Laserfiche WebLink
<br />be seen from the Slttmgullion Pass road at location A. The instability of <br /> <br />this flow is indicated by the leaning trees that dot its surface. As the <br /> <br />trees are growing, the ground beneath them is mov1ng, caus1ng the trees to <br /> <br /> <br />lean. Any d1sturbance of a growing tree's <br /> <br /> <br />root system can cause a weakness 1n the <br /> <br />root system's ability to support the <br /> <br />~~lF. .;.~~.:.:'. <br />""...... .. <br /> <br />iJ ..... ",0. <br />.', .... .. ': \.... <br /> <br />J~<'~:.i/.~. ;::,~;:':: . <br /> <br /> <br />. _ ::. ~ ~ a., .. <br />,,l.. \,,\(\ . "-,, . '* . .. ~ <br /> <br /> <br />S'tD\:)\e UF\s-\.'D'o\e <br /> <br />tree. CrOOkedly grOWing trees are <br />excellent oriteria for locating mass- <br /> <br />., <br />.- <br />'" <br />~. ~~ <br />- ....1., <br /> <br />wasting features that fall into the !12! <br />moving types (Appendix, p. 18). <br /> <br />VELOCITY OF THE ACTIVE EARTHFLOW <br /> <br />Crandell and Varnes studied the velocity of the active earthflow in <br /> <br /> <br />three ways: (1) the displacements of trees; (2) measurements aotually made <br /> <br /> <br />on the ground and; (3) by an automatic time-lapse motion picture camera. <br /> <br /> <br />(1) The displacements of trees were discerned by a compar1son of <br /> <br /> <br />aer1al photographs made in 1939 and in succeeding years. The positions of <br /> <br />the trees in the later photographs were correlated to their earlier positions <br /> <br />6 <br /> <br />o <br />o <br />o <br />0> <br />c.:> <br />c:n <br />