The Geological Society conference on volcanoes, earthquakes and archaeology
THE RISE and fall of many ancient societies may have been due to earthquakes, according to a Stanford University researcher.
Amos Nur says that new and revised evidence shows that earthquakes could have caused Jericho's walls to tumble down and many other cataclysms and social upheavals in the ancient world.
Dr Nur, who spoke at The Geological Society conference on Volcanoes, Earthquakes and Archaeology on Monday, links the episodic nature of earthquake activity to historical events.
The geophysics scholar says that certain quake-prone areas go through periods of greater or lesser activity. These crises can last for relatively short periods, perhaps a few decades, and are interspersed by long periods of inactivity.
He pinpoints the seismic crisis of the eastern Mediterranean during the second half of the fourth century ad. In this century, the north Anatolian fault, running through northern Turkey, has caused clusters of earthquakes.
Ancient societies would be ill-prepared, by modern standards, to withstand intense earthquakes, and associated tidal waves. Even a single earthquake could wipe out economic, social and political structures.
Dr Nur says that because elites controlled ancient societies they were particularly vulnerable to natural disasters.
The rulers tended to live in fortified cities, meaning that many would be killed by debris during an earthquake compared with poorer rural populations. Their defences would also be breached and so they would be particularly vulnerable if at war. In short, societies could disappear very rapidly.
The destruction of one elite would lead to the collapse of economic and social structures, creating a power vacuum. This vacuum could provide the impetus for invaders or poorer, perhaps indigenous, people to fill the gap.
However, such changes would occur slowly and Dr Nur says that if a devastating earthquake coincided with a major war then societies could be plunged into a dark ages period, possibly lasting hundreds of years.
He said: "During a regional seismic crisis an entire region must have been subjected to a series of devastations by earthquakes over a short period of time. The catastrophic collapse of the main eastern Mediterranean civilisations at the end of the Bronze Age may be a case in point." Sparta's rise and fall may be another example. The uprising of the Helot serfs in the fifth century bc came amid long periods of war. Dr Nur speculates that the demise of Spartan power may have been caused, in part, by earthquake activity at the time.
But perhaps the most obvious example of earthquake activity, at least for a non-believer, is the fall of Jericho, sometime between 1400bc and 1250bc.
The Bible suggests that divine intervention and rams' horns were responsible for Joshua's spectacular victory. Dr Nur points out that Jericho stands on a fault line close to the point where the African continental plate meets the Asian plate. It had been destroyed and rebuilt many times.
Dr Nur believes that the fabric of society remains vulnerable to earthquakes. Damage to the Japanese city of Kobe in 1995, following a quake registering 7.2 on the Richter scale, cost about $150 billion. If Tokyo was hit, as it was in 1923, by a similar or larger earthquake, the ramifications for global finance could be enormous.