The geomorphic imprint of glacier surges into open-marine waters: Examples from eastern Svalbard

Ottesen, Dag; Dowdeswell, Julian A.; Bellec, VK; Bjarnadóttir, Lilja Rún

doi:10.1016/j.margeo.2017.08.007

Cited by 30 publications

(52 citation statements)

References 68 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Flink et al, 2015). This landform assemblage, or slight variations of it, is found at the marine margins of several other known surge-type glaciers in Svalbard and is suggested to be diagnostic of tidewater glacier surging (Ottesen et al, 2008(Ottesen et al, , 2017Flink et al, 2015).…”

Section: Little Ice Age Maximum Surgementioning

confidence: 70%

“…5.2.2 Interpretation: crevasse-squeeze ridges -The geometrical ridge networks are interpreted as crevasse-squeeze ridges, commonly observed at the submarine and terrestrial margins of surge-type glaciers (e.g. Sharp, 1985;Boulton et al, 1996;Evans and Rea, 1999;Ottesen and Dowdeswell, 2006;Ottesen et al, 2008Ottesen et al, , 2017Lovell et al, 2015;Farnsworth et al, 2016;Ingólfsson et al 2016). Crevasse-squeeze ridges are formed by the injection of deformable basal debris into vertical and near-vertical crevasses, as observed at the active ice margin (Fig.…”

Section: Interpretation: Ice-cored Terrain Formed By Subaerial Stagnamentioning

confidence: 99%

“…Farnsworth et al, 2017;Philipps et al, 2017;Streuff et al, 2017a). 4 The best way to determine possible surging that predates observational records is by investigating sediment-landform assemblages, as surge behaviour is known to produce a diagnostic suite of landforms (Evans and Rea, 1999;Ottesen et al, 2017). Numerous studies have investigated englacial, geomorphological and sedimentological evidence exposed at the receding margins of quiescent phase surge-type glaciers in Svalbard in order to better understand the processes that occur during surges (e.g.…”

Section: Introductionmentioning

confidence: 99%

“…Numerous studies have investigated englacial, geomorphological and sedimentological evidence exposed at the receding margins of quiescent phase surge-type glaciers in Svalbard in order to better understand the processes that occur during surges (e.g. Boulton et al, 1996Boulton et al, , 1999Glasser et al, 1998a;Bennett et al, 1999;Christoffersen et al, 2005;Larsen et al, 2006;Ottesen et al, 2008Ottesen et al, , 2017Kristensen et al, 2009a,b;Lovell et al, 2015;Sobota et al, 2016;Larsen et al, 2018;Lyså et al, 2018). For tidewater glacier surges, this evidence is typically recorded on the sea floor (e.g.…”

Section: Introductionmentioning

confidence: 99%

“…For tidewater glacier surges, this evidence is typically recorded on the sea floor (e.g. Solheim and Pfirman, 1985;Plassen et al, 2004;Ottesen et al, 2008Ottesen et al, , 2017Forwick et al, 2010;Flink et al, 2015Flink et al, , 2017Streuff et al, 2015Streuff et al, , 2017aBurton et al, 2016;Farnsworth et al, 2017). Field observations of the active phase of glacier surges are rare (e.g.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Multiple Late Holocene surges of a High-Arctic tidewater glacier system in Svalbard

Lovell

Benn

Lukas

et al. 2018

Quaternary Science Reviews

View full text Add to dashboard Cite

Most large tidewater glaciers in Svalbard are known to have surged at least once in the last few hundred years. However, very little information exists on the frequency, timing or magnitude of surges prior to the Little Ice Age (LIA) maximum in ~1900. We investigate the sedimentlandform assemblages produced by multiple advances of the Nathorstbreen glacier system (NGS) in order to reconstruct its Late Holocene surge history. The glacier has recently undergone one of the largest surges ever observed in Svalbard, advancing ~16 km from 2008 2 to 2016. We present flow velocities and ice-marginal observations (terminus change, proglacial geomorphological processes) from the later stages of this surge. A first detailed assessment of the development of a glaciotectonic mud apron within the fjord during a surge is provided. Geomorphological and sedimentological examination of the terrestrial moraine areas formed prior to the most recent surge reveals that at least two advances were responsible for their formation, based on the identification of a previously unrecognised ice-contact zone recorded by the distribution of sediment facies in coastal exposures. We distinguish between an outer, older advance to the distal part of the moraine system and an inner, younger advance to a position ~2 km upfjord. Radiocarbon dating of shells embedded in glaciotectonic composite ridges formed by the onshore bulldozing of marine mud during the outer (older) of the two advances shows that it occurred at some point during the interval 700-890 cal. yr BP (i.e. ~1160 AD), and not during the LIA as previously assumed. We instead attribute the inner (younger) advance to the LIA at ~1890.

