 Thanks everyone for joining us. Good afternoon and welcome to sharing Geoscience online. This year's virtual annual meeting of the European Geosciences Union. This year we have more than 18,000 abstracts and have already had more than 19,000 unique users from around the world participating in our events. I'm Terry Cook. I'm EG's head of media communications and outreach and I'll be hosting this week's press conferences and that will include a question-and-answer period following the presentations of today's four speakers. This is the first time we've ever tried completely remote press conferences before and so we may experience some technical difficulties. If the platform suddenly quits during the middle of the press conference, I'll restart it and give everyone about five minutes to rejoin the session. And if I'm not able to do that because of internet problems, then we will finish the recording and still post it to EG's YouTube video page. Also the transitions sometimes are a little bit slow and so I ask for your patience while we test this new greener way of holding Geoscience press briefings. Journalists, after the speakers have finished and you want to ask questions, please only use the Q&A function in Zoom to ask them. Do not use the chat or the hand-raising function. Also wanted to let you know that the abstracts and other documents relating to the press conferences are uploaded to the document section of the media website and that's media.egu.eu and so please check there for more information. I'm going to introduce all four panelists now to make for faster transitions and this press conference is titled Journey to the Center of the Earth and it's motivated by Jules Verne's classic novel. In it, the characters take an amazing trip through the planet's interior where they witness battling prehistoric creatures and have many more adventures before returning to the surface by an eruption of Italy's Stromboli volcano which erupted again last year. So the speakers who will take us on an equally exciting journey today are Malcolm Hart, who's an emeritus professor in the School of Geography, Earth, and Environmental Sciences at the University of Plymouth, and of all the CNRS Research Director at the University of Paris, Saclay, Paola Colemire, Royal Society University Research Fellow in the Department of Earth Sciences at Royal Holloway University of London, and Filippo Zanziboni, Senior Assistant Professor in the Department of Physics and Astronomy at the University of Bologna. So I'll now hand things over to them and then at the end I will open up the floor for questions after everyone has finished presenting. Thanks so much. Right, am I live with everyone? Yes you are, we can see your screen, thank you. Okay, as Terry indicated I'm an emeritus professor, which means I retired about 10 years ago, and my research in particular is micro paleontology, which of course is not really what this presentation is about. I've worked in all parts of the world and done some strange things with microfossils, like direct the route of the building of the channel tunnel between England and France, which is not something you normally associate with microfossils. But about 20 years ago a group of us got together to try and establish a World Heritage Site on the Dorset Coast, and this is now recognised as by UNESCO as a World Heritage Site, with outstanding universal value, and part of that universal value is that it records about 185 million years of Earth history along a 100 mile coastline. It's a place where lots of science began, and in particular it records a detailed record of Mesozoic life on Earth, and ever since the days of Marianning back in about 1810 collectors, scientists, geologists of all nationalities have been finding fossils in that coastline, and many of these would come under the geological title of Lagerstatten, in other words, exceptional preservation, and you can see why just looking at that first picture, somebody who works on microfossils would get excited at the sort of quality of preservation of that particular squid like Keflipod. The reason why I got involved was that all along the coastline we process samples for microfossils, and we find all these hooks, and for many years we really didn't know where these hooks were coming from, but now we do, and you can see in the bottom right hand corner there the arms of this squid are covered in paired hooks, and this is clearly what the animal used to grasp its prey. Now these squid are peculiar fossils, they're soft-bodied, so all we know is a very few records of the hooks, and the ear bones, the bouncing organs that these things had so they could swim in the water. That's a completely different story, but what we've been looking at is this area around Lime Regis. It's really interesting that Mary Anning, who's pictured there, collected fossils from these cliffs, and of course in the area near Church Cliffs, in the area with the red box, they excavated, and the trouble is the cliffs are now falling down largely because of the excavations, but we can't blame Mary Anning for that. But these are just some of the exceptional preservation of fossils that we find, and in the middle of that top specimen, and also in the lower one, you can actually see the ink sac, because these animals had