Guide books of excursions in Canada1-10 . he front and justabove the ice surface, which is barren of vegetation. Fromsuch a condition one infers that the ice has withdrawnfrom such areas so recently that vegetation has not yethad time to encroach upon it. The extent of shrinkageindicated by this class of evidence varies with differentglaciers, but it is present to some degree in the neighbor-hood of almost all the glaciers studied, and in some itindicates a great and long-continued shrinkage. Thisis particularly true in Nunatak and Russell fiords, asalready stated in the preceding section. Her
Guide books of excursions in Canada1-10 . he front and justabove the ice surface, which is barren of vegetation. Fromsuch a condition one infers that the ice has withdrawnfrom such areas so recently that vegetation has not yethad time to encroach upon it. The extent of shrinkageindicated by this class of evidence varies with differentglaciers, but it is present to some degree in the neighbor-hood of almost all the glaciers studied, and in some itindicates a great and long-continued shrinkage. Thisis particularly true in Nunatak and Russell fiords, asalready stated in the preceding section. Here it is certainthat in the last century the resession has amounted tomany miles. Recent Advances of Nine Glaciers. In 1905 Tarr and Martin found that, while the generalcondition of recession characterized the great majorityof the Yakutat Bay glaciers, Galiano glacier presentedconvincing evidence of change to activity in the intervalsince it was photographed by Russell in 1890. Then ithad a stagnant piedmont bulb on whose ablation moraine. 152 a dense forest of alder and cottonwood grew, proved bothby Russells description and his photographs and alsoshown by Boundary Survey photographs in 1895. Thishad entirely disappeared in 1905, but the piedmont bulbwas again stagnant and covered by ablation moraine,though with only young alders scattered here and glaciers, for instance Atrevida, the nearestto the west, and Black glacier to the east, gave no evidenceof similar change, and no such evidence was found in anyother glaciers, though it was found later that the smallice tongue north of Haenke glacier had a period of cre-vassing and advance in 1901. In 1906 Tarr found four glaciers absolutely transformedand all the others unchanged. The glaciers that were soaltered in the brief interval of ten months are, namedfrom west to east: (1) Marvine glacier and the easternlobe of Malaspina glacier that is supplied by the Marvine;(2) Atrevida glacier; (3) Haenke glacier; and
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectgeology, bookyear1913
