Mary Williams, age 12, of Peoria, Illinois, for her question:
Is it true that islands appear and disappear?
Our home planet has never been a dull place. The lofty mountains seem eternal. The routines of the sea appear to be changeless. But the surface of the earth has an age old history of restless events. Its seas change, its mountains rise and fall, its islands appear and disappear.
The Greek philosopher, Plato, was a reliable reporter and his writings include detail accounts of an ancient island that sank beneath the sea. For 2,000 years, this report has been handed down as the fabulous story of Atlantis. Over the years, many experts sought to prove that the story was true that an immense island kingdom beyond Gibraltar had disappeared below the Atlantic in the remote past. But no evidence was found and the world of science regarded Atlantis as a fanciful legend. That is, until recently. Now many geologists are not so sure.
Someone took a new look at the old report and rechecked the still older figures upon which Plato had based it. The researcher suspected that Plato had misread those older figures by a factor of 10. Being a modern marine geologist, he went probing for a smaller` island, much closer to Greece, one that could have disappeared about 3,500 years ago. Andtbe found it. His team of experts explored the tiny Aegean island of Thera, the surrounding seabed and other nearby isles. This region of the earth's crust indeed had once been a major island. And most of the land had sunk below the sea about 3,500 years ago.
On Thera, archeologists have begun to unearth a superb city, buried under 2,500 feet of volcanic debris. It could, they suspect, be the ruins of Atlantis. If so, the fabulous realm was much smaller and less ancient. In any case, we have scientific proof that in 1490 B.C., 75 miles north of Crete, most of a large island was destroyed by volcanic upheaval and disappeared under the sea.
The tale of Atlantis may be true, but in any case it is ancient history. We know for sure that countless other islands have appeared and disappeared through the ages, right up to the present time. In 1963, fishermen off the coast of Iceland were tossed and shaken by a steamy volcanic eruption on the floor of. the sea. In a few months, the submarine volcano piled a cone of cinders 500 feet above sea level. Lava flows continued, adding an acre of islands appear and disappear
The fiery young island was named Surtsey. When the lava flows ceased about 18 months later, Surtsey had almost a square mile of dry land. Then the submarine upheaval began to build a new cone of debris a short distance away. A cindery island of 35 acres reached above the water and then the underwater volcano became quiet. The pounding seas bashed and eroded this cindery new isle and soon it disappeared beneath the waves. But nearby Surtsey still stands and this sturdy new island is expected to remain on the map.
Geologists have countless records of appearing and disappearing islands. Some are sudden and dramatic events caused by volcanoes. On the other hand, great rivers build islands with gentle patience in their flat, muddy deltas. Sometimes the sea cuts off a peninsula and the separated finger of dry land becomes an island surrounded by water. The .land and the sea have been warring for territory since the earth began. And the appearance and disappearance of islands are common events of the age old geological battle front.