THE UNSTABLE EARTH.

Wairarapa Age, Volume XXXII, Issue 3101, 26 January 1909, Page 4

THE UNSTABLE EARTH.

The cause of the Messina earthquake, says a writer in the "Sydney Morning Herald." is perhaps better known than that of any other. That part of Italy has been moving more or less continuously for three years, and moved at frequent intervals before that. Parallel to the Italian coast, somewhere in the line from Vesuvius to Etna, and curving round to Sicily there is said to be a fault in the earth's surface. The earthquake was the shifting up or down, of one side or the other of this long crack. There are forces that play with the surface of the earth as a man might handle an india-rubber ball, and occasionally the earth cracks, as the ball may do, and nearly always in a curved line. As to what these forces are there is a good deal of dispute. The surface of the earth is continually grating up and down. Professor Milne estimates that soma 30,000 small earthquakes took place every year. "If we had records we might readily estimate the time ;when this activity woul 1 cease. When this ceases surface denundation will be unopposed. Bit by bit ; land areas will be reduced to sea level, and the habitable surfaces, as we now see them, will be no more."' The noise heard when an earthquaKe takes place is attributed to the grating of two edges of the fault near the surface. Along some of the earthquake flaws in the world's surface, there is a continual regular movement, corresponding with night and day, or the tides, supposed to be caused by the extra weight of air and water which is above one side of the flaw at one tim«, and absent during the other. Professor Milne has mady the astonishing discovery that at ordinary times the surface of the earth moves. Two valleys in the Isle of Wight, in which he conducted investigations, were found to behave like flowers, opening when the sun was shining, and closing at night.; that is to say, the heights were closer to each other during the night during the day. Professor Milne puts this down to the collec- ■ tion in the valley bed at night of ; an immense weight of water sucked in by vegetation. Apparently the stability ot the earth, which is the [ ultimate basis of our daily lives, is , not absolute.