170 



KNOWLEDGE. 



June, 1915. 



some of the material carried away iti extensive 

 beaches. In many places the rock-benches are 

 now elevated from ten to forty feet, and form long 

 stretches from two to forty feet in width. At the 

 bases of the cliffs behind may be seen the sea-caves 

 and chasms that had been worn in them before the 

 uplift occurred. The beaches were also raised and 

 are still preserved where they ha\'e nul since been 

 cut into by streams and waves. Sand-dunes on 

 the west side of Disenchantment Bay have been 

 raised beyond the reach of further supplies of sand, 

 and in consequence grasses have soon taken root 

 upon their surface. In 1909, or ten years after the 

 earthquake, the belt of dunes had lost all trace of 

 its former condition except the hummocky surface 

 and the sandy soil. 



^^'hile the cliffs were being worn back and the 

 rock-benches planed away the streams flowing 

 into Yakutat Bay and its branches were building 

 up their deltas. Many of these deltas are now laid 

 bare above the sea, and gullies are being formed in 

 them b\' the streams, while the seaward slopes are 

 being cut back by the waves into low cliffs. In 

 Russell Fiord a small island before the earthquake 

 used to be connected by a sand-spit with the 

 mainland at low tide. The spit is now so much 

 uplifted that the highest tides cannot cover it. 

 To the north of Haenke Island there used to be 

 two submerged reefs which before the earthquake 

 were never visible. They are now uncovered at 

 low tide. Again, in the cove to the south-east of 

 Knight Island four small islets have appeared, the 

 two largest being four hundred and fiftj^ feet in 

 length. The native canoemen assert that all four 

 were submerged at high tide before the earthquakes, 

 while two could only be seen at low tide. Two of 

 them are now exposed at all states of the tide and 

 the others between mid and low tides. In many 

 other parts of the inlet, and especially on the east 

 side of Disenchantment Bay, there are numerous 

 channels between small reefs and stacks and the 

 shore along which, according to the natives, boats 

 could formerly pass, but which now are no longer 

 navigable. 



There is of course nothing in the physiographic 

 e\idence to indicate the exact date at which the 

 uplifts described took place. That it occurred, 

 however, not long ago is shown by the appearance 

 of the elevated ground. In the uplifted deltas and 

 raised beaches — that is, in ground formed of soft or 

 loose material — streams and waves soon wore away 

 the surface. By 1909, or within ten years, many 

 raised beaches were destroyed, and the sand-dunes, 

 as already mentioned, were covered with grasses. 

 But in the rock-benches and cliffs the effect has 

 been but slight. Chasms are just beginning to 

 form in the cliffs at the new sea-level ; but in 1 905 

 the sea had not cut an appreciable chff or rock- 

 bench anywhere, and the uplifted benches are only 

 slightly modified by the streams that flow across 

 them. 



For the purpose of measuring the extent of the 



uplift the biological evidence is even of greater 

 service than the phenomena described above. In 

 approaching the coast in a boat the white shells of 

 dead barnacles are a striking fcat\ire. Many of the 

 barnacles are still firmly attached to the rocks, 

 the valves being often held together by the organic 

 tissue. In places they are far more abundant 

 tiian the living forms at the present sea-level. 

 Moreover, few of the latter are more than three- 

 eighths of an inch in diameter, while many of the 

 dead barnacles are an inch and a half across. 

 Dead mussels are even more abundant and almost 

 as widely distributed as the barnacles. They 

 resembled, and were indeed at lirst mistaken for, 

 clusters of blue flowers attached to ledges eighteen 

 feet or more above the present sea-level. They 

 were often found adhering to the rocks by the 

 hairlike byssus, and the preservation of so delicate 

 a structure until 1905 is another indication of the 

 recency of the movement. Besides barnacles and 

 mussels, limpets were occasionally found in 1905 

 attached to uplifted ledges of rock. In certain 

 parts of the west side of Disenchantment Bay 

 there were also seen what looked from a distance 

 like broad horizontal bands of whitewashed rock, 

 but which pro\ed to be the bleached remains of a 

 pink bryozoan that grows in tidal pools and below 

 the low-tide level. 



One curious result of the uplift is the mixture 

 in one spot of land and sea organisms. The 

 remains of barnacles, mussels, and bryozoans, 

 which live only in the sea, now rest in spots which 

 have been invaded by the willow and alder, the 

 wild geranium and other land-plants. On nearly 

 all the raised beaches and deltas, and on some of 

 the uplifted rock-benches, these land-plants are to 

 be found. The scattered condition of the flowering 

 annuals and perennials and the grasses indicates 

 the recency of the uplift, which is clearly proved by 

 the woody shrubs, such as the willow and the alder. 

 These are without exception small, and of all that 

 were cut down in 1905 none showed more than 

 five annual rings, and most had onl)' three or four. 

 " Evidently," as Messrs. Tarr and Martin remark, 

 " these shore lines had been open for occupation 

 by land-plants for only four or flv'e years. The 

 earthquake was in the autumn six years before." 



The destruction of life during the earthquakes of 

 1899 must have been very great. Numberless 

 fishes were killed by the mere force of the shock. 

 The seismic sea-waves, which swept over the land 

 after the principal earthquake, uprooted trees and 

 destroyed vegetation by saturating the roots with 

 salt water. But, above all, there was a wholesale 

 destruction of various marine forms — barnacles, 

 mussels, and so on — by their uplift from the sea. 

 When this uplift amounted to as much as ten feet 

 or more, the intertidal animals were all killed, and 

 their place has been supplied only scantily, if at 

 all, by others, whose diminutive forms point to 

 the shortness of their lives, and therefore to the 

 recency of their migration. Thus, the state of 



