 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 10,000 people from around the globe participating in our events. I'm Teri Cook, EJU's head of media communications and outreach, and I'll be hosting this week's press conferences, which include a question-and-answer period following presentations by our four speakers. This is the first time we've ever tried completely remote press conferences, and we may experience some technical difficulties. If the platform suddenly quits during the middle of the press conference, I'll restart it, and I'll give everyone about five minutes to rejoin this session. The transitions can also be a little bit slow, so I ask for your patience while we test this new greener way of holding geoscience press briefings. At the end, after the presentations are over, journalists will have the opportunity to ask questions, and I ask that you please only use Zoom's Q&A function, knock the chat to ask these, and we also will not be using the hand-raising function during this session. Journalists, the abstracts, and other documents relating to the press conferences have already been uploaded to the document section of the media website, which is 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. The press conference is titled Centennial Perspectives, a celebration of Marie Tharp's legacy, and it's an honor of the 100th anniversary of this famous scientist's birth. Our speakers today are Vicky Farini, who is a research scientist at the Lamont-Doherty Earth Observatory at Columbia University. Also Matilde Canat, a marine geoscientist from the Institut des Physiques du Globe de Paris in Paris. Paul Wessel, who unfortunately will not be able to attend in person, he's from the University of Hawaii at Manawa, and it's so early there that he has sent a video instead, so I'll be playing that, and he is a professor at the SOEST there at the University of Hawaii. And then Florian Schmidt is a post-doctoral researcher at GOMAR, the Helmholtz Center for Ocean Research in Kiel, Germany. So I'll now hand over to them and open the floor for questions from journalists after the scientists have finished presenting. All right, just confirming that that's looking correct. Yes. All right, so thank you. It's a real honor and privilege to kick this off. I would like to acknowledge my co-authors for my presentation that's later in the week, Bill Ryan, who has been at Lamont since Marie Tharp's time and worked with her back in the early days. Also Suzanne Carbot and Suzanne O'Hara, who have been at Lamont longer than I, and have helped to carry some of her legacy forward. I'm going to give you a little bit of background from the seafloor mapping perspective because that's my expertise. So when Marie Tharp did her work at Lamont in the 50s, 60s, and 70s, she worked from paper echo sounding records, as shown with these pictures here. And what she did is she translated those into profiles, like what's shown in the top on the right. And then she put those profiles along where the transects of data were collected and she stylized her interpretation of what she thought these profiles meant. So this is one of the examples of a stylized couple of profiles. And then doing what we now do with computers with her mind and her mathematics and her understanding of geology, she basically interpolated between those transects to fill the gaps with more of these stylized renderings, which as you can imagine was fairly disruptive in those days, but really transformed our understanding of the seafloor. So in doing that kind of work, she revolutionized our understanding of the shape, texture, and fabric of the seafloor. Prior to her doing this work, maps like this, which is an early Jebco map, which is the general bathymetric chart of the ocean, they were presented as contours. And so you could see the general shape, but you could not see the kinds of detail that you can see with these physiographic diagrams that she put together. And what's particularly inspiring and incredible about the work that she did with very sparse data is that these maps that she created are indeed remarkably similar to what we see when we actually measure the seafloor with echo soundings at much higher density. This is the famous 1977 World Ocean Floor map that Marie Tharp and Bruce Hazen put together by working with Austrian painter Heinrich Baran. He was a famous painter that did panoramic maps combining cartography and classical painting. And by doing this work together, they were able to really make it much more understandable both to scientists, but also to the general public by using vertical exaggeration and incredible detail when you look at this up close to see the shape of the seafloor that really helped us understand all kinds of things about the planet, in particular the mid-ocean ridge system and fracture zones, and we'll hear more about various geologic interpretations in the next talks. My presentation on Thursday is really focused on something that I latch on to a lot because of my work, which is really an important part of her legacy, which has been codified in the evolution of bathymetry synthesis that have been initiated and continued at Lamont. And so