Ralph Stockman Tarr

In the summer of 1905, a party of geologists sent by the United States Geological Survey visited Yakutat Bay.

The party was under the direction of the late Professor Ralph S. Tarr with Mr. Lawrence Martin as physiographic assistant.

very early in their work they noticed dead mussels and barnacles adhering to the cliff far above the reach of the present tides had the barnacles died many years ago they would have lost their hold on the rock and indeed many of them had fallen on to the ledges below it was therefore evident that quite recently there must have been a considerable rise of the land and the observers at once and as it proved rightly attributed the work of elevation to the crustal movements which had caused the earthquakes of eighteen ninety nine in nineteen o six professor tarr again visited the district intending to study the glaciers farther to the west but was unable to cross them owing to their great advance and the unusually crevassed condition of their surfaces further observations on the effects of the earthquake on the glaciers were made by messrs tarr and martin in nineteen o nine and again in the following year by mr martin The very valuable report on the earthquake and its effects by these two capable observers has recently been published by the Geological Survey of the United States.

The Earthquakes of Yakutat Bay, Alaska, in September 1899, by R.S. Tarr and L. Martin, U.S. Geological Survey, Professional Paper 69. as the report however is lengthy and somewhat inaccessible to english readers i propose in this article to give a summary of the principal facts observed devoting special attention to those features which distinguish the earthquake from most others with which we are acquainted these are one the remarkable changes of level manifested in yakutat bay the maximum uplift amounting to more than forty seven feet and two the advance and crevassing of the glaciers which took place principally between the years nineteen o five and nineteen ten and which may not yet have come to an end the earthquake disturbed the southern part of alaska and especially that district in which the average trend of the coast is nearly east and west the region surrounding yakutat bay was that in which the severest shaking and the changes of level were manifested the disturbed area on land contains two hundred and sixteen thousand three hundred square miles but this can only be about half the total disturbed area which must therefore be estimated at about four hundred and thirty two thousand square miles but even this amount great as it is must be too small for the earthquake was felt at two isolated places to the west which are respectively six hundred and seventy and seven hundred and thirty miles from yakutat bay thus if the boundary of the disturbed area be regarded as a circle with a radius of seven hundred miles the total area shaken by the earthquake must amount to about one and a half million square miles this figure alone gives us some conception of the violence of the earthquake it has seldom been exceeded by any known disturbance the great lisbon earthquake of seventeen fifty five disturbed an area of not more than about two million square miles the assam earthquake of eighteen ninety seven one of about one and three quarter million square miles the kangra india earthquake of nineteen o five one of about one and one half million square miles the largest known disturbed area is that of the charleston earthquake of eighteen eighty six which must have shaken more than two and three quarter million square miles this earthquake however was not one of exceptional strength it merely owes its extensive area of perception to the presence of a sensitive and intelligent population on the other hand the great japanese earthquake of eighteen ninety one disturbed only three hundred and thirty thousand square miles the californian earthquake of nineteen o six about three hundred and seventy thousand square miles and the messina earthquake of nineteen o eight about two hundred thousand square miles thus the alaskan earthquake of eighteen ninety nine must be ranked among the greatest of all recorded earthquakes this great earthquake however was not the earliest of the series so far as known the first earthquake occurred on september third at three thirty p m local time or september fourth at twelve twenty two a m greenwich mean time it was strong enough to be recorded in the seismological observatories of europe and other distant places there is some uncertainty as to the seat of this earthquake but as the coast is said to have been uplifted at yakutka one hundred miles west of yakutat it is possible that the central region was in the neighborhood of that place during the next week about fifty slight shocks were noticed near yakutat bay then on september tenth came two great earthquakes one about eight a m local time the other and greatest of all at twelve twenty two p m local time or nine forty p m greenwich mean time on the same day about fifty slighter shocks were observed both of the great shocks originated in and near yakutat bay but it is probable that the uplift of the coast occurred with the latter of the two as the earlier one was not accompanied by any sea wave Severe shocks also occurred on September 15th, 17th, 23rd, 26th, and 29th, intercalated among a large number of minor shakings to which little attention was naturally paid by the inhabitants of the district.

In the summer of 1905, a party of geologists sent by the United States Geological Survey visited Yakutat Bay.

The party was under the direction of the late Professor Ralph S. Tarr, with Mr. Lawrence Martin as physiographic assistant.

Very early in their work they noticed dead mussels and barnacles adhering to the cliff, far above the reach of the present tides.

Had the barnacles died many years ago, they would have lost their hold on the rock, and indeed many of them had fallen onto the ledges below.

