Another computer model

 

There is a new and rather spectacular computer generated interactive and animated "icemap" showing the expansion and contraction of the BIIS and the SIS during the Late Devensian. It's free for anybody to use, and it has been created by Henry Patton at Tromsø University in Norway.

https://icemap.rhewlif.xyz/?fbclid=IwZXh0bgNhZW0CMTAAAR3Q2Wsw4JAYdL_lyda1ajOdLQNbtwJ8iePNU34H-v__H4qAlL_yK383hTU_aem_ASWAPezhTzxON2vIelI668jcP7phW4y9poLVfj70C2jDTe9HnYeSPFfM1VL010AJ1AuLrKH2LHk726z2Byo50Qfa#

It's visually very attractive and seems to me to be pretty reliable for the most part. However, there is a major issue with dating, and the peak of the LGM is shown here as around 22,500 yrs BP as compared with around 26,000 yrs BP in the BRITICE reconstruction. Who is correct? This is a very substantial difference, no doubt explained by differences in the calibration of radiocarbon and marine isotope dating........

Also, Henry seems to have been using different databases for different parts of this computer programming exercise. On the ice extent map, the Devensian ice edge is shown hitting Salisbury Plain. That will cause quite a lot of discussion, since the BRITICE reconstruction is far different -- and with most researchers suggesting that the inner part of the Bristol Channel was not affected by glacier ice during the LGM, but that ice extent was greater during earlier glacial episodes.

Also, on the map showing actual LGM ice limits, the line used by Henry is very unreliable, being based on an acceptance of the "ice free corridor" in central and south Pembrokeshire -- which I demonstrated as being unreliable theoretically and in practice, in my 2023 QN article.

But all in all a very worthwhile and attractive teaching aid which will fascinate a new generation of budding glaciologists!

The LGM maximum line as shown on the new model.  The representation of the Bristol Channel as being effectively ice-free does not stand up to scrutiny.