I present a timeline in my talk later in the week or my little video that I put together, but a few highlights here. There was the 1957 initial map that was produced, the physiographic map of the Atlantic, and the next big timeline event, perhaps was the 1977 World Ocean map where we could see the entire seafloor advance a decade and a half to 1992 with the ridge multi-beam synthesis that was initiated by some of my predecessors and colleagues at Lamont, really taking advantage of digital data and multi-beam sonar data to build digital models of the mid-ocean ridges based on data from lots of different cruises and bringing that together into a synthesis. That then evolved over the next decade into what now still exists as the global multi-resolution topography synthesis, which I work on with a lot of my time and basically the transition of knowledge and continuity of work that was done there really helped to evolve the way that things have been done from hand drawing and interpolating with this incredible mind understanding the seafloor to digital data and gridding the data into digital elevation models to GMRT, which is a multi- resolution synthesis of global ocean bathymetry. Today in 2020 GMRT, the data in there from multi-beam systems covers 9% of the ocean floor, which to me is a huge achievement, but really when you think about it, it's still a tiny little fraction of the seafloor. And so where we are now and looking toward the future toward 2030, there's a new initiative that started a couple of years ago called the Nipon Foundation Jebco Seabed 2030 Project. It's a partnership between the Nipon Foundation and Jebco, and Jebco is tightly affiliated with the International Hydrographic Organization and the Intergovernmental Oceanographic Commission of UNESCO. And really the vision here is to bring the entire international community of stakeholders, whether they be scientists or industry representatives, anyone who's collecting bathymetry data to pool our data and our resources to achieve the goal of mapping the entire seafloor by the year 2030. So we're still working to complete the vision of what Marie Tharp started back in the early days of Lamont, much like the quote that's here where she talks about viewing the seafloor as a jigsaw puzzle. I say I would like say that I certainly view it the same way. It's really like a big puzzle. We're trying to put together and bring all these different data sets together to get a complete view of the seafloor. And it's a real honor and privilege to be able to continue this effort and work toward completing that goal. So with that, I will pass the baton. Okay, so I don't know if you can hear me. So yes, it's a really exciting thing to map the seafloor. And it's really amazing to understand that prior to the activity of Marie Tharp in the 1950s, we indeed knew very, very little about the topography of about 70% of our gross surface of the Earth surface. So Marie Tharp, what she did, I think Vicky explained it very well. She had very scarce data and she managed to produce not really maps, but what she called physiographic diagrams that represented the topography in amazingly accurate ways. And the reason why it was so accurate is because it was not just taking a point of topography and putting it on a map as would be done with cultural maps, for example. But it was really understanding the geology and then reflecting this understanding in the way she was drawing the maps of these physiographic maps. So what she did was producing these maps that came at a time in the early 50s and then the early 60s when people were actually discovering plate tectonics. And it's absolutely certain that without these incredible documents, the plate tectonics theory wouldn't have taken the shape it has taken and suddenly wouldn't have been popular so fast. She also described a lot of identified several key and first-order geological features of our planet. She was the first really to understand the role of Middlesen bridges as the place where the plates are diverging or pulling apart. And she also discovered these amazing structures. She actually mapped these amazing structures and then they were progressively interpreted as a science is always a collective effort that are called fracture zones and that are really key to understand how plates move apart. So these are two photographs of Maritha. One is when she was really young and had just been hired at Lamont's Doherty, where she actually worked for her entire career as a cartographer, not as a research scientist. And yet as I told you in the first slide, it's actually absolutely clear that her approach of mapping was that of a research scientist. And here is one photograph in July 2001 when she received a pretty prestigious award at the same institute. Okay and this is one of these physiographic diagrams and it's a focus on the Azores region and what I wanted to show here and actually Vicky showed the same map, the same part of the map, but I want to show it to you in more details because when you look at the at the left hand side, it looks really outdated. It looks like one of these 18th century landscape type maps that you see in old books. But in fact, when