While this global database of glaciers represents the first comprehensive inventory, the paper about the project notes that there are several outstanding tasks. The Randolph Glacier Inventory: a globally complete inventory of glaciers“. More detail about the attribute information is detailed in the PDF, “Supplementary information for Each glacier outline was assigned twelve attributes including an ID, the lat/long of the centroid of the glacier, the date of the image from which the glacier was outlined, the type of the glacier, and the area of the glacier. Other imagery sources included ASTER, IKONOS, and SPOT 5 high resolution imagery. The Landsat archives formed the dominant satellite imagery source for the undertaking. Most of the glacier outlines were extracted from freely available satellite imagery. A review of the project, methodology for creating the inventory of glaciers, and next steps was recently published in the Journal of Glaciology: “ The Randolph Glacier Inventory: a globally complete inventory of glaciers“. The completed dataset is known as the Randolph Glacier Inventory (RGI). The GIS dataset was rapidly developed in less than two years in order to meet the requirements of the Fifth Assessment of the Intergovernmental Panel on Climate Change (IPCC). Timothy Warner as editor and three anonymous reviewers whose insightful comments greatly improved the manuscript.An international group of seventy scientists hailing from more than eighteen countries have created the first global datasets of the world’s glaciers (not including the ice sheets of Greenland and Antarctica. We thank Toby Benham for assistance with the CAGE data. Boulder, Colorado, USA: NASA DAAC at the National Snow and Ice Data Centre. CAGE data were collected under NERC grant NE/K004999, and NASA OIB data were taken from Leuschen et al. We thank the developers at the California Institute of Technology for the freely accessible COSI-corr plugin for ENVI ( ). Glacier outlines for the Prince of Wales Ice Field and Trinity-Wykeham Glacier catchment were downloaded from the GLIMS data viewer ( ). Landsat and ASTER imagery were downloaded from the Earth Explorer Data portal ( ), as well as the ASTER GDEM. The bedrock topography thus has a primary influence on the nature of the changes in ice dynamics observed over the last decade. We observe supraglacial lakes that drain at the end of summer and are concurrent with a reduction in glacier velocity, suggesting hydrological connections between the surface and the bed significantly impact ice flow. Further, the presence of bedrock ridges induces crevassing on the surface and provides a direct link for surface meltwater to reach the bed. Furthermore, by comparing the separate glacier troughs we suggest that the dynamic changes are modulated by both lateral friction from the valley sides and the complex geometry of the bed. The combination of thinning, acceleration and retreat of the TWG suggests that a dynamic thinning mechanism is responsible for the observed changes, and we suggest that both glaciers have transitioned from fully grounded to partially floating. We show that surface flow rates at both Trinity Glacier and Wykeham Glacier doubled over 16 years, during which time the ice front retreated 4.45 km. We use measurements of d h/d t from ICESat (2003–2009) and CryoSat-2 (2010–2016) repeat observations to show that rates of surface lowering increased from 4 m yr −1 to 6 m yr −1 across the lowermost 10 km of the TWG. This study explores the relationship between surface elevation changes (d h/d t), glacier velocity changes (d u/d t), and bedrock topography at the Trinity-Wykeham Glacier system (TWG), Canadian High Arctic, using a range of satellite and airborne datasets. However, our understanding of how the processes governing mass loss will respond to climate warming remains incomplete. Mass loss from glaciers and ice caps represents the largest terrestrial component of current sea level rise.
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