Glacial landforms and their implications for glacier dynamics in Rijpfjorden and Duvefjorden, northern Nordaustlandet, Svalbard

Abstract

Observations of subglacial landforms yielding the configuration and dynamics of former ice‐flows have for the first time been made in Rijpfjorden and Duvefjorden, Nordaustlandet, Svalbard, using sub‐bottom acoustic, swath‐bathymetric data and sediment cores. Five acoustic‐stratigraphic units were distinguished suggesting the presence of a complete glacial–postglacial succession in the central fjord basins. 14C ages from the sediments indicate that the inner Rijpfjorden and central Duvefjorden were deglaciated before ca. 10.6 cal ka BP and 11.0 cal ka BP, respectively. Maximum sediment thickness in Rijpfjorden and Duvefjorden is 26 m, resulting in sediment accumulation rates of ca. 66 cm ka−1. The landform record suggests that the ice streaming in both fjords was topographically controlled. The considerably deeper basin and higher elongation ratios of the crag‐and‐tails in Duvefjorden are linked to the faulted bedrock and possibly to somewhat larger ice stream and/or more focused ice‐flow compared to that in Rijpfjorden. De Geer moraines suggest slower retreat of a grounded ice margin from shallow areas of Rijpfjorden. In deeper areas of the fjords, the glaciers were probably floating, resulting in the lack of ice‐marginal transverse landforms. The ice margin retreat from these areas was probably relatively rapid and dominated by calving.

Late Cenozoic Erosion Estimates for the Northern Barents Sea: Quantifying Glacial Sediment Input to the Arctic Ocean

“…A series of canyons at the lower slope of the Nordenskjold Trough indicate that smaller‐scale slope failure events dominated. In addition, gullies, channels, and sediment lobes are documented from the Albertini and Kvitøya Troughs by Fransner, Noormets, Flink, Hogan, O'Regan, et al () and Fransner et al () that is in agreement with slope instability. Some parts of the canyons are relatively smooth, which may indicate the deposition by contour currents.…”

“…Glacial landforms resulting from ice sheet advance and retreat during the last glacial period characterize the northern Barents Sea continental shelf (Batchelor et al, ; Dowdeswell, Ottesen, et al, ; Fransner, Noormets, Flink, Hogan, O'Regan, et al, ; Hogan et al, ). These include megaflutes, drumlins, and iceberg ploughmarks, with various orientations and scales.…”

Holocene glacial evolution of Mohnbukta in eastern Spitsbergen

“…-The large transverse ridges are interpreted as terminal moraine ridges based on their shape and dimensions. Many tidewaterglacier landform assemblages in Svalbard contain terminal moraine ridges of comparable height to those in Mohnbukta (Ottesen & Dowdeswell 2006;Kristensen et al 2009;Flink et al 2015Flink et al , 2017. Large moraine ridges can form as marine muds are pushed or bulldozed in front of the advancing glacier during climatically induced advances or, as common in many Svalbard examples, during glacial surges (Ottesen et al 2008;Kristensen et al 2009;Flink et al 2015;Streuffet al 2015).…”

“…; Fransner et al . ). None of the fjords or bays in central east Spitsbergen, such as Wiche‐, Mohn‐, Duner‐ or Agardhbukta has, however, been investigated with marine geophysical or sedimentological methods.…”

“…1A) is, however, considerably less well known, mainly because these areas are covered by sea ice during large parts of the year and are logistically harder to access. A few studies have used marine geophysical methods to investigate Holocene glacier dynam-ics on the east coast of Spitsbergen (Noormets et al 2016a, b;Streuff et al 2017) as well as in Nordaustlandet (Solheim 1985;Robinson & Dowdeswell 2011;Flink et al 2017;Fransner et al 2017). None of the fjords or bays in central east Spitsbergen, such as Wiche-, Mohn-, Duner-or Agardhbukta has, however, been investigated with marine geophysical or sedimentological methods.…”