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May 15th, 2007, 02:01 PM
How Alexander the Great used 'Mother Nature'
By Roger Highfield, Science Editor
15/05/2007
Daily Telegraph
Lebanon
Alexander the Great had ''Mother Nature'' on his side when he conquered the island fortress of Tyre in 332 BC, says a study published today.
A bust of Alexander the Great
Tyre, in present day Lebanon, was then a strategic coastal base in the war between the Greeks and the Persians. Now archeologists have at last worked out how Alexander's engineers managed to build a causeway to enable his army to conquer what had become a bastion of resistance. All previous settlements on Alexander's journey from Macedonia had capitulated with little trouble.
The fact that Tyre was an island presented the Greek military commander with a serious headache: how was he to launch an effective attack?
Unable to storm the city, he had blockaded Tyre for seven months, but the defenders stood firm.
Archaeologists have known for some time that Alexander used the debris of the abandoned mainland city to build a causeway 3,000 yards long and up to 180 yards across. Once within reach of the city walls, he used siege engines to batter and finally breach the fortifications.
Over the centuries the silting up of a ‘sandbridge’ has turned the island of Tyre into an isthmus
But building a causeway in deep water would have meant raising the level of the sea floor considerably - an impossible feat in such a short space of time. However, researchers in France who analysed the coastal sediment record for the past 10,000 years have discovered how Alexander's engineers exploited a natural underwater "sandbridge".
The ''sandbridges'' are formed when sediment is deposited rapidly at a spot behind an island.
The findings, which are reported in the Proceedings of the National Academy of Science, show Alexander used "Mother Nature" to seize the island, said Dr Nick Marriner, of the Centre National de la Recherche Scientifique in Aix-en-provence, France. "Of course today engineers have a whole suite of tools available to them in construction, including steel, high-strength concrete and so on," he told The Daily Telegraph. "This was simply not the case during the Iron Age and engineers exploited Tyre's natural environment to serve as the foundations for the sea bridge.
''The causeway would have been built of timber - for which Phoenicia was renowned throughout the ancient world - stone and rubble." The team was able to work out how Tyre was first formed as an island, when sea levels rose around 8,000 years ago. After 6,000 BC, a slowing down of the rises in sea-level and the dissipation of wave energy by Tyre led to the natural growth of a spit of sediment linking the island to the coastline.
Over the centuries the causeway has silted up, transforming the island into an isthmus.
telegraph.co.uk
How Alexander the Great used 'Mother Nature'
By Roger Highfield, Science Editor
15/05/2007
Daily Telegraph
Lebanon
Alexander the Great had ''Mother Nature'' on his side when he conquered the island fortress of Tyre in 332 BC, says a study published today.
A bust of Alexander the Great
Tyre, in present day Lebanon, was then a strategic coastal base in the war between the Greeks and the Persians. Now archeologists have at last worked out how Alexander's engineers managed to build a causeway to enable his army to conquer what had become a bastion of resistance. All previous settlements on Alexander's journey from Macedonia had capitulated with little trouble.
The fact that Tyre was an island presented the Greek military commander with a serious headache: how was he to launch an effective attack?
Unable to storm the city, he had blockaded Tyre for seven months, but the defenders stood firm.
Archaeologists have known for some time that Alexander used the debris of the abandoned mainland city to build a causeway 3,000 yards long and up to 180 yards across. Once within reach of the city walls, he used siege engines to batter and finally breach the fortifications.
Over the centuries the silting up of a ‘sandbridge’ has turned the island of Tyre into an isthmus
But building a causeway in deep water would have meant raising the level of the sea floor considerably - an impossible feat in such a short space of time. However, researchers in France who analysed the coastal sediment record for the past 10,000 years have discovered how Alexander's engineers exploited a natural underwater "sandbridge".
The ''sandbridges'' are formed when sediment is deposited rapidly at a spot behind an island.
The findings, which are reported in the Proceedings of the National Academy of Science, show Alexander used "Mother Nature" to seize the island, said Dr Nick Marriner, of the Centre National de la Recherche Scientifique in Aix-en-provence, France. "Of course today engineers have a whole suite of tools available to them in construction, including steel, high-strength concrete and so on," he told The Daily Telegraph. "This was simply not the case during the Iron Age and engineers exploited Tyre's natural environment to serve as the foundations for the sea bridge.
''The causeway would have been built of timber - for which Phoenicia was renowned throughout the ancient world - stone and rubble." The team was able to work out how Tyre was first formed as an island, when sea levels rose around 8,000 years ago. After 6,000 BC, a slowing down of the rises in sea-level and the dissipation of wave energy by Tyre led to the natural growth of a spit of sediment linking the island to the coastline.
Over the centuries the causeway has silted up, transforming the island into an isthmus.
telegraph.co.uk
