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Reconstructing ice‐flow fields from streamlined subglacial bedforms: A kriging approach
Author(s) -
Ng Felix S. L.,
Hughes Anna L. C.
Publication year - 2018
Publication title -
earth surface processes and landforms
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.294
H-Index - 127
eISSN - 1096-9837
pISSN - 0197-9337
DOI - 10.1002/esp.4538
Subject(s) - geology , bedform , drumlin , geomorphology , landform , lineation , ice stream , ice sheet , flow (mathematics) , paleontology , cryosphere , geometry , climatology , sediment , sediment transport , tectonics , sea ice , mathematics
The orientation of several landforms, e.g. drumlins, flutes, crag‐and‐tails, and mega‐scale glacial lineations, records the direction of the overlying ice flow that created them. Populations of such features are used routinely to infer former ice‐flow patterns, which serve as the building blocks of reconstructions of palaeo ice‐sheet evolution. Currently, the conceptualisation of flow patterns from these flow‐direction records is done manually and qualitatively, so the extractable glaciological information is limited. We describe a kriging method (with Matlab code implementation) that calculates continuous fields of ice‐flow direction, convergence, and curvature from the flow‐direction records, and which yields quantitative results with uncertainty estimates. We test the method by application to the subglacial bedforms of the Tweed Valley Basin, UK. The results quantify the convergent flow pattern of the Tweed Palaeo‐Ice Stream in detail and pinpoint its former lateral shear margins and where ice flowed around basal bumps. Ice‐flow parameters retrieved by this method can enrich ice‐sheet reconstructions and investigations of subglacial till processes and bedform genesis. © 2018 The Authors. Earth Surface Processes and Landforms published by John Wiley & Sons Ltd.