Dust flux, Vostok ice core

Dust flux, Vostok ice core
Two dimensional phase space reconstruction of dust flux from the Vostok core over the period 186-4 ka using the time derivative method. Dust flux on the x-axis, rate of change is on the y-axis. From Gipp (2001).

Saturday, April 9, 2011

A little more on rhomboidal rills

Spent a pleasant day on Axim beach watching the rhomboidal rills form while at sea Ivoiran refugees streamed eastward.

The beforms on this particular beach are not as impressive as the last time, due to the lack of black/purple heavy minerals. In these forms the sorting is mainly seen in variations in grain size.

No scale. My bad. The largest features are about 20 cm in length.

The more detailed view above shows one of the larger rhomboidal rills left of centre breaking up into many smaller features.

Bandwidth won't allow any of the films to be posted just now, but one thing that has become clear is that even after the wave has receded, there is a very slow flow of coarse light grains down the edges of the rills.

Self-organization in the flow showed up well in the photo below.

Self-organized branching flows during wave recession.

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