tag:blogger.com,1999:blog-7802716903254015310.post351207368555461380..comments2023-06-13T13:24:07.539+01:00Comments on Imperfect and Tense: To the power of fourImperfect and Tensehttp://www.blogger.com/profile/07348507012722069785noreply@blogger.comBlogger6125tag:blogger.com,1999:blog-7802716903254015310.post-10668906768686806122014-03-23T15:27:03.468+00:002014-03-23T15:27:03.468+00:00Martin, having looked at a few close-ups of the be...Martin, having looked at a few close-ups of the beach where I was photographing insects and molluscs, I'm going to back track on what it's made of. Possibly sand and shell. Or all shell. But not just sand. Sorry.Imperfect and Tensehttps://www.blogger.com/profile/07348507012722069785noreply@blogger.comtag:blogger.com,1999:blog-7802716903254015310.post-40749802630732422172014-03-23T10:31:14.575+00:002014-03-23T10:31:14.575+00:00All very interesting. I don't know if any of t...All very interesting. I don't know if any of the other barriers have a water pipe/bridge beneath them to allow the currents to continue. There appear to be beaches on either side of barrier 3, but not at the barrier and a possible long-term extension of the island between 2 and 3 towards the east in the form of downstream sand flats.<br />I suppose the other possibility is that if there is much in the way of wind-blown sand then the fourth barrier has gradually formed a sheltered place for it to be deposited. <br />The satellite image (Google maps) shows that there is plenty of sand within the bay of barrier 4 in addition to that at the barrier. Therefore it wouldn't take much in the way of swells to bring that in an enlarge the barrier now. Certainly there are other sandy beaches around for an exchange or movement of sediment.Martinhttps://www.blogger.com/profile/13798912100227844091noreply@blogger.comtag:blogger.com,1999:blog-7802716903254015310.post-45707431421333440982014-03-22T15:33:20.119+00:002014-03-22T15:33:20.119+00:00Martin, Only Barrier 4 has done this. And on the N...Martin, Only Barrier 4 has done this. And on the North Sea side. We've not seen any scrub succession yet, though the area is occasionally used for motor bike scrambling (and possibly a supply of sand?). It is definitely sand as opposed to shell, but I'll follow up on your suggestions to investigate further.Imperfect and Tensehttps://www.blogger.com/profile/07348507012722069785noreply@blogger.comtag:blogger.com,1999:blog-7802716903254015310.post-86270513612092978822014-03-22T11:51:22.004+00:002014-03-22T11:51:22.004+00:00Or visa versa. South Ronaldsay is bigger...
Fasci...Or visa versa. South Ronaldsay is bigger...<br /><br />Fascinating piece Graeme. So what is the rock-type of South Ron' or Muckle Burray? Could the sand be local erosion, or equally have just moved from the sides of the inlet up to the end. If not then you are looking at much further afield or from the seabed/local sandbanks. You might also be able to tell its origin by the grain size/colour. White shell sand versus eroded sandstone.<br /><br />Geography in action. Is this an isolated case, or have beaches formed and grown on each of the barriers? The absence of currents through the inlets would also suggest that the Scapa side is likely to have silted up a lot and also formed a shallower habitat, or more mudflats for birds.<br /><br />The next step in the classic beach succession is the form of willow carr, more terrestrial sediments, and maybe small scrub. Any signs of this yet?<br />(Maybe I should stop there!)Martinhttps://www.blogger.com/profile/13798912100227844091noreply@blogger.comtag:blogger.com,1999:blog-7802716903254015310.post-85075931876695811752014-03-20T22:09:02.341+00:002014-03-20T22:09:02.341+00:00Good question! I would say "No," because...Good question! I would say "No," because I can think of other islands joined to each other by a sand bar where each is considered separate, St Ninian's Isle off Shetland Mainland, for instance. Also, I think it would be very hard to convince the population of South Ronaldsay that they now live on Muckle Burray!Imperfect and Tensehttps://www.blogger.com/profile/07348507012722069785noreply@blogger.comtag:blogger.com,1999:blog-7802716903254015310.post-54322145980642843502014-03-20T21:46:22.259+00:002014-03-20T21:46:22.259+00:00Does the new strip of sand mean it's not a sep...Does the new strip of sand mean it's not a separate island anymore?Ruth Walkerhttps://www.blogger.com/profile/05268638591427597146noreply@blogger.com