Thursday, March 31, 2011

1868 Earthquakes and Tidal Waves Affect California

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Earthquakes and Tidal Waves - December 5, 1868

Later and fuller details are every day increasing the interest with which scientific observers regard the recent earthquakes and tidal disturbances, and confirming our first impression that these convulsions of nature would prove to be among the most remarkable and extensive of which there is any written record. They have been experienced at short intervals during the last three months, and there is no reason to suppose that we have yet felt the last of them, the latest having been reported only a week ago.

The shocks have followed no particular direction, and been confined to no particular quarter of the earth. Beginning in the middle of the Pacific Ocean, they seem to have affected all its eastern shores and its southern and western islands, and, skipping the whole breadth of the North American Continent and the Atlantic Ocean, to have broken out in Ireland.

We may yet learn that the remoter countries of Asia have likewise been shaken. The first of this great series of convulsions, so far as our intelligence now extends, occurred, in the Sandwich Islands, eleven days before the terrible disaster in Peru. Violent shocks were felt in different parts of the groups from the 2d to the 9th of August, accompanied with heavy storms of thunder and lightning. The western coast of South America was devastated by awful earthquakes from the 13th to the 15th of August, and at the same time the shocks were felt again in the Sandwich Islands, though less severely than before.

On the 17th there were shocks in New Zealand. About the middle of September shocks were felt by vessels in the Eastern Pacific. On or about the 1st of October, they were experienced again in the Sandwich Islands. In California they wee felt from the 21st to the 25th, with considerable severity, and were repeated slightly up to the 6th of November. On the 23d of October we hear of earthquakes in Ireland. On the 4th of November there was one at Vancouver Island.

The tidal waves which have accompanied all the most serious of these convulsions are peculiarly interesting subjects of study. It has been remarked, as an evidence of the rapidity with which they travel, that they reached the California coast as early as the morning of the 14th of August, having moved over a distance of 4,000 miles in a little more than 14 hours; but it now appears that their speed is even greater than this, for they were felt in the Sandwich Islands, nearly an equal distance, on the evening of the 13th, only four hours after the earthquake in Peru, lasting through the night, and obtaining their greatest force the nest morning, almost simultaneously with their appearance on the opposite California coast. This would give them a velocity of about a thousand miles an hour. They seem, however, not to have been driven in more than one direction at a time. The Sandwich Islands lie north west of the place of disturbance in Peru. Toward the west and southwest, we have no record of tidal phenomena earlier than the 15th of August, when the waters of Japan and Australia were simultaneously agitated in the same manner.

These waves may have been either propagated by fresh convulsions on the South American coast, or revulsions from the disturbances at the Sandwich Islands. We have no sufficient data as yet determining in what direction the waves traveled, or what was their size or their velocity. We trust that the attention of competent observers may have been drawn to these points; for by means of them it would be possible to determine the depth of the Pacific Ocean, the size and velocity of waves bearing, as is well known, a fixed ratio to the depth of the water.

A great tidal wave fell upon Hawaii, one of the Sandwich Islands, on the 15th of October, destroying a great many houses and other property. Accepting the generally received theory that these phenomena are caused by earthquakes , we may expect intelligence of another great calamity about that date in some country bordering on the Pacific from which we have yet received no advices. But the disturbance may have arisen in the bed of the ocean, in which case, unless a stray sailing vessel chanced to be within reach of it, no account of the phenomenon may ever come to us.

New York Tribune, November 17, 1868.
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