A model for tidewater glacier undercutting by submarine melting

Slater, Donald; Nienow, Peter; Goldberg, David M.; Cowton, Tom; Sole, Andrew

doi:10.1002/2016gl072374

Cited by 49 publications

(63 citation statements)

References 32 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This assumption is supported by Slater et al (2017a), who showed that the shape of the submerged ice front does not have a significant feedback effect on plume dynamics or submarine melt rates. However, the same study suggests that the total ablation driven by submarine melting will increase www.the-cryosphere.net/12/609/2018/ The Cryosphere, 12, 609-625, 2018 due to the greater surface area available for melting.…”

Section: Plume Model and Undercuttingsupporting

confidence: 68%

Effects of undercutting and sliding on calving: a global approach applied to Kronebreen, Svalbard

et al. 2018

View full text Add to dashboard Cite

Abstract. In this paper, we study the effects of basal friction, sub-aqueous undercutting and glacier geometry on the calving process by combining six different models in an offlinecoupled workflow: a continuum-mechanical ice flow model (Elmer/Ice), a climatic mass balance model, a simple subglacial hydrology model, a plume model, an undercutting model and a discrete particle model to investigate fracture dynamics (Helsinki Discrete Element Model, HiDEM). We demonstrate the feasibility of reproducing the observed calving retreat at the front of Kronebreen, a tidewater glacier in Svalbard, during a melt season by using the output from the first five models as input to HiDEM. Basal sliding and glacier motion are addressed using Elmer/Ice, while calving is modelled by HiDEM. A hydrology model calculates subglacial drainage paths and indicates two main outlets with different discharges. Depending on the discharge, the plume model computes frontal melt rates, which are iteratively projected to the actual front of the glacier at subglacial discharge locations. This produces undercutting of different sizes, as melt is concentrated close to the surface for high discharge and is more diffuse for low discharge. By testing different configurations, we show that undercutting plays a key role in glacier retreat and is necessary to reproduce observed retreat in the vicinity of the discharge locations during the melting season. Calving rates are also influenced by basal friction, through its effects on near-terminus strain rates and ice velocity.

show abstract

Section: Plume Model and Undercuttingsupporting

confidence: 68%

Effects of undercutting and sliding on calving: a global approach applied to Kronebreen, Svalbard

et al. 2018

View full text Add to dashboard Cite

show abstract

“…This assumption is supported by Slater et al (2017), who showed that the shape of the submerged ice front does not have a significant feedback effect on plume dynamics or submarine melt rates. However, the same study suggests that the total ablation driven…”

supporting

confidence: 68%

Effects of undercutting and sliding on calving: a coupled approach applied to Kronebreen, Svalbard

Vallot¹,

Åström²,

Zwinger³

et al. 2017

Preprint

View full text Add to dashboard Cite

Abstract.In this paper, we study the effects of basal friction, sub-aqueous undercutting and glacier geometry on the calving process with six different models: a continuum-mechanical ice flow model (Elmer/Ice), a climatic mass balance model, a simple subglacial hydrology model, a plume model, an undercut model and a discrete particle model to investigate fracture dynamics (Helsinki Discrete Element Model, HiDEM). We also demonstrate the feasibility of reproducing the observed calving retreat 5 at the front of Kronebreen, a tidewater glacier in Svalbard, during a melt season. Basal sliding and glacier motion is addressed using Elmer/Ice while calving is modelled by HiDEM. An hydrology model calculates subglacial drainage paths and indicates two main outlets at relatively different rates. Depending on the discharge, the plume model computes frontal melt rates, which are iteratively projected to the actual front of the glacier at subglacial discharge locations. This produces undercutting of different sizes, as melt is concentrated close to the surface for high discharge and is more diffuse for low discharge. By testing 10 different configurations, we show that the geometry (frontal position and topography) controls the calving location while basal sliding controls the calving rate. Undercutting plays a key role in glacier retreat and is necessary to reproduce observed retreat in the vicinity of the discharge location.

show abstract

“…This means that the majority of the calving front is not directly exposed to melting within a plume, and instead melting must occur either by unforced (melt-driven) convection, which is thought to be very weak (Magorrian & Wells, 2016), or due to any additional fjord-wide circulation (Bartholomaus et al, 2013). Much of our understanding of tidewater glacier submarine melting therefore derives from models of plume dynamics (Carroll et al, 2016;Slater et al, 2017), and current parameterizations of submarine melting at tidewater glaciers Todd et al, 2018) used in process studies thus neglect fjord-wide circulation. This scarcity of ocean observations proximal to tidewater glaciers, combined with a lack of realistic models, has precluded quantification of the melting driven by fjord-wide circulation at Greenlandic tidewater glaciers.…”

Section: Introductionmentioning

confidence: 99%

Localized Plumes Drive Front‐Wide Ocean Melting of A Greenlandic Tidewater Glacier

Slater

Straneo

Das

et al. 2018

Geophysical Research Letters

Self Cite

160

View full text Add to dashboard Cite

Recent acceleration of Greenland's ocean‐terminating glaciers has substantially amplified the ice sheet's contribution to global sea level. Increased oceanic melting of these tidewater glaciers is widely cited as the likely trigger, and is thought to be highest within vigorous plumes driven by freshwater drainage from beneath glaciers. Yet melting of the larger part of calving fronts outside of plumes remains largely unstudied. Here we combine ocean observations collected within 100 m of a tidewater glacier with a numerical model to show that unlike previously assumed, plumes drive an energetic fjord‐wide circulation which enhances melting along the entire calving front. Compared to estimates of melting within plumes alone, this fjord‐wide circulation effectively doubles the glacier‐wide melt rate, and through shaping the calving front has a potential dynamic impact on calving. Our results suggest that melting driven by fjord‐scale circulation should be considered in process‐based projections of Greenland's sea level contribution.

show abstract

A model for tidewater glacier undercutting by submarine melting

Cited by 49 publications

References 32 publications

Effects of undercutting and sliding on calving: a global approach applied to Kronebreen, Svalbard

Effects of undercutting and sliding on calving: a global approach applied to Kronebreen, Svalbard

Effects of undercutting and sliding on calving: a coupled approach applied to Kronebreen, Svalbard

Localized Plumes Drive Front‐Wide Ocean Melting of A Greenlandic Tidewater Glacier

Contact Info

Product

Resources

About