Scandinavia is of still further special interest because very appreciable earth movements have there come under human observation. Marks carefully placed along the shores of Sweden by the government have proved that during the last 150 years the southern end of the country has actually subsided several feet, while from Stockholm north the land has risen in increasing amount, reaching a maximum of seven or eight feet. In southern Sweden, at Malmo, a certain street now at times becomes covered by wind-driven high water, and during excavations made some years ago an older street eight feet below the present one was found.
A theory which appears to be in perfect harmony with the facts to account for the subsidence and partial reelevation of central eastern North America and Scandinavia since the beginning of the Ice Age is that the great weight of ice during the Ice Age pressed the land down, and that since the removal of the ice there has been an appreciable tendency for the land to spring back.
Certain crustal movements which have occurred about the Bay of Naples are of very special interest because actual human history dates can be placed upon them. Most remarkable are the records in connection with the temple of Jupiter Serapis which was built near the shore before the Christian era. The land sank about five feet and a new pavement had to be constructed; then, by the middle of the third century A. D., the temple rose to well above sea level. By about the ninth century the land had subsided fully thirty feet, so that marble columns of the temple were bored full of holes as high as twenty-one feet above their bases by marine-shelled animals, species of which still live in the bay. Then a slow uplift of twenty-three feet began, bringing the bases of the columns two feet above sea level by 1749. Since that time a slight sinking has taken place and this seems to be still going on. Three of the marble columns with the borings still stand in upright position.
While the movements just described were taking place, the island of Capri, twenty miles across the Bay of Naples, has slowly sunk to an amount estimated at thirty or forty feet as proved by evidence from the famous Blue Grotto. About the beginning of the Christian era a large ancient wave-cut cave, part of which is now called the Blue Grotto, had its floor above sea level, and it was used by certain Romans as a cool place to retire to from the heat. In order to obtain better light an opening was cut through its upper portion. The land has sunk so much that at the present time even part of the artificial opening (through which tourists pass) is now under water.