcutaneous tumour that would have been visible as a lump above his eye.
But while the last decade has seen a growing number of expensive scientific studies, including a recent survey of the drowned landscape by the universities of Bradford and Ghent offering further clues to the cause of its destruction, it is the work of “citizen scientists” that has produced some of the most exciting artefacts, allowing a full story now to be told, according to Dr Sasja van der Vaart-Verschoof, assistant curator of the museum’s prehistory department... (MORE -details)
RELATED (History Guild): Doggerland: The Lost World Beneath the North Sea
The enigma of Europe's submerged behemoth
https://www.bbc.com/future/article/20210...ve-volcano
INTRO: When we think of Italy's volcanoes, we may assume that Etna, which overshadows Sicily, and Vesuvius, which famously destroyed Pompei, present the biggest danger to the peninsula's population and tourists. Yet there is another monster that could wreak havoc to the southern peninsula and its islands.
Its name is Marsili, and it is located around 175km (110 miles) south of Naples. With a height of 3,000m (9,800ft), and a base 70km long by 30km wide (43 by 19 miles), Marsili is a true giant. It is the largest active volcano in the whole of Europe. You won't ever see it, however, since its peak is 500m (1,640ft) under water, in the Tyrrhenian Sea.
Scientists have known of Marsili's existence for a century, but it is only within the last decade that they have started to investigate the dangers that Marsili might pose – and their findings are concerning. According to some recent models, its activity could potentially trigger an enormous tsunami, with a 30m-high (98ft) wave hitting Calabrian and Sicilian coasts.
Worse still, there would be next-to-no warning that the disaster was imminent – a fact that is leading some scientists to call for new technology to monitor the Mediterranean's movements.
An ancient menace. In terms of sheer size, Marsili cannot compete with Tamu Massif, beneath the north-west Pacific Ocean, which is around 4,460m (14,600ft) tall, and may house a complex of several separate volcanoes. Tamu Massif is extinct, however, whereas Marsili continues to rumble. It lies near the boundary of the Eurasian and African tectonic plates – movement that results in heightened geological activity.
It is just one of many volcanos in an arc off the south coast of Sicily and the east coast of southern Italy... (MORE)
Sea levels influence eruptions on volcanic island
https://www.brookes.ac.uk/about-brookes/...ic-island/
RELEASE: The rise and fall of sea levels influence the likelihood of volcanic eruptions on the Greek island of Santorini, new research led by Oxford Brookes University has discovered. Analysing the timings of eruptions over hundreds of thousands of years, the researchers found that a 40 metre fall in sea level is a crucial point beyond which eruptions are more likely to occur. The findings could have implications for millions of people living on volcanic islands around the world.
The research on the popular tourist destination was led by Dr Christopher Satow, Senior Lecturer in Physical Geography at Oxford Brookes. He says there are clues about past volcanic activity on Santorini in the layers of rock on the cliff face encircling the inner part of the island:
"A huge eruption 3,600 years ago caused the centre of what was then a conical island to sink into the sea, revealing an extraordinarily detailed history of over 200 volcanic eruptions preserved within the remaining circle of cliffs. Comparing this eruption history to a sea level record allowed us to show for the first time that the sea level has had an important role in determining the timing of eruptions at Santorini, and probably at many other island volcanoes around the world. The mechanism is quite simple: falling sea levels remove mass from the Earth's crust and the crust fractures as a result. These fractures allow magma to rise and feed eruptions at the surface."
The researchers say that eruptions at hundreds of other volcanic islands around the world may also have been influenced by fluctuations in sea level. Dr Satow added: "Just as when you pull a plug out of the bath, the water level drops everywhere throughout the bath at the same time; in a similar way, sea level changes occur at the same time everywhere across the globe."
Volcanic eruptions can change the climate, for example the eruption of the Philippines' Mt. Pinatubo in 1992 resulted in a fall in global temperature of 0.5oC.
But Dr Satow says the climate also impacts on volcanic activity: "What is less well known is that on long timescales, the climate can also affect volcanoes. As ice sheets retreated across volcanic landscapes after the last ice age, the removal of mass changed the stress conditions in the Earth's crust, allowing the fractures which feed volcanic eruptions to form more easily. As these ice sheets melted the global sea level rose rapidly, by around 100 meters, adding a significant mass to the crust around many volcanic islands which, in theory, should alter their eruptive activity."
Dr Satow concludes: "57% of the world's volcanoes are islands or are coastal, and are often home to large populations. Further vital research is needed to fully understand the effects of changing sea level on these volcanoes and the risks they pose to their populations."
Dr Satow collaborated with researchers from Royal Holloway University of London, Keele University, the University of Oxford, Uppsala University in Sweden, the University of Portsmouth and the University of Leicester. "Eruptive Activity of Santorini Volcano Controlled by Sea Level Rise and Fall" is published in Nature Geoscience. The research received funding from RCUK | Natural Environment Research Council (NERC) and Vetenskapsrådet (Swedish Research Council).
https://www.theguardian.com/science/2021...nt-secrets
INTRO: The idea of a “lost Atlantis” under the North Sea connecting Britain by land to continental Europe had been imagined by HG Wells in the late 19th century, with evidence of human inhabitation of the forgotten world following in 1931 when the trawler Colinda dredged up a lump of peat containing a spear point.
But it is only now, after a decade of pioneering research and the extraordinary finds of an army of amateur archaeologists scouring the Dutch coastline for artefacts and fossils, that a major exhibition is able to offer a window into Doggerland, a vast expanse of territory submerged following a tsunami 8,000 years ago, cutting the British Isles off from modern Belgium, the Netherlands and southern Scandinavia.