you look at the details on this map, and I'm going to try with my pointer, you see for example this flat top cement is great material. And here what I've done is I've extracted and viewed a little bit on 3D view of this most recent GMRT grid map that Vicky told you about. So that's basically our most recent compilation of knowledge on the bathymetry of the oceans. And you see that the map really shows that very well. Amazingly the Atlantis cement that is very complicated and not that well understood feature. When you look at the present day map and Mary's map here, it's amazingly accurate. And of course one of the main achievements of Mary thought was really to discover this could use a chain or valley that is called the Mid-Atlantic Ridge or the global ridge system. And if you look at how it's mapped here with the Azores Islands on each side, you see here the Azores Islands and you see the Mid-Atlantic Ridge Valley. So everything is there. All with, as Vicky said, very few cross cutting profiles but a very keen understanding of what the geology was like that allowed her to draw beyond what was actually really measured and be accurate. And this is another example of a work she did with Bruce Hezham who was actually a research scientist working with her at Lamont. And based on her mapping, they started interpreting the geodynamics of the several regions of the globe. And I see here one of the most amazing achievements was mapping the tectonics of the Indian Ocean. And again, this is the most recent GMRT map here with the little dots here are the most recent model of plate boundaries that we have. And you see that it is pretty much there in this 1965 map. And what's incredible also is that you see these little arrows and they mark the displacement of the plate. And here you've got for the continents it's big black arrows. So it's an incredibly high quality work and tectonic interpretation. One thing they did is that they assumed that the spreading at Mid-Atlantic Ridge was always pretty much perpendicular to the ridge. And so it worked well for most ridges. It didn't work that well for this one, the southwestern ridge. And I'm going to finish my talk just showing you how we still are using seaflow mapping to understand the geodynamics of the Indian Oceans. And of course the plate motion we know now here is not perpendicular to the ridge, but it's a bit to the ridge. So just here, this huge from the book that shows the chronology of Maritha's contributions with mapping from 1952 all the way to 1967. And you see this huge work of mapping of all the oceans. And then the publication of this national geographic kind of broad public general map of the ocean that is really famous. And underneath what's there is some key papers about that led to the discovery of plate tectonics. And you see that it's remarkable that her work mapping laid the foundation for these amazing discoveries. So I'll just go very fast on some work we've been doing with maps of the ocean floor in the southwestern ridge. So the ridge is here. And this is a pretty large bathymetric map. It's about 150 kilometers on each side. And it's relatively well resolved. It's much better resolved of course than Maritha's maps. And what this resolution allows us to do is to look at the shape of the relief and interpret it in terms of tectonics and all the plates are spreading about. And it allowed us to discover that there are parts of the ridge that actually work with very little magma. And this is something that I've just been presenting this work actually in the chat of this TS6.4 session. So I will go fast on this presentation because it's not, but just to show you how from bathymetric maps and seafloor imagery, for example, these seafloor imagery shows you very nicely where you have basalt because they are bumpy. The basalt edifices, they make these little bumpy ridges. And when it's flat here, it's this very strange seafloor we've discovered that is made almost entirely of matter works. And the interpretation is that the plate spread without magma and therefore what is forming the seafloor is the material that is in the earth matter and is uplifted by big folds. And we have this sketch with these folds that relate. The red one is active now, but it has cut the purple one that itself cuts two billion years ago into this green one. And so I think that's my last slide. Yes, it's just to show that with this type of mapping material we can really discover in much better detail how middle-seek ridges work and how particularly when there is enough magma, the plates move apart because you inject more magma. And when there is not enough magma, well, folds take over. And there is a, we can find evidence of a smooth transition between the two. Okay. And I'll just finish with this, with the announcement for this session, TS14.1 that will have a chat on Thursday. And that is celebrating the 100th birth anniversary of Maritha for her truly amazing contribution. Thank you so much. I will now share Paul Wessel's video. The area is with limited high-resolution data. And the Cretaceous, good afternoon. So seafloor epithymetry and tectonic fabric is fundamental information that informs