After spending much time at my ice wedges in Adventdalen on Svalbard 78 ° N in winter time 07/08 and 09, I finally could get to know them this summer! To be honest, the only thing I have really seen before from them was a little of their surface topography (covered in snow) and some of their cracks, but enough for me to fall in love...

A DAAD scholarship in my backpack and many ideas what I could do in six weeks of fieldwork for my thesis, I travelled to Longyearbyen this July together with my little son Kai and his grandma (1000 thanks!). 

The great fact of polar day is very useful, you can work at day time and don´t stop at night. Especially due to strict rules for any digging activity, it is not aloud to leave soil pits opened (saving small fat Svalbard reindeer from walking into a trap.).

But maybe you ask yourself now what did I do there... ? I focus on ice wedges that form syngenetic in a surface that receives aeolian material from the large braided river system. I digged many holes and cliff sections to study the sediments above ice wedges and in the centre of polygons and took two permafrost cores from an active and inactive site for later analysis. Together with the cliff stratigraphy I try to get 

1. some more puzzle pieces about the Holocene ice wedge formation history in Adventdalen and 

2. understand the different characteristics of ice wedge networks within a very small area.  You can find different polygon pattern and morphology and recently active and dorment ice wedges within a few km distance at some m above sea level.  

 So, What did I found out?

First of all I am proud to say: I saw them, I touched them, up to 3 m thick ice wedges! And it was a surprise for me, that I even found them at a site where the surface topography is more or less flat. Even more surprising they occured at the permafrost table and make me wonder because it means, either my surface is not aggradational, or the ice wedges are recently active even if it looks different from what I know, or the ice wedge (1 m wide) formed in the Little Ice Age or earlier and the recent sedimentation rate is very low, or something completely else....

The relative sea level in my study area fell until about 4000 years BP therfore any periglacial landform must be younger. In my lower cliff section I found thick organic layers which can be traced for several 10s of meters a long the river cliff. Whithin the peat layer there was a destinct, several cm thick segerated ice layer vertically uplifted by a growing ice wedge. So far I infer this ice layer do be formed before ice wedge formation started at this particular point. It may be one puzzle piece that supports the idea that ice wegde formation started delayed after nearshore terrestrial sedimentation. But nonetheless, the occurrence of a thick segragated ice layer in the lower part of the cliff indicates early permafrost conditions...

I realised that the type of sediment (mineral vs. peat) and vegetation cover can be very different from site to site, also moisture content, active layer depth and therefore thermal regime. Small differences in morphology and drainage may be very important for the dynamics of each site.  But over all - like it should be - there is even more I do not understand and my ideas move in my head like at a rollercoaster.

My thesis still has to be written but I hope to present you all my results at EUCOP! :)

Steffi

P.S.: I wouldnt have managed all this without the great help of several UNIS students and staff THANK YOU!

PPS: For people living in Leipzig: I will do a presentation about my thesis (Formation and dynamics of Holocene ice wedge polygons in Adventdalen, Svalbard) in an open seminar at the 17th of Nov. 2009 at the Institute for Geography, Johannisallee 19 A, 04103 Leipzig, Germany

at 17.15 h.