Earthquakes may have destroyed Mycenae

The grand Mycenaens, the first Greeks, inspired the legends of the Trojan Wars, "The Iliad" and "The Odyssey." Their culture abruptly declined around 1200 B.C., marking the start of a Dark Ages in Greece.

Aerial view of Mycenae [Credit: TANN]

The disappearance of the Mycenaens is a Mediterranean mystery. Leading explanations include warfare with invaders or uprising by lower classes. Some scientists also think one of the country's frequent earthquakes could have contributed to the culture's collapse. At the ruins of Tiryns, a fortified palace, geologists hope to find evidence to confirm whether an earthquake was a likely culprit.

Tiryns was one of the great Mycenaean cities. Atop a limestone hill, the city-state's king built a palace with walls so thick they were called Cyclopean, because only the one-eyed monster could have carried the massive limestone blocks. The walls were about 30 feet (10 meters) high and 26 feet (8 m) wide, with blocks weighing 13 tons, said Klaus-G. Hinzen, a seismologist at the University of Cologne in Germany and project leader. He presented his team's preliminary results April 19 at the Seismological Society of America's annual meeting in Salt Lake City.

Hinzen and his colleagues have created a 3D model of Tiryns based on laser scans of the remaining structures. Their goal is to determine if the walls' collapse could only have been caused by an earthquake. Geophysical scanning of the sediment and rock layers beneath the surface will provide information for engineering studies on how the ground would shake in a temblor.

The work is complex, because many blocks were moved by amateur archaeologist Heinrich Schliemann in 1884 and later 20th-century restorations, Hinzen said. By combing through historic photos, the team found unaltered wall sections to test. They also hope to use a technique called optical luminescence dating on soil under the blocks, which could reveal whether the walls toppled all at the same time, as during an earthquake.

"This is really a challenge because of the alterations. We want to take a careful look at the original conditions," Hinzen told OurAmazingPlanet.

Another hurdle: finding the killer quake. There are no written records from the Mycenaean decline that describe a major earthquake, nor oral folklore. Hinzen also said compared with other areas of Greece, the region has relatively few active faults nearby. "There is no evidence for an earthquake at this time, but there was strong activity at the subduction zone nearby," he said.

The Mycenaean preference to place their fortresses atop limestone hills surrounded by sediment would concentrate shaking, even from distant earthquakes, Hinzen said. "The [seismic] waves get trapped in the outcrop and this can do a lot of damage. They are on very vulnerable sites," he said.

The researchers also plan to study the ancient Mycenaean city of Midea. The group has done similar work investigating ancient earthquakes in Turkey, Germany and Rome.

Author: Becky Oskin | Source: OurAmazingPlanet [April 23, 2013]

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