models for plate tectonic evolution. However, the earth is very unevenly mapped by surface ships, leaving large areas with limited high-resolution data. And the Cretaceous, at least basins in the Pacific equatorial region, shown here with the red oval between Antonjava and Manhiki-Patoes, is one such area. So this area is poorly surveyed by surface ship, gotten better, but still incompletely mapped. In fact, it is not that different from what Heeson-Tharp made back in the 60s before we had altimetry maps. The regional understanding of this area got much better once seafloor epithymetry was introduced. And Bill Hacksby's tennis map made a huge step leap forward in understanding global scale and regional scale tectonics. Yet it turns out that at the smallest scale, the highest resolution, we still require multi-beam ecosounders, despite efforts like Samo and Smith here, trying to squeeze as much data out of timetry as possible, running into physical limits such as popular continuation. So here's the famous Hacksby map from 1987, based on three months of CSAT data. It looks great on a global scale. Here we're looking at several 3,000 kilometers of the L-spacen. It got better once Geosat came into picture with Samo Smith processing that data in the mid-90s. To go forward in time, new satellites come aboard like Jason, MvSat, Cryosat, and most recently Altica, leaving a much clearer picture of the Earth's gravity field. You can see some structure in the central L-spacen from this data. However, tectonics requires sharp boundaries and lines, and so we rely on a derivative of the chief potential called the vertical gravity gradient. Being a derivative, it highlights rapid changes, so it makes fracture zones and ridges standouts. However, abyssal hills, which is also important for tectonics, is still not well mapped, especially in deep ocean basins. As they go to bathymetry, pre-altimetry, the situation was pretty bleak. There's hardly any features in the L-spacen on this E-couple-5 map. But once altimetry was used to make predictions about the bathymetry, it would have to be to match the gravity. We started to see much more features. So, Samo Smith have come up with a recipe to predict bathymetry from gravity, and this process is informed by all available bathymetry data that is available. So, we have this slide with the recently released SRTM 15 version 2.1, which is a global 15-art second grid, which is the most complete map of the oceans to date. Yeah, if you look at the L-spacen, it is pretty out of focus, not a lot of detail. So, a few years ago, we led an expedition to the L-spacen to try to understand the tectonic evolution in this cretacean space. And we spent 40 days out there to see. We decided to serve it in middle based on very limited data and predictions from the vertical gravity gradients. The mapping revealed very complex tectonics with propagating rifts and fractured zone reorientations and probably rich jumps. Timing is still uncertain. It's all happening during the cretaceous normal supercrone, but the oxenrock samples and Anthony Copper's and his team are still working on data. So, we take in the bathymetry that was possible and it's been visualized with GMT to make a quadtree representation for Google Earth. So, in this movie, we are in Google Earth looking at the vertical gravity gradient background, which gives the global picture of the tectonics. And zooming in on our 40 days of ship data, which covers about a quarter of the L-spacen. As we go closer here in this little jerky, we can start to see the complexities of the data in this central portion. We see propagating rifts. We see rotational fabric. There is clearly some rich jumps happen. Fractured zones have been easily reoriented during a period. And it's all overprinted with a recent volcanism. This picture we're looking at has been interpreted by us. We published a paper in tectonics last November with student Elizabeth Benzek as the first author. But I'm sure more revision will be needed and even more data will be needed to understand the whole evolution of the L-spacen. And I'm happy to take any questions offline. Thank you. Okay. Hello. Hello to all from my side. We will stay in the region and I will show another example of works, which are pretty much in the legacy of Marie Farb. And the region we are focusing on is actually a little bit south of the L-spacen. It's the so-called Lao Basin, which you see here in the center map. Here you see an overview. And the interesting thing about the Lao Basin is that nowhere else on Earth there is a process of crustal destruction and creation in such proximity as fast as happening as here. And this is really a geologist's paradise. And I'll tell you why. Because if we see here, the subduction of the Pacific plate under the Tonga plate is happening at really fast pace. And due to this pull down of the Pacific plate into the Tonga trench is wandering eastwards. And this leads to an opening of the Lao Basin at velocities of about 15 centimeters per year. And the interesting thing is due to this relatively fast opening rate, we have the situation that at this latitude of about 17 degrees south, there's actually two