PnYSIOGBAPHY AND GEOLOGY OF THE ISLANDS. 11 



Earthquake shocks are frequent all along the Kuril chain of 

 islands. I have experienced them on shore and on board ship, both 

 when at anchor and when under way. Perhaps when a shock is 

 felt on board a ship that is under way, the disturbance causing it 

 is more likely to be a submarine eruption rather than an earth- 

 quake. When, however, a vessel is lying at anchor, she is attached 

 to the earth by her anchors and cables, and an earthquake is com- 

 municated to the vessel through them. 



On July 12, 1884, when sailing along the islands, about four 

 miles to the westward of the Srednoi rocks, we felt the effects 

 of a series of earthquake shocks, or more probably the commotion 

 caused by a submarine eruption. About five o'clock p.m., when in 

 my cabin, a noise like the running out of a line over a vessel's rail 

 was heard. I thought a cast of the lead was being taken, as a 

 thick fog prevailed at the time, and took no further notice. Some 

 little time afterwards the same kind of sound again occurred, but 

 much louder. On making inquiries on deck, I found that no one 

 had noticed it. About six o'clock we were sitting down to our 

 evening meal, when a violent trembling of the vessel, accompanied 

 by a sound like steam blowing off from a boiler, took place. All 

 hands rushed on deck, thinking the vessel had run on a reef; but 

 all was quiet and as usual, the schooner slowly forging ahead with 

 a very light south-south-east breeze. Several casts of the lead were 

 taken, but no bottom found with all the line out. This same rush- 

 ing noise and trembling of the vessel continued for nearly two 

 hours, at intervals of about fifteen minutes, each time lasting about 

 thirty seconds. No disturbance of the sea was noticed, but on 

 account of the fog our range of vision was very limited. The 

 temperature of the sea was as usual, 36° Fahr. 



Although to those below the rushing noise like the blowing off 

 of a steam boiler appeared to be very loud, those on deck could not 

 hear it, notwithstanding that the trembling of the vessel was 

 equally perceptible there. The sound must, therefore, have been 

 communicated through the water, and was undoubtedly due to a 

 submarine disturbance of some kind. 



Some daj^s after I visited the craters of Ushishir and Rashau, Init 

 they showed no signs of increased activit3^ 



