Ice Flow Direction

with short-term fluctuations limited to ±2 logger resolutions (ca. 0.2 mm).

The velocity time series (Fig. 66.2) for anchor P3 at site 1 shows the fastest velocities occurring in the early afternoon, coinciding with higher air temperatures, and long periods of zero motion overnight. At site 2, an increase in velocity occurs during higher air temperatures on 12 September (Fig. 66.3), but the velocities of both anchors are characterized by highly unsteady motion (Fig. 66.4), and lack the long periods of zero motion seen at site 1. Very small, negative velocities in Fig. 66.4 are due to instrumental noise and represent voltage fluctuations of ±2 logger resolutions.

At site 2 the upper anchor moved more smoothly than the lower: this is illustrated by the ratios of the standard deviation to the mean velocity, which are 1.99 and 4.97 for the upper and lower anchors respectively.

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