Introduction
Introduction Statistics Contact Development Disclaimer Help
t013-neel.txt - adamsgaard.dk - my academic webpage
git clone git://src.adamsgaard.dk/adamsgaard.dk
Log
Files
Refs
README
LICENSE
---
t013-neel.txt (4761B)
---
1 Today, [1]Indraneel Kasmalkar had his paper published in [2]Journal of
2 Geophysical Research: Earth Surface. Congratulations Neel! He used my so…
3 [3]sphere, and sheared a granular assembledge with a non-trivial forcing…
4 order to learn more about subglacial sediment behavior.
5
6 Abstract
7
8 Shear Variation at the Ice-Till Interface Changes the Spatial Distri…
9 of Till Porosity and Meltwater Drainage
10
11 Indraneel Kasmalkar(1), Anders Damsgaard(2), Liran Goren(3), Jenny S…
12 (1,4,5)
13
14 1: Department of Computational and Mathematical Engineering, Stanford
15 University, CA, USA
16 2: Department of Geoscience, Aarhus University, Denmark
17 3: Department of Earth and Environmental Sciences, Ben-Gurion Univer…
18 the Negev, Beer-Sheva, Israel
19 4: Department of Geophysics, Stanford University, CA, USA
20 5: Department of Civil and Environmental Engineering, Stanford Unive…
21 CA, USA
22
23 Plain-language summary:
24 The ice at the base of certain glaciers moves over soft sediments th…
25 route meltwater through the pore spaces in between the sediment grai…
26 ice shears the sediment, but it is not clear if this slow shearing is
27 capable of changing the structure or volume of the pore space, or th…
28 of the meltwater that flows through the sediment. To study the relat…
29 between the shearing of the sediment and the changes in its pore spa…
30 use computer simulations that portray the sediment as a collection of
31 closely packed spherical grains, where the pores are filled with mel…
32 To shear the simulated sediment, the grains at the top are pushed wi…
33 fixed speeds in the horizontal direction. Despite the slow shear, wh…
34 generally thought of as having no effect on pore space, our results …
35 that shearing changes the sizes of the pores in between the grains, …
36 large pores are formed near the top of the sediment layer. If the gr…
37 the top are pushed with uneven speeds, then the largest pores are fo…
38 the areas where grain speeds vary the most. We show that the exchang…
39 meltwater between neighboring pores is faster than the movement of t…
40 grains, indicating that the meltwater can adjust quickly to changing…
41 space.
42
43 Abstract:
44 Many subglacial environments consist of a fine-grained, deformable s…
45 bed, known as till, hosting an active hydrological system that routes
46 meltwater. Observations show that the till undergoes substantial she…
47 deformation as a result of the motion of the overlying ice. The defo…
48 of the till, coupled with the dynamics of the hydrological system, is
49 further affected by the substantial strain rate variability in subgl…
50 conditions resulting from spatial heterogeneity at the bed. However,…
51 not clear if the relatively low magnitudes of strain rates affect th…
52 structure or its hydrology. We study how laterally varying shear alo…
53 ice-bed interface alters sediment porosity and affects the flux of
54 meltwater through the pore spaces. We use a discrete element model
55 consisting of a collection of spherical, elasto-frictional grains wi…
56 water-saturated pore spaces to simulate the deformation of the granu…
57 bed. Our results show that a deforming granular layer exhibits subst…
58 spatial variability in porosity in the pseudo-static shear regime, w…
59 shear strain rates are relatively low. In particular, laterally vary…
60 shear at the shearing interface creates a narrow zone of elevated po…
61 which has increased susceptibility to plastic failure. Despite the c…
62 in porosity, our analysis suggests that the pore pressure equilibrat…
63 near-instantaneously relative to the deformation at critical state,
64 inhibiting potential strain rate dependence of the deformation cause…
65 bed hardening or weakening resulting from pore pressure changes. We …
66 shear variation to porosity evolution and drainage element formation…
67 actively deforming subglacial tills.
68
69 Links and references:
70
71 • [4]Publication on journal webpage (closed access)
72 • [5]Preprint PDF
73 • [6]Simulation software
74 • [7]Visualization of example simulation
75
76
77 References:
78
79 [1] mailto:[email protected]
80 [2] https://agupubs.onlinelibrary.wiley.com/journal/19422466
81 [3] https://src.adamsgaard.dk/sphere
82 [4] https://doi.org/10.1029/2021JF006460
83 [5] https://adamsgaard.dk/papers/Kasmalkar%20et%20al%202021%20Shear%20va…
84 [6] https://src.adamsgaard.dk/sphere
85
You are viewing proxied material from mx1.adamsgaard.dk. The copyright of proxied material belongs to its original authors. Any comments or complaints in relation to proxied material should be directed to the original authors of the content concerned. Please see the disclaimer for more details.