commit 467972b534028b29ca6e500a7b8bdc66621fe2df
parent 3e44a5a2cfb1e6e5a16c33ceb00d1a75eb626f4b
Author: Anders Damsgaard <anders@adamsgaard.dk>
Date: Tue, 3 Dec 2019 16:22:36 +0100
Update discussion with bed thickness speculation
Diffstat:
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/continuum-granular-manuscript1.tex b/continuum-granular-manuscript1.tex
@@ -305,7 +305,8 @@ There is a significant strengthening when the bed thickness $L_z$ begins to cons
\label{sec:discussion}
This study has the specific aim of quantifying advective sediment transport under shear.
As granular deformation is associated with finite length scales, it is crucial to include non-local terms in the granular model equations instead of applying earlier \emph{local} sediment models \cite<e.g.,>[] {daCruz2005, Jop2006, Forterre2008}.
-However, the modeled sediment flux may present an upper bound since we assume that there is a strong mechanical coupling between ice and bed.
+However, the modeled sediment flux presented here may present an upper bound since we assume that there is a strong mechanical coupling between ice and bed.
+If the subglacial sediment bed is a thin layer of $\sim$10 cm or less, our model predicts that the sediment itself will be comparatively strong (bulk friction vs.\ bed thickness in Fig.~S2).
Overpressurization and slip at the ice-bed interface may cause episodic decoupling and reduce bed deformation.
Interface slip is observed both under contemporary ice streams \cite<e.g.,>[] {Engelhardt1998}, and in deposits from past glaciations \cite<e.g.,>[] {Piotrowski2001}.
Still, we see the presented framework as a significant improvement of treating sediment advection in ice-flow models, but acknowledge that a complete understanding of the sediment mass budget requires improved models of ice-bed interface physics.
