The determination of glacier speed by time-lapse photography under unfavorable conditions

• Published in: Journal of Glaciology
• Main Authors: Harrison, W.D., Echelmeyer, K.A., Cosgrove, D.M., Raymond, C. F.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press (CUP) 1992
• Subjects: Earth-Surface Processes; alaska range; glacier; Journal of Glaciology; Alaska
• Online Access: http://dx.doi.org/10.1017/s002214300000366x; https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S002214300000366X

Abstract Two practical problems in the use of time-lapse photography for the measurement of speed were encountered during the recent surge of West Fork Glacier in the central Alaska Range, Alaska, U.S.A. The first is severe rotational camera instability; we show how natural, unsurveyed features on the valley wall can be used to make the necessary corrections. The second problem is the computation of absolute speed when many different, unsurveyed glacier-surface features are used as targets. We give a method for connecting the data obtained from different targets, and for determining the scale using limited information obtained by surveying. Severe systematic errors can occur unless the angle between the axis of the lens and the direction of horizontal motion is determined.