extension zones. And this is pretty unique. And while, as you can see here, the symmetry is already quite complete because there have been a lot of studies in the last decades, which started out in the 70s. And we have a pretty complete picture is going on in the geology right now. But regarding the geological evolution, there's still a lot of open questions. For example, how did these spreading centers evolve? And how did the crust actually form in here? Was it more tectonics? Was it more magnetics, which were important processes? And to look at this tectonic evolution there, we performed a geophysical experiment late in 2018. And this led to a geophysical transect, which you can see here in this map. And we required seismic data and magnetic and gravity data. And now I will show you what, so here you can see some impressions of what we did. And I will share some key results of this work, which is still ongoing. And so we found that also on the top, you see a map of the basymetry. Then you see a geophysical model, which I created for the crust. You can basically imagine this as being a slice right through the crust structure. And at the bottom is an important plot, which shows actually similarity in the crustal structure, which is somehow related to the lithology or the rocks which are composing the crust. And so we found that there in the crust, which is related from the similarity and the seismic velocity, that there's actually big blocks of structure, which are similar, which you see here in red, which are similar to the volcanic arc structure. And then we have other regions, which I marked out here, mapped out here, with the hatched areas, which are similar to oceanic crust. And if we transfer this into how has evolution of this region happened, it shows that these blocks are the result of pretty different processes. And so it shows that the evolution here was not straightforward, but it was rather periods where tectonics were more important. And so-called rifting was of importance. And then other periods where these hatched areas were created, it was that magnetism was an important process. And one of the major outcomes of this is that now we can take the knowledge of how this happened along our profile and transfer it into the the mapping dimension and can create geological maps and put together this jigsaw of processing, creating the crust there. Yeah, and this is all I wanted to share. Great. Thank you so much for all of your presentations. And would any members of the press like to ask questions using the Q&A function now? Okay. The first question, which I believe is for Vicky, is what will it take to meet the 2030 GEPCO target, particularly in the more remote locations like the Southern Ocean, where there's some very interesting tectonic behavior? Well, it's a very good question. The 2030 target is definitely quite ambitious. I think the way that we are envisioning this is that it's really an all hands on deck kind of call. We're anticipating the use of combined assets, such as research vessels, industry data, wherever it's available, autonomous vessels, emerging technology. We really need to figure out how we can bring all these great technologies together and work together toward reaching this common goal. An important part of that is making it clear to all the stakeholders what the benefits of sharing data and working together toward this are. And I think there are many, and that's actually a quite easy argument to make in many ways. But really getting everyone to the table and figuring out how we can work together with both the technology for data acquisition and the technology for crunching and assembling data is going to be the magic ticket. Great. Thank you. Are there any additional questions? Okay. Can you just explain a little more how extension occurs without magnetic intrusion? Okay. So when two plates move apart, if you wanted to look at it in a very simple way, but it's not so far from the actual way we look at it, is that the space between these two plates that are moving apart a few centimeters every year has to be filled by something. And this something can either be magma that's produced in the mantle and rises to the surface and gets intruded, or it can be metal that is brought from the depth and placed at the seafarer. And so then the real question is how can you make faults that are able to do this thing, to bring rocks from the upper matter of the earth and then place them in the seafarer. And we've been discovering as a community, the rich community for the past two decades, that there are actually very large normal faults that are active at middle-sleep ridges. At slow-spreading ridges, ridges that spread the plates at less than four centimeters per year, these faults are actually very common. They occur around about 50% of the length of the ridges. And because the fault uplifts the mantle only on one side, it amounts to about 25% of the surface of the new seafarer that's created. And then there are some very strange places, like the place we discovered at the south-western and ridge, which for various reasons, the main reason is probably because the upper mantle of the earth in this particular region