Monthly Archives: December 2012

ice flowing from off to onshore on west coast of Ireland?

This is a recurrent theme. Was there enough nourishment of ice on the shelf such that flow could be directed shorewards? I have come across this a number of times and have wondered.

James raised it recently in an email and with a Colm reply, which i reproduce below;

”On another but related issue, Roland Gehrels was also at the meeting. He interestingly mentioned that years ago, when he was a student in Maine, Harold Borns gave a seminar on ice flow directions in Connemara, suggesting that the striae had been misinterpreted and that the ice was flowing from the shelf onto land. I’ve found an abstract on his website:

Borns H.W., Jr., and Warren, W.P. , 1990, New Evidence for Ice-Flow Directions over Connemara, Ireland (Abst.) Abstract Volume of †Connemara, 1990″ conf., Unin. College, Galway, Ireland.

This may well be a load of bollocks but I thought it might be worth mentioning. I’d be interested in Colm’s response to this.

Cheers,

James”

Hi James,
Pretty grey literature this as the conference that the abstract relates to is not properly listed! I have had a quick search but did not find it. I see Willie Warren is the co-author. I remember being at the Drumlin Symposium in Coleraine in 1992 and Willie giving a talk which mentioned this idea of ice flow out of clew bay and on shore – so that may be what the abstract is referring to. It did not go down well with the audience as I remember although admittedely it is a long time ago now. I have seen nothing further to the south of Clew Bay in Connemara or Clare that shows ice flow onshore but of course that is not to say it is not possible.
Colm.

I just went trawling through Sarah Greenwood’s thesis and found some more support by Warren and also by Jordan. see below (Sarah maybe you want to comment some more, I seem to remember us puzzling over some flow sets?);
”Warren’s reprisal (1992; Warren and Ashley, 1994) of Close’s ice sheet model (Figure 2.1c)
goes further than simply suggesting Connemara was a primary ice centre, but rather depicts an
extensive Connemara ice divide stretching from the Slieve Aughtys, across Connemara, Clew
Bay and into the Nephin Beg range in North Mayo. Under this model, Warren describes
onshore ice movement through Clew Bay, an idea which has received some limited support
from Jordan (2002).” p13-14

This keeps coming up and if I add it to Sara Benneti’s comments about glacial evidence way out on the Porcubine sea bight, it all sounds rather interesting. I think we should keep an open mind and also take some active looking

Chris

Chris helps the Yorskhire Post make sense of the latest sea level paper re ice sheets and a possible link to the latest flooding

article by Chris Bond;
http://www.yorkshirepost.co.uk/news/features/why-antarctica-meltdown-may-mean-more-floods-for-us-1-5183666

We should remember to contact Chris Bond, he seemed very keen on profiling our project at a later date

New paper in Science reports that glaciologists using different methods now agree that warming is melting the world rapidly and conclude the ice sheets have contyrived 12 mm to rise of sea level since 1992 12 mm

..or more precisely, as reported in the Shepard et al paper 2012;

We combined an ensemble of satellite altimetry, interferometry, and gravimetry data sets using common geographical regions, time intervals, and models of surface mass balance and glacial isostatic adjustment to estimate the mass balance of Earth’s polar ice sheets. We find that there is good agreement between different satellite methods–especially in Greenland and West Antarctica–and that combining satellite data sets leads to greater certainty. Between 1992 and 2011, the ice sheets of Greenland, East Antarctica, West Antarctica, and the Antarctic Peninsula changed in mass by -142 ± 49, +14 ± 43, -65 ± 26, and -20 ± 14 gigatonnes year(-1), respectively. Since 1992, the polar ice sheets have contributed, on average, 0.59 ± 0.20 millimeter year(-1) to the rate of global sea-level rise.

Chris gave the LQL, no 90 on our project

Chris delivered the 90th London Quaternary Lecture, hosted by the University of London; ‘The BRITICE-CHRONO project and it’s role in forecasting deglaciation of polar ice sheets’ in Nov 2012. Turned out to be a very nice occasion and with wine thrown in and a great talk on how bloody hard it is to get good records of Eemian ice from Greenland ice core records – by Sune Rasmussen.

Had very useful chat with John Lowe, who had some ideas of targets we could usefully date (more on this later). He was also very supportive of our project.

Only my 2nd visit to Royal Holloway

Bespoke GIS per transect nearly ready

The BC onshore GIS is near completion, and will be available for transect leaders in early January. It includes: OS and geology maps, coarse and fine resolution DEMs, mapped glacial landforms, a postulated retreat pattern, the location and information on currently obtained dates, palaeo-tidal ranges and amplitudes, palaeocoastlines and the location of BGS cores with hyper-links to their scans. Offshore information will be incorporated at a later date.

Should we try and use field-based XRF scanning to help link lithologies onshore with those offshore?

Although not funded by BC, Sheffield has just bought a hand held XRF scanner. The possibility arises that this might be of use of for terrestrial parts of transects to help in linking lithologies with our cores on the shelf and the already Itrax-scanned cores further offshore. Get in touch with Mark Bateman (m.d.bateman@sheffield.ac.uk) if you can think of sensible avenues. Is it worth taking it on the cruises for onboard scanning of cores?