ink sacs like modern octopus, and that was a defense mechanism, and you can still see the black ink within that specimen. Now this specimen was found last year, and of course one of the problems we have in a World Heritage Site is fossil collecting, and it's supposed to be monitored, it's supposed to be not controlled, but we have to be very careful that people just don't take parts of the World Heritage Site away. Of course the main thing is that because it's a coastline, what we find is that what might be in the cliff today after a bad night's weather could be in the sea, and some people would argue that collecting the fossils actually does science a service. But this specimen has been hidden away, but I've managed to persuade my co-author that really the beautiful preservation of the arms and the jaw mechanism and the hooks in the arms is something really quite exciting. And then we found this specimen. This specimen has been, I think, buried in a draw since 1879. To the left you can see the ink sac, but to the right in the top part of the diagram you can see the presence of a fish by the scales, and if you look at the bottom there you can see the scales, you can see the fins, you can see the head area, and you can see by the lines of hooks that this fish is being held by the squid, and when we look at the head area all the bones have been broken. Now I know there is a cliff above this specimen, and therefore it could be compaction, but the answer is that these bones in the head of the fish have been literally sliced through. So this looks like a violent attack by this squid-like predator, and as such it's one of the earliest paleobiological examples of a squid fish predation in the geological record. We do have older specimens that are known from collections, and here's another one. It's geologically younger, but you can see there's a fish being held with its fins visible, but this is slightly younger. So the one that we've been describing in this paper is literally extending the record of squid fish predation right back through the geological record to the base of the Jurassic, and this sort of paleobiology is what the World Heritage site is really all about, and this is now being described. We can't do much chemistry with it because the earlier collectors often painted their specimens with preservatives, or what they thought were preservatives, which of course does no good to modern geochemistry. So we literally have to look and not touch the specimen, but anyway that is the specimen, and it's part of a record of these interactions between some of the fossils that we find all along the Jurassic part of the World Heritage site. Anyway, that is the subject of this presentation and the paper that's going to be published in the next two or three weeks. Thank you very much. The next speaker will be Anne Devalpe. Hello. So I'm a physicist and I'm working on mental convection using laboratory experiments. Here I'm trying to get my slides moving. Yes, okay. So the evolution of our planet is completely conditioned by its cooling. So it formed hot in a cold universe, and so the whole evolution is going to be controlled by motion in the most viscous envelope, the mantle, and by thermal convection. So for a long time, since the early 30s, the vision was that you will have a large convective cells. As we got more observation, more data, this vision has changed. So we know now that there is plate tectonics with a number of plates that are moving along each other and that the deformation is very localized on the plate boundaries. Then when we look at the internal structure, that for example seismology is giving us a lot of observation about that, we see that the cold plates that are coming down in the mantle are delimiting two mental domains that appear a lot hotter, and they've been named LLSVPs, so large low velocity provinces. Those two domains also host most of the hotspots on Earth. And when with the more recent images by tomography, people have been able to probe those low velocity provinces. They've seen that it's hosting a number of large features and even that you can even say plumes, but those plumes are much fatter than what had been proposed by classical thermal convection. So there is a whole lot of new data that we have to understand in the framework of thermal convection in the mantle. So what we're going to do is not to get a miniature Earth in the laboratory, but really to look at the physics of the processes to be able to provide a quantitative framework to predict and interpret the geological observation. So what we do in the laboratory is to take typically a fish tank, and we're looking convection, so hot heating from below, cooling from above, and this fish tank is filled with different fluids that have different flowing properties. So we can really isolate a phenomenon, a convective phenomenon. We can control and characterize all the boundary conditions and all the motion inside the tank. And so we have a good data set on which we can get a real physical understanding and physical laws to explain our observation. So what is varied systematically are the fluid properties and also the boundary condition. So then with those physical laws we are able to interpolate the result to the Earth's mantle. And so for more than a century