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Background |
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Model Analysis |
Discussions and Conclusions |
Stage 3: Piedmont Flow
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Phase 3 Analyses |
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| Like in transition flow, velocity
in piedmont flow is centered just above the valley-to-plain transition, with
deceleration at the toe on the flat continental plain and towards the walls.
Note that velocity contours parallel the banding in the Flubber. The
density of data points is much higher in the piedmont flow analyses than in
the transition flow due to the addition of markers (see figure to left).
The large region of uniform velocity near the toe is well contrained
by data points. |
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Compression/Tension |
Compression/Tension |
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| Large blue area shows a region
of extension due to lateral spreading of the glacier to fill space between
the walls on the continental plain. This extension is an order of magnitude
lower than extension during the valley-piedmont transition because the Flubber
is confined by the side walls. Red areas show regions of compression
where the expanding glacier meets the side walls, although knoting of the
contours in these areas suggest that they may not be reliable. |
Area of compression (red) at
the mouth of the valley is due to a decrease in the y-component of velocity
as the glacier moves to the lower surface slope of the continental plain.
Two regions of extension (blue) along the side walls have created folds in
the x-y plane similar to those observed on the Malaspina. |
The shear strain still shows
oppositely oriented shear due to drag along the walls with minimal shear
along the center axis. Note that the shear strain fields are deteriorating
as the Flubber moves onto the continental plain. |
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| Low dilatation during piedmont
flow as observed for valley and transition flow. |
Continued clockwise and counterclockwise
rotation along the left- and right-hand walls, respectfully, as was observed
in valley and transition flow. Vorticity at the right-hand corner,
in particular, is well contrained by data points. |