 Thank you for inviting me to present at this meeting. The work that I am... that is contained in this talk is that of a number of people. So you can see the list of people on this slide and I've probably forgotten a few so apologies to them. What I want to look at is a summary of how combining interdisciplinary research can reveal clues to changes in sea level through time. So the North Sea Basin is an amazing natural archive that records the ongoing interplay between Iceland and Water a'r hyn o gwiswyddiad o'r hyn sy'n gwneud o'r cyflog sydd wedi'i raddlu gweld i'r ysgrifennu o'r gwneud o'r rai newid yn gyfanyddio'n gyfer Dogeland. Ydw i'r ysgrifennu hynny yn ymdweud yma sydd mae'r anologau modernd, sydd yn ystyried o ffyrdd ymgyrchu ymgyrch yn ymddangos, yn ymgyrch yn ymgyrch yn ymgyrch yn ymgyrch yn ymgyrch. Mae hyn yn gallu nhw'n ddataeth. Rhaid i'r rhaglen newyddau newydd yma yn gwybod, yn ysgol yw rhan o'r ffordd o'r gwaith ar y cyfnodau sydd ymgyrch. Rwy'n dwy'n gwybod Lluwis Tizard yn olygu'r rhaglen y gweithio ar y cyfrifodau ac yn y gweithio gweithio yn yr ysgol yma. Rwy'n go i'n gweithio i gyd i fynd yn ymgyrch ar y mawr, o'n gweithio ar eich cyfrifodau C4C. Mae'r ddweud ychydig ar fynd arfer. I'm going to be concentrating most of my talk on Doggw Bank, it's where I have been deeply involved for the last 12 years of my life, I sometimes feel like I'll never escape Doggw Bank, even by moving to the States. I also want to talk about sharing Ym Sholwn and Dungeon area, and then I'll just briefly touch on this area down just off the coast of the Netherlands as part of the Riser project. So the data that we generally work with comprises the geophysical, the geotechnical, which are these kind of wiggly lines down here, and the geological, and what we're trying to do is combine this with an understanding of geomorphology and environmental processes so that my job has previously been to unravel the processes that are going on and the impacts that they might have on the properties of the soils within the foundation zone. So to my first example, which is Doggw Bank, which is this isolated topographic high in its current stage that sits in the central to southern North Sea, and previously there was this line of question marks there of hippie dragons and no one quite knew where the ice went and what the ice had done, but we have had access through sometimes mind bending analysis of over 80,000 line kilometres of seismic data, both 2D and ultra high resolution 3D, and we've from this managed to identify a number of different environments that were present at some point over the last 25,000 years. We've got some of the images down here, you'll find quite a lot of my presentations have modern day analogs attached to them, and that's mainly because I found that geotechnical engineers find it really difficult to understand that this was predominantly a terrestrial landscape, it was a terrestrial environment and only recently in its life has it become marine. Now we always thought that Doggw Bank wasn't going to be the nice layer cage stratigraphy that the historical BGS data had proposed because that was based on two seismic lines that were spread over 10 kilometres apart from each other with an awful lot of expert interpolation going on, but the geology and the geophysics and the geotechnics indicated some weird and wonderful things were going on. So we have on the left here this seismic anomaly map, which seemed to immediately indicate to us that there was a river system or something very complex going on, but at multiple levels through the data. And then we have the geotechnics, and this graph here plots a worldwide offshore database that the Norwegian Geotechnical Institute have been collecting for over 30 years on the relationship between pre-consolidation stress of a soil and the undrained shear strength, so how strong is it. And this is what has come up and it shows a nice linear sort of representation. And this is Doggw Bank and it completely threw all of us and we didn't know what was really going on. So we started looking at sea level and this was a very, I apologise to everybody that works in sea level in far more detail than I do. This was a very rough and ready plot, again done for the benefit of engineers that we were working with who weren't geologists, didn't understand the geophysics, they were very geotechnically minded, very black and white in looking at things. This was to show them roughly what the sea level has done, roughly when ice might have covered the wind farm zone, but where land was specifically. And so you've got this long phase of tundra here, the Doggw Bank starts to build up around this time. This is the pre-Doggw Bank surface, the Emean surface. And it's not until around here that you actually get this shallow marine coming in. Now does that have an interplay on the strange geotechnical results that we were seeing? So this is one of our, one of the horizons that was taken out of, this is 2D data at 100m line spacing. And you can clearly see that there are still a lot of artefacts in here. It was a very quick pick. We had to produce this within three months and this was on about 50,000 line kilometres. So it was quite a quick and dirty first look. But you can see that there's a lot of fluvial channels in sizing here and we predict that it might have looked something like this. The sea level has dropped, you have glacial conditions further to the north, so you're entering this tundra kind of system. But you see this clearly braided fluvial system. And then I want to go on to these two little examples here and I'm just slotting this in now to try and really reinforce the case that this has to be into disciplinarity going on. So these are both surfaces here. This HO5 that is marked is a desiccation surface, what we think of a desiccation surface, and it bounds the lower doggah bank from the upper doggah bank. HO3 here is where you move into, we say, Holocene deposit, but it was actually, we think, deposited over a longer time span than the last 10,000 years. But we have no terminology yet in our lexicon offshore