At the Greek city of Helike, on the shores of the Gulf of Corinth, 

 stood the great temple of Poseidon, god of the sea. According to 

 the historians of ancient Greece, more than 2300 years ago, when a 

 party of invading Achaeans dragged a group of suppliants from 

 the temple and slaughtered them, Poseidon was enraged by this 

 sacrilege and promised revenge. A few days later a terrible earth- 

 quake shook Helike. Buildings crashed and crumbled and, accord- 

 ing to one account, "the ground rose and fell Hke molehills come 

 up from the bowels of the earth." Two thousand feet up in the 

 mountains behind Helike, the city of Burra disappeared completely 

 into a chasm. During the evening of the same day, the sea withdrew 

 sUghtly, but when darkness fell surged forward with such violence 

 that, although Helike was a mile and a half inland, the waters poured 

 over it and covered the city to the tops of the trees. The destruction 

 was complete. By dawn of the next day there was not one inhabitant 

 of the city left alive. 



Sailors and fishermen from nearby, rowing over the ruins of the 

 submerged city, could look down on the trees and on the vast 

 bronze statue of Poseidon, still standing beneath the waves and 

 holding a sea horse in his upraised hand. For many years after the 

 disaster ferrymen rowed travelers over the sunken city, pointing 

 out its corroded, weed-covered walls, inch by inch disappearing 

 under layers of fine mud. Fishermen steered clear of the victorious 

 statue of Poseidon, knowing that he would surely tear their nets 

 if they ventured too close. Pliny, the Roman historian, dates the catas- 

 trophe at two years before Epaminondas' victory over the Spar- 

 tans at Leuctra. So it seems likely that the city of Helike was 

 destroyed in 373 b.c. 



The city now lies beneath twenty feet of water, and its streets 

 are covered by twenty feet of slime and mud. To excavate Helike's 

 priceless ruins is an underwater archaeologist's dream, but it would 

 be a project that would take many years of complex salvage work 

 and a huge amount of money. 



In many parts of the world, in all ages, there have been similar 

 tragedies; and with the help of geologists, the archaeologist can 

 determine their cause. Most changes in the elevation of coasts are 

 very slow, and have been less dramatic than the drowning of HeUke. 

 But in places where the change has been rapid, men have been 

 defenseless and have had to flee or die. Where the change has been 

 gradual — in Holland, for instance — great engineering works have 

 prolonged the life of coastal cities. Sometimes it has been simply a 

 matter of dredging channels in a shallowing harbor; other times of 

 raising the height of quays and sea walls to keep the water at bay, 

 as on the Thames estuary. Yet so great are the forces of the sea that 

 human efforts to hold it back have never been more than tempo- 

 rarily successful. 



The study of lost cities is inevitably linked with the study of 

 geology and oceanography. To begin with, we want to vmderstand 

 the reason for a given disaster. We know that there are several 

 ways the sea encroaches on the coasts. There may be an absolute 

 change in sea level - known as a eustatic change. This can be brought 

 on by a change in volume of the ocean basins, by excess melting or 

 freezing of the polar and continental icecaps, by a change in the 

 total quantity of water on the earth's surface, or by a change in the 

 temperature of the oceans. On the other hand, the coastal land 



A print of Lisbon being rocked by tlie earth- 

 qual<e of 1755. Dramatic ciianges in tlie 

 height of the land relative to the sea 

 can be brought about by violent earthquai^es. 



Details of the ocean floor and fissures are 

 shown near the submerged site of the Greek 

 city of Helike which sank into the sea 

 during an earthquake about 373 B.C. Today 

 Helike lies beneath more than forty feet 

 of water and mud. 



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