Thursday, February 24, 2011

Playing in the Snow

While we were visiting our daughter and her family in Jersey City, NJ - for Christmas - we were gifted with the 6th heaviest snowfall in NYC history. The Jersey City-area received about 23 inches itself.

So after 2 - 3 days of playing with my grandson and faced with the beginnings of "cabin fever" (including issues with the wireless internet), I ventured out with my cameras.

The "dryness" of the snow and the almost-constant wind during and after the snowfall resulted in "sedimentary structures" and eolian, dune-like features (2nd photo) in the snow drifts.

The shifting wind directions and wind speeds interplayed with trees and artifical structures to produce a number of interesting scour and dune features analagous to what one might see at the leading edge of a dune field, prior to obstructions being totally covered by the advancing, fine-grained sand.

In all of the photos, except the second one, the wind erosion has revealed the (layered) stratification of the snow. As in the case of bedding planes in layered sediments and sedimentary rocks, the revealed layers suggest a brief cessation of deposition during the snowfall (perhaps due to increased wind gusts), when there was a slight consolidation (freezing) of the exposed snow surface, which was then followed by another round of snow deposition.

If this snow had fallen at a slightly-higher temperature and without the wind interaction, these "sedimentary structures" would not have been formed, nor preserved. Other deposition and erosion analogies could be applied in this setting, comparing the contrasting the effects of water and wind in shaping short-term and long-term landforms, both large and small.

No comments:

Post a Comment