for deposits that are not glacially related, but are not also truly into the Holocene yet. They're in this transitionary period. And this is that scatterplot that I showed you. And this is what happens when you turn these data points and you divide them by this horizon, this very clear seismic acoustic response here, and you start to get still a lot of scatter in the lower doggah bank in this unit, but you start to get something that's resolving itself in this upper unit. But I'm putting this in here to show these are the geotechnical responses at the locations of the blue lines, and you can see our boundary is here, and that's a very little response here. This is from, she said just checking her notes, this is from the cone resistance. But actually, you move a few hundred metres away, and you do get a kick at this boundary. So by not including everything, you could be missing out on information that tells you something about a change, a change that is environmental, but not lithological. So we went into this in more detail. This was a map that was produced by Andy Emery, and I've got more of his work later on. He did some fantastic research into this area of doggah bank. But looking at this area here, we mapped out that horizon. We mapped out that 805 horizon. And what we're seeing is that we've got a glaciated landscapes. You've got these, the dark purple, our arcuate marine systems. You have basonal systems lying in here, and then you have these, where we propose meltwater drainage channels could be running. And these were backed up when we went into the seismic investigation of this. But moving to the east of this area. So this is a plot that shows the end of those arcuate marines coming through. But if you change all to the colour so that you're pulling out the detail in this area, you see that actually we've got a lack of stream unit here. We've got quite a big proglacial lake forming, and this area was very swampy. And this is the seismic through some of that. And you see these beautiful laminations, but there is disturbance. So we've got gas moving up through the system. So there's a lot of evidence of organic deposits far more than we saw over further west. And I want to concentrate on this tributary, this river channel running through here, which you can only just see on this horizon. But this is the work that Andy did and has published in 2020. He's still producing papers on his PhD, and it's some amazing data and analysis that he's done. And what you can see is this inside channel, if you do the interpretation to the seismic, you've got evidence of braid bars building up. You've got shallow marine infill. You can start to see which direction your sediment source is coming in from and how your channel infills are starting to alter and change. And then moving that out across a wider area, so this was the channel that we just looked at. We can actually now take the CPT information, so the geotechnical information from the same area, and you can start to pull out where is shallow marine, where is channel fill, where is it glacier tectonised, where have you got finding upward sequences, fine sequences. So the CPT information is giving us a lot more detailed information than the geophysics can give us because you have vertical resolution issues within the geophysics. And so it gives us more clues as to the relationship between the glacial landscape and rising sea levels as they're coming in and flooding and inundating this area. Now in this example, these are a couple of 3D seismic examples also from Dogger Bank, and it shows yet another step change in the vertical resolution that we're starting to get, that gives us an insight. So anything above this yellow line, these are our Holocene deposits, and you see that we're starting to pull out some differences in here. They're starting to be some clear surfaces coming through, but this is what we call fast processed ultra-high resolution seismic. So it hasn't been put through its full processing and these plots were generated to start giving us an idea of what we could be mapping to help with the foundation design. But you take the time and you full process it and you start getting these incredible images coming out and you can start to see here the detail of channel infills and where you've got different units coming in. And also combining with the geophysics what that indicates about the sediment and the grain size coming through here, but it's these kind of details that are now starting to indicate to us that we might have multiple phases of transgression coming through. It's almost like the sea sort of undulating slowly before it finally inundates. Backing this up was some work that was done by another PhD student, but right back at the start of this investigation in about 2012 and these are some fibrocores from this area. This is a deeply in size channel that has up to 30, 35 meters of sand infill now, but these were just for some BGS fibrocores and you can start to see that we think there's evidence there for multiple transgressive events before the sea level finally flooded over Dogabank. This was another BGS fibrocore and I will go into why a lot of my core data comes from BGS fibrocores at the end because it's the one sort of bugbear that I have with this whole working with industry, although we get access to multi-million pound surveys. These sea level points or these indicators that are used are from Shenan et al and this is an offshore sea level curve and what we see here is that we can actually pinpoint in the fibrocores here where we sit on the sea level curve at certain indicators and taking this one stage further. This was some work that was done for the form and consortium by Wessex Archaeology that showed again where some of our dates were plotting on the sea level curve. We have very few dates and a lot of the dates that we think have been disturbed, some of them appeared to be upside down in order, so we think that a lot of the material that we're looking at here because it was so radically scoured and tectonised by ice fronts moving backwards and forwards across the