How much do we know about Stonehenge? Less than we think. And what has Stonehenge got to do with the Ice Age? More than we might think. This blog is mostly devoted to the problems of where the Stonehenge bluestones came from, and how they got from their source areas to the monument. Now and then I will muse on related Stonehenge topics which have an Ice Age dimension...
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Thursday, 19 October 2017
Lambert Glacier -- a thing of beauty
There are few things on this planet more impressive than a big glacier in full flow. This is the Lambert Glacier in Antarctica. It flows into the Amery Ice Shelf. Click to see the image enlarged.
At the base of this NASA image, it is about 30 km wide, but at the big confluence with Fisher Glacier it is about 60 km wide. Across most of the area shown in the image, the glacier velocity is between 500 m and 800 m per year, but the velocity speeds up as the ice gets towards the ice shelf, with a flow rate of c 1 km per year. Surging glaciers sometimes move faster than that, but this is assumed to be the fastest-flowing big outlet glacier on the planet.
The streamlines or flowlines are shown here in extraordinary detail.
Here is another image -- this time from Google earth. You can see many of the same features.
Nunataks! I thought of the word and I was right when I looked it up.
ReplyDeleteWhat are the things on the surface between the 'L' of Lambert and the Mawson Escarpement? Are they small rock outcrops or lumps of ice on the surface of the glacier, or maybe even hole in the glacier?
Dave
Yes, nunataks all over the place! That area you refer to looks to me like an area of thin ice -- if you look you can see the surface undulations, similar to that which you see sometimes on ice caps or inundated uplands. I don't think there are any ablation or meltwater pits just there -- maybe just areas where hill summits are almost breaking the surface.
ReplyDeleteNunataks!
ReplyDeleteBelieve it or not, it is true I have discussed nunataks over coffee after a Service at Trowbridge Parish Church. The reason being (if you ever needed a reason) that the Church had recently welcomed into its congregation a retired minister, who had been vicar of an Inuit town on the Arctic Ocean coast, within Canada's Diocese of the Arctic - one of the largest Anglican Dioceses in the world.
There are possible remnants of nunataks in West Wales, are there not?
Tony -- Strange -- acc to my computer it was posted, but somehow disappeared into the ether....
ReplyDeleteAnyway, plenty of nunataks in Arctic Canada -- and there were some in Pembs as well. Try putting "nunatak" into the search box....
Yeah, I knew we'd mentioned them. Perhaps someone, such as you, should take MPP & his Merry Men/Women on a field trip next September? Or Peter Dunn, who comments on here, and has done artistic reconstructions of Stonehenge etc for the Stonehenge Riverside Boys & Girls. A bit of glacial geomorphology identification to assist with their imaginative ideas?
ReplyDeleteGlaciation so often seems to be the Elephant in the Room at least for these particular archaeologists.....
"Some nunataks in Pembs as well"........such as CarnIngli, on Brian's doorstep! (he has a Post on it).
ReplyDeleteI have also discussed pingos - circular raised features - with my retired Arctic Minister friend (Durham University graduate).
ReplyDeleteVery interesting Post or two on the Blog, e.g:-
25th April 2015 Pingos/ Circular Enclosures in Cardiganshire
Yes, pingos, nunataks etc -- they are all on the blog somewhere. That;s one reason why we get so many hits on this blog site-- things keep on coming up when students from all over the world do google searches.
ReplyDelete