now people have known that the convective intensity and the convection patterns depend very strongly on the temperature gradient, so that is going to get the buoyancy forces, the engine of motion, and the fluid viscosity. So if you have a low convective intensity you're going to have mostly cellular convection. But when the convective intensity is large enough, so a large temperature gradient, low viscosity, like in the mantle, then you can get plumes, hot plumes that are developing from the hot boundary, and you will have cold plumes from the cold boundary. So this is explaining really well how you could get hotspot from mantle plumes, but on the other hand it gives you only one type of morphology, and the plume conduits are predicted to be rather thin, more like 200 kilometers. So this is at odds with what is observed. We do have plumes, but this seems to be fatter. And then this type of convection is not producing surface plate, and it's not producing either two domains, for example, as has been identified in the mantle. So in order to explain more about plumes, in fact if you remember that the mantle contains a lot of heterogeneities in composition, so heterogeneities in density, then you can run experiments by, for example, introducing some salt to densify your fluid. So here it's in orange. And then if you look at how plumes develop, you see that as the buoyancy ratio, which is the ratio of the chemical density contrast, which is stabilizing the flow over the thermal density contrast, is increasing, then you're going to change very drastically the shape of the plume from the classical mushroom shapes to much more contorted, even to pile and so on. So with this kind of phenomenon, you can explain, you can predict that there should be several types of plumes that could occur in the mantle, and you can also explain why plumes could be fatter, because in those thermochemical plumes, you have very often pre-circulation within the conduit, so that it gets thicker. So we can also generalize this result by looking at the full system, the full blown system of the whole mantle, both in the lab or numerically, and then you predict that can coexist several types of plumes, once the mantle has started to convict for a long time, because it will contain probably heterogeneities of different intensities. So you can explain with this sort of modeling how you could get several types of spots, several types of plumes, and LLSVPs. On the other hand, it doesn't give you any reason why you should get plates, and then you have to invoke something else, which is how the fluid is going to deform. If you take rocks, they have a viscosity that depends very strongly on temperature. They're much stiffer at colder temperature than at hot temperature. So it's going to introduce a very strong asymmetry between the hot current and the cold current in your convective box. So the pattern now is going to depends on the viscosity ratio between the hot material and the cold material. If you apply the physical laws to the Earth's mantle, then you predict that you're going to have convection below one stagnant plate. So it's a good way to make a plate, but the problem is to break it. And so to break a plate, you need more complex fluid. In fact, when we look at rocks, we see that rocks can yield a break if the applied stress or force under which they are is higher than a threshold. So if you get this in a everyday fluid, like for example, paint, and you use this type of colloidal dispersion in our fish tank system, when you see convection, then you are forming a plate on the surface, but this plate now can break. And when it is breaking, you got one-sided one-sided subduction as it is observed on Earth. You can get also a very strong interaction between plume and subduction, even originate subduction by plume. And you can observe also all the accretion phenomena like microplates and transform faults over lappers that you see on Middle Eastern regions. So this approach using soft matter material, especially complex fluid, can be very helpful to understand how the rheology, the way your fluid is deforming, is going to influence the convective regime of a planet. So we see that there is a lot more convective regime that shows plate tectonics or stagnant lead convection. So we have a lot more to explore, and we have especially to understand how a system can transition from one regime to the other. And one of the key ingredient, I think, to understand now is to understand how the fluid texture and the way it deforms is going to influence the convective pattern. There is right now a really lack in the theory and the lack in mathematical formula to describe this type of deformation and to get a good experimental database can really help to solve the problem. So thank you very much. Thank you so much. And the next speaker will be Paola Kolemair. Good afternoon. My name is Paola Kolemair, and I'm a global seismologist. And it's a pleasure to speak to you today and talk about the landscapes of the deep earth with you. Charles Verne already imagined all kinds of landscapes within the deep earth during the journey of Professor Leidenberg to the center of the earth, and she can read here in this description of the central ocean. And we may not have a sea at the center of the