area, a lot of it has been disturbed and reworked and potentially is not in situ, which is why there is a bit of a question mark over some of the some of the dates from this area. But there are other things backing us up that this was an area where people could live that the sea didn't fully come in all at once from mammoth teeth and bones from neighbouring areas to work flint tools and also interestingly enough again on this left-hand side this plot here is some geotechnical data recovered that shows that there was ranges of salinities but that there was a presence of fresh water at all times through this environment. Again this is this is work that was done and we saw a lot of this yesterday so I'm not going to spend a lot of time on this except to say that Wessex Archaeology when they did this analysis found very similar indicators for localised bog or swamp freshwater marshlands and that occurred this specifically occurred in that area around that lakastrian environment. We haven't found evidence of things like this in the highly glacier tectonised area it seems like that activity and the process is happening there have removed a lot of the indicators a lot of the clues but in this lakastrian environment we have got these indicators here and again going back to this fibrocore you can see here a clear transition from foraminifora through to pollens and indicators of this these kind of plants being located in Doggobank in certain parts specifically around the sort of channel edges. So I just want to quickly step to sharing him Shole and Dutch and now hopefully to try and prove that Doggobank isn't an anomaly and that we can we can plot these same things all the way through so these are the areas that we're looking at these these were the original wind farm sites in here and these are the extension areas that we're now we now have data from to look at and I just want to go back to something produced by Claire Mellott that was published in 2019 and this was a look at across Dungeon and a look at the information that we can pull out here so you've got this glacier tectonised hill here you can get the direction of ice retreat but also the direction of thrusting through this this also goes back to the weather chalk and in places this was mentioned yesterday in one of the talks about how close to surface it came and in some places we have this weather chalk coming right up to surface so a lot of our information about about the more recent environments has actually been scoured away by these ice sheets but moving slightly north up into the Humber REC area and again this was a lot of work that was done by Dayton Dovert BGS in association with Vince and other people and we have we can pull out these kind of broad overviews I mean for us as geologists they're incredibly detailed but for people looking at sea level rise these aren't detailed enough you don't get the resolution but you start to get an idea of now where you're getting channeling the extent of the channeling and also how little in many cases holocene materials are still left to investigate and this is the seismic example through this area you can see that there are indications of things going on up in the surface but not enough detail so this is what we have been used to the Inamar data to show us channel generation to show us um yes sands beneath holocene deposits to show us the detail within the holocene deposits and unfortunately I think I've been spoiled by looking at the dog a bank data sets and the 3D data in this I now look at this and I throw my hands up in horror and go I can't possibly interpret so much detail in this but this is a lot of what we're getting there are um not that many at the moment um offshore developers who are prepared to go to the expense of 3D data to satisfy the geologists unfortunately and then finally into this site which is part of the riser project so this is being led by Natasha Barlow at Leeds with a huge team behind her and this is a wind farm area just off in the southern North Sea and we managed to piggyback onto a food grow vessel who were doing some work for the developer to actually take some calls through this site and we had used the offshore wind farm site survey data to indicate where we thought there were peats and what we were trying to do was catch the emion flooding surface up through here um and actually this has turned out incredibly well and a lot of analysis has now been done of these cores and we're now moving into a phase where we're looking at modelling and trying to model the sea level rise here so if we can get a really accurate picture here can we then expand it out to other areas and start to see what sea levels we're doing back in the transition from the emion or through the emion flooding surface so I would recommend going and looking at the riser site on Leeds University website for all the information about all the modelling and what we're starting to pull out of that so my conclusions are with the North Sea is a great location to look at the interplay of ice and sea and climate and that's a lot of what we're doing is showing that you may well not have a lithological change but you have got an environmental process change that affects the properties of the soils in some way in some manner so actually rather than just looking at it as a pure geologist and doing my stratigraphy looking at my lithology actually you need to go into more detail and start to question every unit where you know there have been a lot of environmental processes happening and it requires the integration of geoscience archaeology and modelling to really try and get a handle on what was happening with sea level the wealth of offshore data this is a really exciting time to work in this area as many other people have said but now we're coming on to my bugbear which is all of all of the information about what might be happening with water levels are teasers and they're qualitative because we don't have the dating to tie down when things were happening and a lot of the time this is down to how wind farm developers view geology they often don't think that