show abstract

Section: Little Ice Age Maximum Surgementioning

confidence: 70%

Section: Interpretation: Ice-cored Terrain Formed By Subaerial Stagnamentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Multiple Late Holocene surges of a High-Arctic tidewater glacier system in Svalbard

Lovell

Benn

Lukas

et al. 2018

Quaternary Science Reviews

View full text Add to dashboard Cite

show abstract

Pattern, style and timing of British–Irish Ice Sheet retreat: Shetland and northern North Sea sector

Bradwell

Small

Fabel

et al. 2019

J Quaternary Science

View full text Add to dashboard Cite

The offshore sector around Shetland remains one of the least well‐studied parts of the former British–Irish Ice Sheet with several long‐standing scientific issues unresolved. These key issues include (i) the dominance of a locally sourced ‘Shetland ice cap’ vs an invasive Fennoscandian Ice Sheet; (ii) the flow configuration and style of glaciation at the Last Glacial Maximum (i.e. terrestrial vs marine glaciation); (iii) the nature of confluence between the British–Irish and Fennoscandian Ice Sheets; (iv) the cause, style and rate of ice sheet separation; and (v) the wider implications of ice sheet uncoupling on the tempo of subsequent deglaciation. As part of the Britice‐Chrono project, we present new geological (seabed cores), geomorphological, marine geophysical and geochronological data from the northernmost sector of the last British–Irish Ice Sheet (north of 59.5°N) to address these questions. The study area covers ca. 95 000 km2, an area approximately the size of Ireland, and includes the islands of Shetland and the surrounding continental shelf, some of the continental slope, and the western margin of the Norwegian Channel. We collect and analyse data from onshore in Shetland and along key transects offshore, to establish the most coherent picture, so far, of former ice‐sheet deglaciation in this important sector. Alongside new seabed mapping and Quaternary sediment analysis, we use a multi‐proxy suite of new isotopic age assessments, including 32 cosmogenic‐nuclide exposure ages from glacially transported boulders and 35 radiocarbon dates from deglacial marine sediments, to develop a synoptic sector‐wide reconstruction combining strong onshore and offshore geological evidence with Bayesian chronosequence modelling. The results show widespread and significant spatial fluctuations in size, shape and flow configuration of an ice sheet/ice cap centred on, or to the east of, the Orkney–Shetland Platform, between ~30 and ~15 ka BP. At its maximum extent ca. 26–25 ka BP, this ice sheet was coalescent with the Fennoscandian Ice Sheet to the east. Between ~25 and 23 ka BP the ice sheet in this sector underwent a significant size reduction from ca. 85 000 to <50 000 km2, accompanied by several ice‐margin oscillations. Soon after, connection was lost with the Fennoscandian Ice Sheet and a marine corridor opened to the east of Shetland. This triggered initial (and unstable) re‐growth of a glaciologically independent Shetland Ice Cap ca. 21–20 ka BP with a strong east–west asymmetry with respect to topography. Ice mass growth was followed by rapid collapse, from an area of ca. 45 000 km2 to ca. 15 000 km2 between 19 and 18 ka BP, stabilizing at ca. 2000 km2 by ~17 ka BP. Final deglaciation of Shetland occurred ca. 17–15 ka BP, and may have involved one or more subsidiary ice centres on now‐submerged parts of the continental shelf. We suggest that the unusually dynamic behaviour of the northernmost sector of the British–Irish Ice Sheet between 21 and 18 ka BP – characterized by numerous extensive ice sheet/ic...

show abstract

Lateglacial and Holocene glacier activity in the Van Mijenfjorden area, western Svalbard

Larsen

Lyså

Rubensdotter

et al. 2018

Arktos

View full text Add to dashboard Cite

The geomorphic imprint of glacier surges into open-marine waters: Examples from eastern Svalbard

Cited by 30 publications

References 68 publications

Multiple Late Holocene surges of a High-Arctic tidewater glacier system in Svalbard

Multiple Late Holocene surges of a High-Arctic tidewater glacier system in Svalbard

Pattern, style and timing of British–Irish Ice Sheet retreat: Shetland and northern North Sea sector

Lateglacial and Holocene glacier activity in the Van Mijenfjorden area, western Svalbard

Contact Info

Product

Resources

About