earth as he imagined, but we certainly have landscapes within the earth, just as on the earth's surface as we can have mountains and valleys on internal boundaries, topography variations. But also, just like the soil and the vegetation are part of landscapes on the earth's surface, we can say that in the deep earth, the three-dimensional structures that we find here also form part of our landscapes. I have now found that particularly, under Africa and the center Pacific, there are two mountainous regions on top of the core that are a few kilometers higher in elevation. And you can see these regions here in this three-dimensional model of the core-mantle boundary topography. Constraining this topography is important because it tells us about the flow of material in the earth. For example, when we have a downwelling cold plate, we expect this to depress a boundary, as you can see in this cartoon. But if we have upwelling hot material, we expect an elevated boundary. And this flow of material determines how heat is removed from our planet, which is ultimately important for a lot of dynamic processes, such as mantle convection and plate tectonics, as well as the generation of the Earth's magnetic field because it also extracts heat from the earth's core. However, it's very difficult to see inside the earth and to image these landscapes because these structures are thousands of kilometers below our feet. Seismic waves that arise after earthquakes can act as our eyes and allow us to see these images, these landscapes. And it is as if the material in between is made out of glass. Of course, there are complications. So we are not looking entirely through transparent glass when we're trying to image these landscapes. But seismic waves still allow us to see the deep earth. Typically, we use waves traveling from through the earth after earthquakes that are reflecting and refracting around the core, which you can see here in these blue and red paths. However, they do not provide us with data everywhere and would lead only to patchy observations of these landscapes. Alternatively, we can use observations of the standing waves of the earth that only arise after large-magnet earthquakes. And the resonance frequencies of these whole earth oscillations are also affected by our landscapes. The measurements of these resonance frequencies automatically provide us with global data coverage. And there are a number of oscillations that are specifically sensitive to the core mental boundary. By analyzing existing models from different groups based on these standing wave data, I have found that there are particularly two areas of elevated topography on the core here under Africa and under the Pacific, which you can see in these red colors. And there's valleys or canyons in between under the Caribbean and underneath Indonesia. Specifically, the locations of these mountains coincide with the locations of the large low velocity provinces or LLVPs, which are two giant blobs that are imaged in the seismic velocity structure of the lower mantle, which you can see here on the right. And you see these two red structures. Although these are imaged very consistently between different tomographic models, we don't have unique interpretations what causes these low seismic velocities, whether this is due to high temperatures or whether these have strong chemical variations. Strong constraints are provided by the density structure, which you can now see on the right hand side. And again, by analyzing existing models, I have found that the dense parts of these LVPs seem to be localized in two smaller scale regions, roughly centered below Angola and close to Hawaii. And specifically, when you compare this with the topography, which you can see on the left hand side, we see that where we have these dense areas, we have less elevated topography. And it is as if these dense areas are surrounded by a ring of higher stronger elevation in the core topography. These observations tell us that these giant structures, these LLVPs, underneath the Pacific and underneath Africa, and here you can see a rendering of the one underneath Africa showing its vast extent, that these can't be entirely dense structures, but that the dense anomalies are limited to smaller areas within these structures. And that implies that there's a balance between the thermal and the chemical variations, which leads to these small dense areas. At the same time, the elevated topography suggests that upward flow occurs at these locations, which is important to constrain further, as these giant structures influence the way the earth cools down and loses heat over time. Thank you very much for your attention, and I'm happy to take any questions later. Thank you so much. We'll end our journey, returning back to the surface of the earth with Filippo. Right. Okay, good afternoon, everybody. First of all, let me thank Terry for this opportunity to share my research. We are at the end of this journey, and I am like an end user because, yes, what we will speak about is the effects of eruptions. First of all, I am a researcher at the University of Bologna, just to present myself quickly, and my research activity deals with the numerical models of landslides and tsunamis. So, what I am going to show you is some preliminary results