Planet Knowledge

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Archaeologists Discover Three Roman shipwrecks

Archaeologists in Egypt have announced the discovery of three underwater shipwrecks that date from the Roman Era in Abu Qir Bay, Alexandria.

The three wrecks were uncovered during a research project in collaboration between the European Institute of Underwater Archaeology and the Supreme Council of Antiquities.

In a press statement, Dr. Mostafa Waziri added that the project also uncovered a Roman head carved in crystal that may belong to the commander of the Roman armies of “Antonio”, in addition to three gold coins dating back to the Emperor “Octavius”.

Dr. Osama Alnahas – Head of the Central Department of the Underwater Antiquities said that the initial excavations have also indicated that a fourth shipwreck remains to be unearthed, as the project discovered Large wooden planks, as well as archaeological remains of pottery vessels that may represent the ships hull and cargo.

Dr. Ayman Ashmawy, Head of the Ancient Egyptian Antiquities Sector said that the archaeological mission began its excavations last September.

Underwater research by both projects have included a survey of the soil in both the eastern port and the Abu Qir Bay, underwater excavations at the Heraklion sunken city in Abu Qir Bay which includes the discovery of a votive bark of the god Osiris,as well as the completion of the conservation and documentation works.

Geophysicists uncover new evidence for an alternative style of plate tectonics

When renowned University of Toronto (U of T) geophysicist J. Tuzo Wilson cemented concepts in the emerging field of plate tectonics in the 1960s, he revolutionized the study of Earth’s physical characteristics and behaviours.

Decades later, successor researchers at U of T and Istanbul Technical University have determined that a series of volcanoes and a mountain plateau across central Turkey formed not solely by the collision of tectonic plates, but instead by a massive drip and then detachment of the lower tectonic plate beneath Earth’s surface.

The researchers propose that the reason the Central Anatolian (Turkish) Plateau has risen by as much as one kilometre over the past 10 million years is because the planet’s crust and upper mantle – the lithosphere – has thickened and dripped below the region. As the lithosphere sank into the lower mantle, it first formed a basin at the surface, which later sprang up when the weight below broke off and sank further into the deeper depths of the mantle.

“It seems the heavy base of the tectonic plate has ‘dripped’ off into the mantle, leaving a massive gap in the plate beneath Central Anatolia. Essentially, by dropping this dense lithospheric anchor, there has been an upward bobbing of the entire land mass across hundreds of kilometres,” said Professor Oğuz H. Göğüş of the Eurasia Institute of Earth Sciences at Istanbul Technical University (ITU), lead author of a study reporting the findings published in Nature Communications this month.

Time slices of the computational geodynamic model showing dripping continental root and eventual surface uplift over a 4.5 million year period across Turkey’s Central Anatolian Plateau. CREDIT : University of Toronto handout

It’s a new idea where plate shortening initially squeezed and folded a mountain belt, triggering the thickening and dripping of the deep lithosphere, and then increasing the elevation of most of central Turkey. Puzzled by the presence of such a process at a significant distance away from regular plate tectonic boundaries, the research team set about identifying why, in an area of high heating and high elevation, is the lithosphere below completely gone – something that was recently discovered from seismology.

They tested high-performance computational models against known geological and geophysical observations of the Central Anatolian Plateau, and demonstrated that a drip of lithospheric material below the surface can account for the measured elevation changes across the region.

“It’s a new variation on the fundamental concepts of plate tectonics,” said Professor Russell Pysklywec, chair of the Department of Earth Sciences at U of T and one of the study’s coauthors. “It gives us some insight into the connection between the slow circulation of near-solid rock in Earth’s mantle caused by convection currents carrying heat upwards from the planet’s interior, and observed active plate tectonics at the surface.

“This is part of the holy grail of plate tectonics – linking the two processes to understand how the crust responds to the mantle thermal engine of the planet.”

Pysklywec carried out the study with Göğüş, who received his PhD from U of T in 2010, and fellow researchers at ITU including Professor A. M. C. Şengör, and Erkan Gün of the Eurasia Institute of Earth Sciences at Istanbul Technical Institute. Gün is also now a current graduate student at U of T, supervised by Pysklywec. The research adds to decades of groundbreaking work in plate tectonics at U of T, and builds on Wilson’s seminal work.

“Tuzo Wilson is a towering figure in geophysics internationally and the person most responsible for pioneering the ideas of plate tectonics in the 1960s,” said Pysklywec. “I am pleased that we are continuing his legacy in geophysics with our work.”

While Pysklywec notes there are many locations on Earth missing its lithosphere below, he is quick to reassure that no place is in imminent danger of sinking into the mantle or boosting upwards overnight. “Our results show that the Central Anatolian Plateau rose over a period of millions of years. We’re talking about mantle fluid motions and uplift at the pace at which fingernails grow.”

Göğüş highlights the links of the tectonics with human history saying, “The findings are exciting also because of the link with the remarkable historical human activity of Central Anatolia where some of the earliest known civilizations have existed. For example, Central Anatolia is described as an elevated, dry, cold plain of Lycaonia in Strabo’s Geographika in 7 BC, and even cave paintings in the region dating to approximately 7000 BC record active volcanic eruptions on the plateau.”

UNIVERSITY OF TORONTO

Versailles Stories – Fountains and Fireworks

During the summer months, the gardens of Versailles come alive to the sound of seventeenth-century music and the play of the fountains. Visitors are encouraged to walk through the groves of Versailles where every fountain is happily spouting crystal clear water. Gabriel Novello and his team spend weeks preparing and fine-tuning the fountains for the spectacle, working in tunnels which stretch right the way under the world-famous palace gardens.


Episode Length: 00:28:00

Year: 2009

Episode: 3


 

Versailles Stories – Follow the Guide

The programme follows the specialist guides who bring Versailles to life for the thousands of people who visit each year. Fabrice Callet has long dreamed of becoming a guide at Versailles. Will he make the grade to become a privileged key holder to the palace doors?


Episode Length: 00:28:00

Year: 2009

Episode: 2


 

Versailles Stories – Putting on a Show

Every year, over five dates in July and August, members of the public flock to Versailles for the firework display, music and lightshow that is famous throughout the world. Music, performances and fireworks play together to create a magnificent spectacle. We follow Bartabas and his team of expert horse-riders as they rehearse and prepare the event they feel sure will propel them into the international spotlight as a must-see part of the Versailles experience.


Episode Length: 00:28:00

Year: 2009

Episode: 1


 

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