National Geographic : 1924 Apr
SAKURAJIMA, JAPAN'S GREATEST VOLCANIC ERUPTION A Convulsion of Nature Whose Ravages Were Minimized by Scientific Knowledge, Compared with the Terrors and Destruction of the Recent Tokyo Earthquake BY T. A. JAGGAR Director, Hawaiian Volcano Observatory T WO of the greatest convulsions of the earth's surface in the his tory of mankind have occurred in Japan during the present generation. The earthquake of last September de stroyed 400,000 lives and wiped out bil lions of dollars' worth of property; the Sakurajima volcanic eruption of 1914 (the greatest in the annals of the Island lEmpire) resulted in the loss of only 35 lives and some millions of dollars in property. Scientific investigation is, in large measure, to be credited with the relatively few casualties in the latter instance, for it was through the prediction of the im minence of the Sakurajima outbreak that the inhabitants of a populous district were enabled to flee from the wrath about to come. In Tokyo, on the other hand, the cataclysm of earthquake and succeeding flames caught the great Japanese metrop olis of two million people and its adjacent seaport unawares and unprepared. It was through a study of premonitory earthquakes in their relation to volcanic outbreaks that the Sakurajima eruption was definitely predicted; conversely, it is hoped that, in time, through exhaustive study of volcanic activities, earthquakes may be predicted with accuracy. If such forecasting can be achieved, it is conceiv alle that an earthquake of the severity of the Tokyo disturbance could occur with a loss of life and property almost negli gible in comparison with what actually happened in September, 1923. The phenomena of the Sakurajima eruption, therefore, are proving of tran scendent importance to the scientific world, and the measures which were taken to safeguard life at that time are being eagerly studied anew. The volcano of Sakurajima, shaped much like Vesuvius, rises to a height of 3,506 feet, directly opposite the city of Kagoshima, in Kagoshima Bay-a tongue of water extending some fifty miles into the southern end of Kyushu, the most southerly of the four main islands of the Japanese Archipelago (see page 449). Growths of young pine trees mark the course of old lava flows from the two main craters of the summit. KAGOSIIIMA'S FATI FORESEEN BY SCIliNTISTS Prior to the eruption of 1914, eighteen villages, with an aggregate population of 22,000 industrious farmers and fisher folk, nestled on the shores of this small volcanic island, which nearly filled the bay between Kagoshima and the (sumi promontory. The channel between the volcano and the city was barely two and one-half miles wide, with a depth of from nineteen to seventy fathoms, while that on the Osumi side was only one-third of a mile wide, with an average depth of more than fifty fathoms. Kagoshima, the thriving capital city of the province, with a population of 70,000. is the center of Satsuma pottery manu facture and of a fertile farming region, producing tobacco, citrus fruit, and sugar cane (see pages 450, 451, and 454). Men of science had long known what lay in store for Kagoshima. Experience had taught observers that when "swarms" of earthquakes begin in the vicinity of an active volcano, the underground dragon is writhing and preparing to make trouble.