is bizarre. It's colder than normal. And so it produces less melt. And what it does is that because there is less melt, this melt focuses to large volcanoes along the axis and less melt on the surrounding areas. And so you end up with places where you actually spread the plates with only the big faults. Great. Thank you so much. Are there any additional questions? Okay, there's one more. The discovery of plate tectonics involved many actors, but where in that story would you put the importance of Marie Tharp's contributions? I don't... So maybe it's for me too. As I try to explain, Marie Tharp's contribution comes before. And it's like the grand work for being able to really describe the plate tectonics. Because the key thing about plate tectonics is that the key point is that we have on our planet a mechanism that constantly rejuvenates the surface of the oceans. I mean the ocean seafloor, the oceans. And the oceans are very young. And therefore in order to re-understand plate tectonics, you really need to have good maps of the oceans. And so the contribution of having a good map of the ocean is essential. The other key contribution is that she really discovered the middle-sleek ridges. And it's actually a story that is worth telling a little bit, is that her status, as I said, was not one of her research, or she was a cartographer or technician. And the reason for that was double. Once she didn't have a PhD, and you have to understand that at that time it was actually not... Very few women actually went all the way to the PhD in science. And the other reason was that she couldn't go on the ships because the research vessels at that time were not accommodating women. And therefore she couldn't. Her position was to stay at the lab and make these maps. And doing that she, as I said, developed a geological understanding. And she understood that the middle-sleek ridges were like these big rift valleys. And she also made the connection with the fact that she had seen published maps of the seismicity. Because at that time the seismologists had come together. And I mean, ever since the early 19th century, seismologists had started to record the seismic events all the way, all around the planet. And she discovered that these ridges that she was mapping and discovering coincided with the very active, very seismically active regions. And she put the two together and actually had a big problem, big job. It took her a long time to convince her hierarchy, if you want, so that would be that would be Hezen and even more the head of the lab, Maurice Ewing, to persuade them that her understanding of the ridges was correct. And the sad thing is that after having done all of that she never got into a first author position on the paper because she was not a full-fledged research scientist. Thank you very much. Florian or Vicky, would you have anything to add to that? Yeah, I would just add that Marie Tharp's work is one of the best early examples of what comes from sharing data and integrating data from multiple sources. And as we proceed in the more modern and digital scientific environment, and we become more and more comfortable with this idea of sharing our data with other scientists and really building this pool of knowledge, I think it can be inspired by the work that she and Hezen did back, you know, 50, 60 years ago, doing exactly this, working in analog, but really pulling together all this data and gaining new and really important insights about the planet. Thank you. Nothing to add here. Great. Are there any additional questions? Okay. This is perhaps a question for Paul, but maybe Vicky can answer. Is there any more detail to squeeze out of the satellite's gravity data or have we reached the limit of what's possible in mapping the seafloor from space? So my opinion is based on what I've seen and what I've seen colleagues do looking at this, we've kind of met that critical point. As the gravity models become better, it's often largely due to the addition of actual measured bathymetry data. However, there are certainly airborne techniques that will continue to improve our mapping capabilities and our ability to see through the water, so to speak. So we may have reached the limit with gravity data or we're approaching that limit, but using satellites to image and measure bathymetry in shallow water is certainly an emerging field that is very promising and hopefully will help us gain great efficiency as we try to map the rest of the planet. Great. Florian or Matilda, do you have anything to add to that? No. Okay, thank you. Great. Are there any additional questions? I should also mention that Paul said at the end of his video that he is happy to take questions offline. His email address is pwessel at hawaii.edu and he's happy to answer questions as well. We'll give people just another minute to ask. I'd like to also announce, like Matilda mentioned, that Thursday afternoon at 1400, the session TS14.1 is devoted to celebrating Marie Tharp's legacy, so there'll be many more interesting presentations there. And if there are there any additional questions? Great. Well, if there's no more questions, we'll finish here. Thank you all for coming.