Extracting recent short-term glacier velocity evolution over Southern Alaska from a large collection of Landsat data

Abstract

The measurement of glacier velocity fields using repeat satellite imagery has become a standard method of cryospheric research. However, the reliable discovery of important glacier velocity variations on a large scale is still problematic, because time-series span different time intervals and are partly populated with erroneous velocity estimates. In this study we build upon existing glacier velocity products from the GoLIVE data set (https://nsidc.org/data/golive) and compile a multi-temporal stack of velocity data over the Saint Elias Mountain range and vicinity. Each layer has a time separation of 32 days, making 5 it possible to observe details such as within-season velocity change over an area of roughly 150 000 km 2 . Our methodology is robust as it is based upon a fuzzy voting scheme applied in a discrete parameter space. In this way it is able to filter multiple outliers. The multi-temporal data stack is then smoothed to facilitate interpretation. This results in a spatio-temporal dataset where one can identify short-term glacier dynamics on a regional scale. The goal is not to improve accuracy or precision, but being able to extract the timing and location of ice flow events such as glacier surges. Our implementation is fully automatic 10 and the approach is independent of geographical area or satellite system used. We demonstrate this automatic method on a large glacier area in Alaska/Canada. Within the Saint Elias and Kluane mountain ranges, several surges and their propagation characteristics are identified and tracked through time, as well as more complicated dynamics in the Wrangell's mountains.Copyright statement. TEXT

Self‐Entrainment Motion of a Slow‐Moving Landslide Inferred From Landsat‐8 Time Series

“…However, exploitation of the full data redundancy to generate robust optical time series has been little utilized for modern multitemporal optical satellite data sets. Recently, Altena et al () made use of a similar time series inversion approach to Bontemps et al (), to study ground deformation of glaciers using Landsat‐8 imagery. In this study, we develop robust time series using Landsat‐8 data to derive spatiotemporal kinematic variations of a slow‐moving landslide.…”