In the summer of 1905, a party of geologists sent by the United States Geological Survey visited Yakutat Bay.

The party was under the direction of the late Professor Ralph S. Tarr with Mr. Lawrence Martin as physiographic assistant.

very early in their work they noticed dead mussels and barnacles adhering to the cliff far above the reach of the present tides had the barnacles died many years ago they would have lost their hold on the rock and indeed many of them had fallen on to the ledges below it was therefore evident that quite recently there must have been a considerable rise of the land and the observers at once and as it proved rightly attributed the work of elevation to the crustal movements which had caused the earthquakes of eighteen ninety nine in nineteen o six professor tarr again visited the district intending to study the glaciers farther to the west but was unable to cross them owing to their great advance and the unusually crevassed condition of their surfaces further observations on the effects of the earthquake on the glaciers were made by messrs tarr and martin in nineteen o nine and again in the following year by mr martin The very valuable report on the earthquake and its effects by these two capable observers has recently been published by the Geological Survey of the United States.

The Earthquakes of Yakutat Bay, Alaska, in September 1899, by R.S. Tarr and L. Martin, U.S. Geological Survey, Professional Paper 69. as the report however is lengthy and somewhat inaccessible to english readers i propose in this article to give a summary of the principal facts observed devoting special attention to those features which distinguish the earthquake from most others with which we are acquainted these are one the remarkable changes of level manifested in yakutat bay the maximum uplift amounting to more than forty seven feet and two the advance and crevassing of the glaciers which took place principally between the years nineteen o five and nineteen ten and which may not yet have come to an end the earthquake disturbed the southern part of alaska and especially that district in which the average trend of the coast is nearly east and west the region surrounding yakutat bay was that in which the severest shaking and the changes of level were manifested the disturbed area on land contains two hundred and sixteen thousand three hundred square miles but this can only be about half the total disturbed area which must therefore be estimated at about four hundred and thirty two thousand square miles but even this amount great as it is must be too small for the earthquake was felt at two isolated places to the west which are respectively six hundred and seventy and seven hundred and thirty miles from yakutat bay thus if the boundary of the disturbed area be regarded as a circle with a radius of seven hundred miles the total area shaken by the earthquake must amount to about one and a half million square miles this figure alone gives us some conception of the violence of the earthquake it has seldom been exceeded by any known disturbance the great lisbon earthquake of seventeen fifty five disturbed an area of not more than about two million square miles the assam earthquake of eighteen ninety seven one of about one and three quarter million square miles the kangra india earthquake of nineteen o five one of about one and one half million square miles the largest known disturbed area is that of the charleston earthquake of eighteen eighty six which must have shaken more than two and three quarter million square miles this earthquake however was not one of exceptional strength it merely owes its extensive area of perception to the presence of a sensitive and intelligent population on the other hand the great japanese earthquake of eighteen ninety one disturbed only three hundred and thirty thousand square miles the californian earthquake of nineteen o six about three hundred and seventy thousand square miles and the messina earthquake of nineteen o eight about two hundred thousand square miles thus the alaskan earthquake of eighteen ninety nine must be ranked among the greatest of all recorded earthquakes this great earthquake however was not the earliest of the series so far as known the first earthquake occurred on september third at three thirty p m local time or september fourth at twelve twenty two a m greenwich mean time it was strong enough to be recorded in the seismological observatories of europe and other distant places there is some uncertainty as to the seat of this earthquake but as the coast is said to have been uplifted at yakutka one hundred miles west of yakutat it is possible that the central region was in the neighborhood of that place during the next week about fifty slight shocks were noticed near yakutat bay then on september tenth came two great earthquakes one about eight a m local time the other and greatest of all at twelve twenty two p m local time or nine forty p m greenwich mean time on the same day about fifty slighter shocks were observed both of the great shocks originated in and near yakutat bay but it is probable that the uplift of the coast occurred with the latter of the two as the earlier one was not accompanied by any sea wave Severe shocks also occurred on September 15th, 17th, 23rd, 26th, and 29th, intercalated among a large number of minor shakings to which little attention was naturally paid by the inhabitants of the district.

In the summer of 1905, a party of geologists sent by the United States Geological Survey visited Yakutat Bay.

The party was under the direction of the late Professor Ralph S. Tarr with Mr. Lawrence Martin as physiographic assistant.

Very early in their work they noticed dead mussels and barnacles adhering to the cliff, far above the reach of the present tides.

Had the barnacles died many years ago, they would have lost their hold on the rock, and indeed many of them had fallen onto the ledges below.