EXPERTS DIFFER.

Taranaki Daily News, 16 January 1918, Page 7

EXPERTS DIFFER.

SUN-STORMS AND EARTHQUAKES. THE GOVERNMENT SEISMOLOGIST ,ON THE SUBJECT. The attention of the Government Seismologists of every school of thought in been called to certain statements made bv Mr. Clement Wragge in au interview with a reporter of the New Zealand Herald, Mr. Hogben remarks as follows: The possibility of the influence of the sun and moon or of Meteorological changes as factors in causing earthquakes has been fully discussed by seismologists of every school of thought in many countries. After the most careful examination of all the records (including those of many thousands of earthquakes), they have come to the conclusion, practically, that if any of the tilings referred to have any weight at all (which many regard as very doubtful) that weight is extremely small; this applies even to differences of tidal attraction and of barometric pressure. In particular, as regard the variation in the amount of heat received from the- sun in different years and seasons, Professor C. G. Knott sums up the case thus: "It is httrdlv possible to credit the solar radiation with any direct influence; for, as we learnt long ago from the measurements by Forbes of underground temperature, solar radiation penetrates a very shorib distance into th« earth's crust." (Physics of Earthquake Phenomena, p. 129). I may observe that the earth movements giving rise to seismic vibrations generally take place at" a depth of from 15 to 25 miles below the surface, far beyond the reach of any changes in surface temperature. It would be very misleading to attempt to draw any conclusions or make predictions from the coincidences of particular earthquakes with solar events. The number of earthquakes recorded every year is very large—about 15,000 so that, if I were to prophesy an earthquake somewhere on anv nj.y whatf'U' I taken at random, th? chance wouidjibe about forty to oiie that I should ba right. Even the number of large earthquakes in any year is not'small, so that coincide ences would be bound to appear; and, if we took a few of these as substantial arguments, we could prove almost any theory of the cause of earthquake: The Wairarapa earthquake of August 6, 1917, proceeded from an origin to the east-south-east, beneath the Pacific Ocean; there have been many shocks from the same region (probably a band of parallel fault-planes), recorded during the last fifty or sixty years, including the shock of February 17, 1863, and that of August 9, 1904, and at least twenty during the last four or five years. As'the nearest part of the disturbed region is about 200 miles' from the New Zealand coast, even nervous people may sleep nuictly in their neds, without fear of any serious damage fro.m this the most important probably of the seismic origins in or near Now Zealand. I find myself unable to attach any scientific meaning to the picturesque statement that 'in consequence of the change of wireless wave lengths from the sun—Jilce altering the gear of a motor-car—which are bound to operate after 1920, conditions will become more favorable for seismic and volcanic action,'' and so on.