geologists are important that everything can be decided on the geotechnical results and we are certainly bringing around the viewpoints of the developers we've worked with to understand this isn't true but they still place most of their emphasis on obtaining core material to develop it for geotechnical testing so a lot of the core material is destroyed and sometimes we're even lucky that we can get to log the cores before they're taken apart and destroyed and so we get these qualitative teasers but we can't quantify anything because we can't get the dates sometimes this is just down to the material has been reworked or eroded or isn't there or there's nothing in the material to date but quite often a lot of the material that we want to date like the peats are taken away for geotechnical testing and we can't get our hands on them and I think this is something that we that needs to be addressed as we move forward in working with industry in particular and accessing these data sets and that's me done. Carol thank you very much dead to time you spoil us there's a number of questions and comments coming in here oh goodness by the way I will just say that the point about the cores is incredibly well made the right from Claire Millet there's huge volumes of sand on Doga Bank that may bury archaeology where did this sand come from and why is there so much there there when compared to other parts of the North Sea. Wow and that is something that I really wish we knew the answer to and Claire if you've got any ideas on this we don't know I mean it tested with the with the direction of the ice movement we know that we've got over Doga Bank we've got this meeting of both Fennos Gandian ice at Claire's just saying no idea oh we've got the meeting these two ice sheets we've got the Fennos Gandian ice coming in and we can tell but that had a very big impact towards the early phases of Doga Bank being developed but then you have the British and Irish ice sheet coming in as well and you have this confluence zone and we think we've picked up where we have some of this so we've got ice coming from two directions but they are predominantly northerly directions from north west through to northeast so if you imagine that that that ice is decaying and you've got your ice front retreating and you've got the melt water coming with it that's bringing this sand into the system it has to be coming from the north but there are no obvious points in the north that we have seen in the thymetry or other investigations where you have got that amount of sand missing as it were where it could have been eroded up and then brought down with the melt water so actually that's still something that's very much a bit of a mystery to us I'm afraid. Thank you very much. From Richard Bates he asks whether you can use the higher resolution data to look at regional tectonic patterns of differential uplift. Again yes I think we could but again we have a bit of an issue with how much 3d data I mean the 3d data is incredible and we are actually imaging very in in one area on doggle banks some very deep seated faults that are coming up from about 200 meters depth that appear to be reactivated by the ice as it comes back over but the corridors that we're working with are the they generally tend to shoot the 3d seismic over the corridors where the turbines will be placed so I have very long corridors kilometers long corridors but they're 150 meters wide so you really need the good 2d seismic grid underneath to then start extrapolating out the detail that you're finding in the 3d seismic again this is the the problem with predominantly being you know most of my time was paid for by industry so I had to provide what the client wanted the client is happy for us to do as much science as we want using the data afterwards but it's then finding the time to fund doing that science that has been problematic but it's something that I think you could do yes with some carefully planned seismic surveys 3d surveys. Rob Nedwards thanks you for your talk to what extent are you confident that your record is showing sea level cycles as opposed to forced regression linked to changes in sediment supply and you're continuously rising the sea? I'm not at all confident to be honest and again a lot of that goes down to what we were looking at to try and pull some work you know some initial interpretations out so the viable cause that we have used are useful but they are old they have maybe not been stored in the optimum environment and so have themselves undergone a level of degradation so that immediately puts a higher higher band of unconfidence unconfidence that's not a word it reduces the confidence levels that we have in what we're pulling out again if we could if we could have got to the cause from that same area that were taken in the first survey on Doggobank and actually done a really detailed core logging exercise I think we might have been able to verify what we were actually seeing but we didn't get in in time for that I will caveat that with now saying that we are getting in in time to do work on the other areas of Doggobank with these cores and that they are letting a seller geologist offshore so that as soon as the cores come up they get locked and we get all the information that we need the detailed information but for that particular example I'm afraid I can't really say. We're going to have to move on to the next talk soon but I will just say Michael Grant's pointed out that you know there is a that the about the dating point and a lot of the other developers that he's involved with have produced extensive dating strategies and there are issues about curatorial oversight which I think is very fair and I think Jeff said in the first talk there are different attitudes towards responsibility in various areas so Michael makes a good point point there. There are questions coming up about the nature of geotechnical tests and scouring and and other issues of areas where data are held which I think I'm going to have to ask you to answer in the chat at this moment so I have to keep try to keep this of course.