 So I guess my title's been said, and thanks very much for inviting me to speak here. Let's see. Can everyone hear me? All right? Yes? Okay. Okay, good. So what I'm going to be talking about is investigating the feedbacks between deeper Earth geophysical processes, especially flexuralisosacy, and in that way linking the lithosphere and the mantle to what's going on on the Earth's surface. So I created this pyramid of the particular scientific approach I'm taking. And we have a topography on the top, and that interacts with surface processes, as we probably all know here, because topography tells us what kind of style and what rates of landscape evolution, landscape change, and depositional change happen. And that feeds back into the topography, and that's one big loop. Topography also acts as a surface load on the lithosphere and mantle, and that surface load changes the topography as well over a wavelength that's set by the lithospheric elastic properties. So I'm going to start in by talking about flexuralisosacy, in particular just a background on isostatic response to loading and some of the modeling work I've done. And that's going to be the start, and we're going to hit L to all the other points in this diagram later on. So isosacy, we have some sort of loads in the middle. Those loads cause a broad down warping of the lithosphere, or if we remove things, you'd see a up warping. That's because as the loads push down, they cause the mantle to viscoelasticly get out of the way, and the loads though don't necessarily, as you would think of it in a classic isostatic buoyancy sense, just push down locally. They actually act over a broader area determined by the stiffness of the lithosphere and the wavelength over which it bends. So these are a few model results from the one-dimensional version of the isostatic model I wrote. And so the green dashed line is the initial load in mantle equivalent density, just to keep everything as equal thicknesses. The black line is lithospheric deflection, and the green line is the final surface expression of that load. So as you can see if we have a really floppy one kilometer thick lithosphere, it acts basically as this classic area of predisosacy case in which we just flatten everything out by perfectly compensating locally. But as we go to the upper left here, or upper right, we have some strength of the lithosphere, and that causes a broader isostatic compensation, and as we continue to increase the lithospheric strength, that causes the compensation to be even more non-localized. So let's put on an imaginary load like this little sketch volcano, because a volcano is really, it's just bringing magma up that erupts as lava that covers some sort of surface, builds up into a roughly conical shape and acts as a nice point source of mass on the earth's surface. And that can be something that bends down the lithosphere. And we actually do see that. So this is the cover of Tony Watts' book, Isosacy and Flexural of the Lithosphere. And on the cover there is the Hawaiian Emperor Seamount chain, and around each of these volcanoes, you see a nice little flexural moat, and that's just caused by the weight of the lava on the surface. So we observe it, we have theory to describe it. I am not going to be going into any of the theory or the solution techniques due to time constraints, but we can talk about that later in any case. So this is a numerical solution of lithospheric flexure. A lithosphere that goes basically from being fairly floppy on the lower left being fairly stiff and rigid on the upper right. And as you can see, if I have these two bars up here that act as some sort of synthetic load, I have a very different isostatic response in terms of the flexural of the surface that occurs in response to those. In particular, where we have the lithosphere, we have a much stronger localized response, much deeper isostatic component. So I guess the main point of the slide is just that I've made this model, the model works, and now let's move on to looking at surface processes. And what I'm doing for that is working with Greg Tucker with his model child. A child is a great model to couple to other things just because it does pretty much everything. I mean, that's sort of hyperbole, right? It doesn't do deltaic deposition like said flex would in a couple other things, but it can handle a lot. And Greg Tucker has actually been very helpful and been a big proponent of pushing this work forward. So that's the other reason that we're local together. So there's this model, it's written in C++, my model is written in Python, and that's one of the great places where CSCMS can help us bring these models together under a consistent coherent framework. But I'm going to talk about that in just a little bit. First, we have a topography. We know a child can handle topography as well, and we have to think about what goes back and forth, though, between isoscecy and topographic elevations. So I'll bring you back to the diagram I had on the first slide. And here I have a bunch of different geological things. The blue ones are going to be loads that push the lithosphere down. The red ones are going to be removal of loads, negative loads. And the purple ones are the ones that can go either way. So mountain building, as we bring big crustal loads, thrust sheets on the surface, they push the topography down. That creates these flexural four of the basins around them in which we have sediment that further acts as a load. But that sediment has to come from somewhere, and that's from the mountain range. So as the mountains erode, that sediment is