A writer in a late number of CJiambers' Journal, under the 1 caption, "The Usefulness of Earthquakes," attempts the theory that these phenomena, combined with volcanic eruptions, are the means of repairing the waste made by the action of the, .sea on shores and of rainfall on interiors. He assumes that " If the solid substance of the earth formed a perfect sph ere in ante-geologic times—that is in ages preceding those to which our present geologic studies extend—there can be no doubt that there was theiAo visible land above the surface of the water ; the ocean must, have formed a uniformly dee,p covering to the submerged surface of the solid globe. In this state of things, nothing but the earth's subterranean forces should tend to the production of continents and islands." The if which we have italicized is the best reply to his doubttul assumption; there is no evidence that the earth, was ever a perfect sphere ; in fact, not only astronomy but geology witnesses the contrary. The earth is an oblate spheroid, and, so far as our means of ascertaining extends, was always of this form. If the earth was ever, for any geologic period, submerged with water, some evidences would have remained in every portion of its surface. By a " geologic period," we mean the duration of time between one great natural condition, as determined by geologists, and its successor; periods counted by a lapse of time compared to which our historical period is as the dust in the balance. Any one who caref ully reads the records of geological investigation will see that the probabilities are strongly in favor of a condition of the earth's surface as regards protuberances and depressions—mountains and valleys, elevated plateaus and depressed plains, land and water—in ancient times very similar to that which now exists. To be sure, it is evident that portions, now dry land, formed once the bottom of seas, and mountains were but islands, but there is no reason for doubting that the present seas might have been dry land ; our means for determining this fact, however, are meager compared with those afforded for an examination of dry land. We cannot traverse the ocean's bottom as we can the valleys of the habitable earth. It may be possible that a larger proportion of the earth's surface was once covered by water than at present; but while this opinion may be entertained, it is morally certain that where seas now roll their unobstructed waves dry land in many instances existed. Why could not the peninsula of Yucatan with Cuba, ; Hayti, Jamaica, and the group of Caribbean islands once have inclosed as an inland lake what is known now as the Caribbean Sea ? And why not the peninsulas of Florida and Yucatan with western Cuba have similarly inclosed the Gulf of Mexico ? So at the Straits of Dover, there is evidence, from recent soundings and examinations, that England and Prance wore once physically united as they subsequently were politically. The writer makes this statement: " At first sight it may ' seem paradoxical to assert that earthquakes, fearfully destruc- j tive as they have so often proved, are yet essentially preservative and restorative phenomena; yet this is strictly the case. Had no earthquakes taken place in old times, man would not now be living on the face of the earth ; if no earthquakes were to take place in future, the term of man's existence wouH be limited within a range of time far less than that to which it seems likely, in all human probability, to be extended." This does seem paradoxical, because, for every case of the permanent upheaval of barren rock by earthquakes there can be brought the record of permanent disappearance of fertile lands. Indeed, the destruction caused by earthquakes in the sinking or ingulfing of tracts of land and producing in their i place lakes of noxious waters, or allowing the inroads of the I sea has been so great and so much more frequent than the gift of solid land, that earthquakes are, the world over, and ' in all times, regarded with dread as the most destructive agent in nature. Prom the time that (as the " New England Primer," published in 1770, has it), Proud Koran's troop Was swallowed up, down to the recent destruction of Arequipa and other cities on the western coast of South America, the earthquake has been a destroyer and not a restorer. Prom the disappearance of the island, Atlantis, mentioned by Plato in his Timceus to the recent reports of similar disappearances, the earthquake has diminished rather than increased the amount of habitable land.
This article was originally published with the title "Land and Water—Are Earthquakes Land Makers?"