coming from these analyses we did on mass failures occurring in Stromboli Island. As you can see, I think you know very well Stromboli. It is a volcanic island, and it is frequently affected by mass failures. There are collapses along its flanks. These collapses are provoked by many aspects of volcanic activity, and occasionally they can generate tsunamis, and tsunamis can be also catastrophic, especially in local scale. So, what we did in this work and what I will try to show you is some simple relation that wants to link the landslide and the tsunami that is generated by them, and this simple relation that can also be used for the hazard management. We are still in the beginning phase, so we are still far from this application, but at least we are trying to look for some relation. This very complicated natural phenomenon. So, two words about Stromboli. It is a volcanic island, as I told you. It is located in the Tyrrhenian Sea. It is a very peculiar volcanic activity that is characterized by frequent eruptions, and also occasionally extreme events like the one in last summer. From the landslide collapse point of view, what is main interesting from our side is the big scar on the northwest flank of the volcano. It is a scar that was generated by an ancient collapse of the volcanic edifice, and most of the material that goes out from the crater is channeled to the sea along this scar. So, most of these slides, of course, along this shard of the volcano. In the catalogs, there are 10 tsunamis that are reported in the last 150 years in the Heolian archipelago. The most recent, as I told you, is the last summer, and another one was in 2002 that provoked waves of 10 meters elevation all around the island. So, they were very big effects. The strategy of this presentation of our work that we are doing, we are doing modeling. So, we start from landslide scenarios. We depict 61 different cases of landslides along the shard of the volcano. We perform the tsunami simulation generated by these landslides, and then we look for the correlation between the two phenomena, trying to describe the landslides and the tsunami with some typical main parameters that can, in some way, describe them. For example, for landslide, usually the question is, what is its volume? How deep is it? So, we can also look for different characteristics of the slides, and also for the tsunami, usually the most important and the most searched one is the maximum water 8. And then we try to look for some correlation about these quantities, and I will show you some plots. First of all, the scenarios. Just two words on the world scenarios. Scenarios here means that we are doing hypothetical landslides. These are not the simulation of what occurred, or at least they are not only them. In fact, for example, scenarios B, C and D are based on the 2002 events. We vary the volume of the landslides from a very small half million cubic meters to the big one, that is the F scenario here, that is the one that generated the Sheridan Focco. So, we try to keep into, to take into consideration a wide range of possible landslide along the Sheridan Focco. So, this is an example, just one, and I don't want to go too much in the details and technical issues about this. But an example of the plots that we can obtain is this one. On the horizontal axis, we have the potential energy of the slide. On the vertical, there is the maximum water elevation that we are simulating and measuring on one single tide gauge. The tide gauge you can see here from the harrow is located in two kilometers northeast of Stromboli. So, how can we use this plot like this? For example, we know that we have a potential slide. We can try to imagine what is its potential energy. So, we go in the horizontal axis and crossing one of these lines. I don't know again in the details of what we did, why there are two lines. We can imagine what is the maximum water elevation in that specific location. There are, as I told, the other relevant characteristic of the tsunami is the maximum energy, the total energy of the tsunami, other more physical quantities. But from the practical point of view, this can be interesting because we can, in some way, try to assess what is the effect of a slide in terms of maximum water elevation over one single point. This is a similar plot, but it represents the computation of and the same linear relation that I showed before. But in another tide gauge, this is a simulation in a more distant tide gauge along the Calabrian coast. And what is surprising and also interesting for us is that the slope of these lines are the same as the previous one are very similar. It is very promising because this is linearity. Okay, we are on a longer scale, so it is not a direct proportionality. But it is very interesting because tsunamis and steep lines are very common to know that finding these regularities is something that is very welcome. So we think that is very promising. Okay, that's all. And I wait for your question. Thank you very much. Okay. Do we have any questions? Okay. Well, if there's no questions then, we'll finish here. And thank you, everyone, for joining us. I hope to see you all in person in Vienna next year during EGU 2021, which will take place the last week of April. Thank you very much for coming.