transported, deposited in that basin, also deposited offshore in deltaic settings. And as climate changes, we have sea level and glacial fluctuations, and those changes can work in either way to add or remove loads and cause isocetic responses. So there's quite a bit of application, I would say, of looking at the crustal lithosphere in coupling with what's going on on the Earth's surface. So what this looks like when we start to use it on the computer on the beach, the CSDMS supercomputer, is this. We have a model child, a model with my flexure component, and those are both linked in through one main driver that hands things off from one to another. And with those wires, it looks fairly like my little conceptual pyramid tilted slightly with child-handling surface processes and topography. And these arrows here, between that and flexural isocetic being represented by the wires going towards the driver and over to the flexure code. So we know that these things can talk to each other. That's great. We got it working. And so I'm just going to go straight on to a couple of examples. And the first example is going to be looking at the development of a Forland basin as we build up a just very schematic block-mountain range. And unfortunately, Apple computers never liked me all that much, so I've got to go out of this. And there we are. And so here we have it. We're going to have uplift on the left and that red section. And the top part is no isoscecy. The bottom part has a flexural isosce going on. So we can see there's a fairly different surface morphology developing. There's actually something in the artifact as the center of that block subsides because I have no load boundary conditions on the side. That big river is able to tap into the middle and build a large delta. Later on though, because that delta is prograding out, it lowers those regional slopes. And so coming in here, we see the drainage basin being cut into from the side. I'll play that one more time. This is a two-dimensional flexure of a plate. And so if it were one-dimensional flexure, it would have been symmetrical across that whole domain. But since it's two-dimensional, I haven't mirrored any of the boundary conditions. That's why we have that little bowl in the middle. And that might not be the most realistic, but it does a good job illustrating a simple coupling among the models. So just showing it to you guys again. We have that prograding delta there as it's tapping into the interior. And that is filling up that flexural basin that we're creating in front of our single block uplift mountain range. Back to the top part of it. And just to kind of get a schematic view, if we look from the side with no isotocyte, we have that just block shape with that linear to slightly concave up fluvial transport and depositional surface on the right. But then once you include flexural isotocyte, we actually have a full sedimentary basin looking thing in front of it. So that's kind of nice, because it means that we can start to think about depositional processes and growth-threaded depositional and other things that we can use to compare these models with data. The second example I have is erosional isostatic unloading of old decay mountain ranges. So mountain range uplifts you have a bunch of high topography. And as the roads, isostatic response causes continued uplift and rejuvenation of that range and extends its lifetime and the time in which it has significant relief. So here we are actually in a positive go back. So just to tell you what's going on, we have the same thing, a block on the left, except the block's already there. It's not growing. And we have rivers cutting back into it. We also have no load boundary conditions on the side. So this is like a mountain range that is short compared to flexural isostatic wavelength. So no isotocyte on the top, isotocyte on the bottom. You can see that we're warping that whole range up and from the color bar we actually are maintaining quite a bit more topography and relief. So I'll just let it kind of run through as you look at it. But there's a fairly different signature and something else that's evolving is this curved mountain front shape compared to a linear shape over there. So I'll play that one more time and just so the session moderates know this is about it. And it's kind of cool to watch the peaks stay high and the removal of mass there to steepen the pediments and to create much higher sub-submit surfaces. So these are just sort of a couple toy examples of this coupling, but we think they're kind of neat. And if we look at that final time step, we have, as I mentioned, there's this curved shape. And just thinking about this and other mountain ranges that have been technically fairly quiescent and have a fairly short length scale. If we look at the black hills, that also has this curved profile, whether that's due to erosion and isotocyte, I'm not sure, but I thought that was kind of a need as a possible target to try to model it with this approach. So the last slide, everyone kept telling me I was a guinea pig because really I'm one of the people outside of CSDMS, one of a few who's been trying to couple these models together. And actually it was kind of painful at times. Things kept getting reconfigured. I had to keep doing everything by hand. But CSDMS staff have been working very, very hard and you're probably going to hear this in posters to make this process a lot more painless. So this was fun. We got to see what happens when you couple lithospheric and surface processes, and they would all tell you that you should do this too. All right, thank you.