The exhibition, Doggerland: Lost World in the North Sea, at the Rijksmuseum van Oudheden (National Museum of Antiquities) in Leiden, southern Holland, includes more than 200 objects, ranging from a deer bone in which an arrowhead is embedded, and fossils such as petrified hyena droppings and mammoth molars, to a fragment of a skull of a young male Neanderthal. Studies of the forehead bone, dredged up in 2001 off the coast of Zeeland, suggests he was a big meat eater. A small cavity behind the brow bone is believed to be a scar from a harmless subcutaneous tumour that would have been visible as a lump above his eye.
But while the last decade has seen a growing number of expensive scientific studies, including a recent survey of the drowned landscape by the universities of Bradford and Ghent offering further clues to the cause of its destruction, it is the work of “citizen scientists” that has produced some of the most exciting artefacts, allowing a full story now to be told, according to Dr Sasja van der Vaart-Verschoof, assistant curator of the museum’s prehistory department... (MORE -details)
RELATED (History Guild): Doggerland: The Lost World Beneath the North Sea
The enigma of Europe's submerged behemoth
https://www.bbc.com/future/article/20210...ve-volcano
INTRO: When we think of Italy's volcanoes, we may assume that Etna, which overshadows Sicily, and Vesuvius, which famously destroyed Pompei, present the biggest danger to the peninsula's population and tourists. Yet there is another monster that could wreak havoc to the southern peninsula and its islands.
Its name is Marsili, and it is located around 175km (110 miles) south of Naples. With a height of 3,000m (9,800ft), and a base 70km long by 30km wide (43 by 19 miles), Marsili is a true giant. It is the largest active volcano in the whole of Europe. You won't ever see it, however, since its peak is 500m (1,640ft) under water, in the Tyrrhenian Sea.
Scientists have known of Marsili's existence for a century, but it is only within the last decade that they have started to investigate the dangers that Marsili might pose – and their findings are concerning. According to some recent models, its activity could potentially trigger an enormous tsunami, with a 30m-high (98ft) wave hitting Calabrian and Sicilian coasts.
Worse still, there would be next-to-no warning that the disaster was imminent – a fact that is leading some scientists to call for new technology to monitor the Mediterranean's movements.
An ancient menace. In terms of sheer size, Marsili cannot compete with Tamu Massif, beneath the north-west Pacific Ocean, which is around 4,460m (14,600ft) tall, and may house a complex of several separate volcanoes. Tamu Massif is extinct, however, whereas Marsili continues to rumble. It lies near the boundary of the Eurasian and African tectonic plates – movement that results in heightened geological activity.
It is just one of many volcanos in an arc off the south coast of Sicily and the east coast of southern Italy... (MORE)
Sea levels influence eruptions on volcanic island
https://www.brookes.ac.uk/about-brookes/...ic-island/
RELEASE: The rise and fall of sea levels influence the likelihood of volcanic eruptions on the Greek island of Santorini, new research led by Oxford Brookes University has discovered. Analysing the timings of eruptions over hundreds of thousands of years, the researchers found that a 40 metre fall in sea level is a crucial point beyond which eruptions are more likely to occur. The findings could have implications for millions of people living on volcanic islands around the world.
The research on the popular tourist destination was led by Dr Christopher Satow, Senior Lecturer in Physical Geography at Oxford Brookes. He says there are clues about past volcanic activity on Santorini in the layers of rock on the cliff face encircling the inner part of the island:
"A huge eruption 3,600 years ago caused the centre of what was then a conical island to sink into the sea, revealing an extraordinarily detailed history of over 200 volcanic eruptions preserved within the remaining circle of cliffs. Comparing this eruption history to a sea level record allowed us to show for the first time that the sea level has had an important role in determining the timing of eruptions at Santorini, and probably at many other island volcanoes around the world. The mechanism is quite simple: falling sea levels remove mass from the Earth's crust and the crust fractures as a result. These fractures allow magma to rise and feed eruptions at the surface."
The researchers say that eruptions at hundreds of other volcanic islands around the world may also have been influenced by fluctuations in sea level. Dr Satow added: "Just as when you pull a plug out of the bath, the water level drops everywhere throughout the bath at the same time; in a similar way, sea level changes occur at the same time everywhere across the globe."
Volcanic eruptions can change the climate, for example the eruption of the Philippines' Mt. Pinatubo in 1992 resulted in a fall in global temperature of 0.5oC.
But Dr Satow says the climate also impacts on volcanic activity: "What is less well known is that on long timescales, the climate can also affect volcanoes. As ice sheets retreated across volcanic landscapes after the last ice age, the removal of mass changed the stress conditions in the Earth's crust, allowing the fractures which feed volcanic eruptions to form more easily. As these ice sheets melted the global sea level rose rapidly, by around 100 meters, adding a significant mass to the crust around many volcanic islands which, in theory, should alter their eruptive activity."
Dr Satow concludes: "57% of the world's volcanoes are islands or are coastal, and are often home to large populations. Further vital research is needed to fully understand the effects of changing sea level on these volcanoes and the risks they pose to their populations."
Dr Satow collaborated with researchers from Royal Holloway University of London, Keele University, the University of Oxford, Uppsala University in Sweden, the University of Portsmouth and the University of Leicester. "Eruptive Activity of Santorini Volcano Controlled by Sea Level Rise and Fall" is published in Nature Geoscience. The research received funding from RCUK | Natural Environment Research Council (NERC) and Vetenskapsrådet (Swedish Research Council).