June 25, 1904 Earthquake: Off Kamchatka, Russia

Apparently these were the first tsunami-generating earthquakes in the Kurile-Kamchatka zone that were recorded by seismic stations. As early as 1907 a member of the Permanent Central Seismological Commission, E. Rosental, made an attempt to analyze and put together the data from instrumental observations of the catastrophic earthquakes of June and July 1904, in Kamchatka. Having gathered reports of the time of arrival of the waves at seismological stations located in various parts of the world (several dozen stations), he was able to establish the correspondence between the shocks that were felt at the Petropavlovsk lighthouse and those recorded by instruments. He did not, however, succeed in determining the positions of the epicenters of the quakes.

B. Gutenberg and C. Richter worked over the instrumental data again, and with average values of the coordinates of the epicenter of 52N 150E and of intensity M=8 they obtained the following times of occurrence (Greenwich time) of the main June earthquakes: on the 25th (new style) at 14 hrs 45 min, on the 25th at 21 hrs 00 min, on the 27th at 00 hrs 09 min.

Descriptive material on the earthquakes is not abundant. There is a note by an eyewitness, the publisher of the newspaper "Priamurskie Vedomosti" and former Kamchatka regional commander, A. Sil'nitsky, and the observations of the keeper of the Petropavlovsk lighthouse, M. Kosachev.

Sil'nitsky, after an account of the volcanic activity which preceded the earthquakes, testifies:

"On June 1 [14 new style] at Petropavlovsk there began daily underground shocks. With each day they became more frequent and stronger and reached their greatest force on the night of the 12th [25th] to the 13th [26th] of June.

"At three o'clock in the morning [local time, 1625 June 25 Greenwich time] of that night all Petropavlovsk was awakened by a fearful underground rumbling, which shook the houses broke window panes, and brought chimneys crashing down on the roofs. At that time the ground oscillated in a horizontal direction but so strongly that the rocking could be felt by the legs of the frightened Petropavlovskites, when they ran out of their creaking, shaking houses. The phenomenon continued for more than a minute.

"At seven o'clock in the morning the earthquake was repeated. At that time it was accompanied by the following phenomena: on the glassy surface of Avacha Bay there arose a huge wave which, reaching the shore, threw the boats and sloops which were drawn up there 30 sazhens farther up; the coastal bluffs surrounding the entrance to the Bay of Avacha were shattered and masses of earth fell into the sea with a roar.

Although the shocks continued even after that, with greater or lesser intervals, the whole day of June 13 [26] and into the 14th [27], they were weaker, and on June 15 [28] the underground shocks ceased."

(above from Ref #414)