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Mature dead-ice has been overridden repeatedly by the Brúarjökull glacier, and multiple generations of ice-cored landforms occur, with ice cores originating at least from glacier surges in 1963-1964, 1890 and 1810. Ice-cores are located on the proximal slopes of end moraines and in the valleys, as ice-cored outwash and eskers, ice-cored drumlins and ice-cored moraine patches. This dictates that the sediments and internal architecture might not always match their end-products as de-icing progresses. Analysis of multi-temporal aerial photographs integrated with annual field measurements showed that the time required for a total de-icing in the forefield exceeds the duration of the quiescent phases between the surges, even in the current climate at the limit of permafrost. Quantifying melting progression suggests that complete de-icing of ice-cored landforms is not likely to occur. The mean de-icing rate is c. 9.8 cm/yr in 1890 ice-cored moraines, and c. 17.7 cm/yr in 1963-1964 ice-cored moraines. Backwasting of ice-cored slopes (c. 30 cm/yr) is the fastest melt process. Long-term downwasting rates derived from multi-temporal digital elevation models provide a superior insight into the impact of multiple glacier surges on the formation of dead-ice moraines in front of Brúarjökull. [ABSTRACT FROM AUTHOR]

Surging glaciers are potential analogues for land-terminating palaeo-ice streams and surging ice sheet lobes, and research on surge-type glaciers is important for understanding the causal mechanisms of modern and past ice sheet instabilities. The geomorphic signatures left by the Icelandic surge-type glaciers vary and range from glaciotectonic end moraines formed by folding and thrusting, crevasse-squeeze ridges, concertina eskers, drumlins and fluted forefields, to extensive dead-ice fields and even drift sheets where fast ice-flow indicators are largely missing. We outline some outstanding research questions and review case studies from the surge-type outlets of Brúarjökull, Eyjabakkajökull and Tungnaárjökull (Vatnajökull ice cap), Múlajökull and Sátujökull (Hofsjökull ice cap), Hagafellsjökull and Suðurjökull (Langjökull ice cap), Kaldalónsjökull, Leirufjarðarjökull and Reykjarfjarðarjökull (Drangajökull ice cap), as well as the surge-type cirque glaciers in northern Iceland. We review the current understanding of how rapid ice flow is sustained throughout the surge, the processes that control the development of the surge-type glacier landsystem and the geological evidence of surges found in sediments and landforms. We also examine if it is possible to reconstruct past surge flow rates from glacial landforms and sediments and scale-up present-day surge processes, landforms and landsystems as modern analogues to past ice streams. Finally, we also examine if there is a climate/mass-balance control on surge initiation, duration and frequency. [ABSTRACT FROM AUTHOR]