The Spitsbergen-Svalbard.com Eas­ter brain­teaser – what does the pho­to at the bot­tom show? – has got a lot of nice repli­es. A sel­ec­tion of ans­wers (my own trans­la­ti­on of tho­se that were sent in Ger­man):

• Clo­se-up of Hump­back wha­le skin
• Clo­se-up of Wal­rus skin in black & white
• Ice sur­face. It looks like some­thing has ground it (like the sur­face at a cur­ling court (Swe­den beco­me world champs yes­ter­day!)). So that has to be my guess. Not a cur­ling court, but a ice cover­ed sur­face that been groun­ded in some way. May­be from dog sledge skids?
• Ice struc­tures
• Is it fro­zen water from below with trap­ped air bubbles?
• A warm item (e.g. a warm kett­le) put on fro­zen water.
• An aeri­al pho­to of fro­zen mud flats at low tide.
• I thought fro­zen water at first, but I don’t think that’s right.
• Not polished con­cre­te?
• Iced-over stroma­to­li­thes that got a gla­cio­lo­gi­cal hair­cut
• Nega­ti­ve imprint of a fos­sil fern
• think it is water over some fro­zen soil or some­thing….
  actual­ly i have no clue even after sta­ring for 30 minu­tes at the pic­tu­re!
  in any case: it is beau­tiful! 🙂
• A true con­ch in shal­low water?
• May­be a shoe sole
• A rather rare iron struc­tu­re on a geo­de (or part of it)
• Pro­fi­le of a snow mobi­le belt
• Clo­se-up of ice struc­tu­re
• A dog in a river bed / ice sur­face

A num­ber of inte­res­t­ing and sur­pri­sin­gly varied ans­wers! It seems to have been more dif­fi­cult than I had thought, and this shows how much came­ra and lens may help to see things that other­wi­se are hid­den or that we see, if at all, in a dif­fe­rent way. All tho­se who have seen gla­cier ice have had this phe­no­me­non near them (but not neces­s­a­ri­ly seen it and paid atten­ti­on to it).

This is how the pic­tu­re was taken:

A macro pho­to of gla­cier ice in an ice cave in a gla­cier, with tri­pod and macro lens, to make smal­lest details visi­ble. The brain­teaser pho­to shows very small air bubbles in gla­cier ice. The indi­vi­du­al bubbles and chan­nels are smal­ler than 1 mm. The area shown on the pho­to is, in rea­li­ty, an esti­ma­ted 4×6 mm lar­ge, or rather: small. This net­work of air bubbles was ori­en­ted in a plain par­al­lel to the very clear ice sur­face, about 2-3 cm deep in the ice, which altog­e­ther made it pos­si­ble to pho­to­graph it. Plea­se don’t ask me how exact­ly this pat­tern of air chan­nels comes into exis­tence, I don’t know. Plea­se tell me if you know.

The first pri­ce for “Clo­se-up of ice struc­tu­re” goes to Ste­pha­nie in Scot­land! Ste­pha­nie, the choice is yours!

The second pri­ce goes to Leip­zig and the third one to Swe­den. Con­gra­tu­la­ti­ons to all win­ners and a big thanks to all who sent their ans­wers! It was fun, and that was the who­le pur­po­se of it.