Landscapes Live

EGU-GM Online Seminars in Geomorphology

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Landscapes Live is a weekly online seminar series freely accessible to the international scientific community interested in various aspects of geomorphology. Our talks take place on Zoom every Thursday, starting at 4pm time of Paris/Berlin/Amsterdam. Check your local time here.

Landscapes Live is affiliated to the Geomorphology (GM) division of EGU and contribute to develop its virtual activities. Indeed, EGU is pioneering a new CampFire concept to bring together the geoscience community in between General Assemblies. We hope that this will meet the needs of the current pandemic but also help us in our transition to a greener future and ensure that our community better serve the needs of all scientists regardless of international mobility.

Program (Fall 2022):

06 October 2022 - Gino de Gelder (University of Grenoble) "Inverting marine terrace morphology to constrain paleo sea-level"

→ To register: https://univ-grenoble-alpes-fr.zoom.us/meeting/register/tJIvcOirrT0vHN1kf3FRKeD6POOPHOP3NJcM

Abstract: Quantifying paleo sea-level variations is of fundamental importance to understand the complex relations between paleo-climate, -ice-sheets and geodynamics, yet uncertainties prior to the Holocene currently span several tens of meters. The world’s coastlines present an enormous geomorphologic dataset of relative sea-level changes, and recent studies have shown how they can be used within forward landscape evolution models. We take a next step, and apply a Bayesian approach to invert the geometry of marine terrace sequences to paleo sea-level. Using a Markov chain Monte Carlo sampling method, we test our model on both synthetic profiles and observed marine terrace sequences from Santa Cruz (Ca, US) and the Corinth Rift (Greece). The synthetic profiles – with known input parameters – show that there are optimal values for uplift rate and erosion rate to obtain a well-constrained inversion. Both the inversion of synthetic profiles and real sequences show how sea-level peaks are easier to constrain than sea-level troughs, but that also solutions for peaks tend to be non-unique. Synthetic profiles and profiles from several sites in the Corinth Rift both show how inverting multiple profiles from a sequence can lead to a narrower range of possible paleo sea-level, especially for sea-level troughs. This last result emphasizes the potential of inverting coastal morphology, suggesting that joint inversion of globally distributed marine terrace profiles may eventually catalyse a better understanding of local/global paleo sea-level and glacio-isostatic adjustments.

20 October 2022 - Steffi Tofelde (University of Potsdam) "What sets the width of valley floors?"

→ To register:

Abstract: The geometries of river valleys range from deeply incised canyons with narrow or no floodplains to cross-sections of kilometer-wide, densely populated plains. The shape of river valleys is the product of the interplay between tectonic uplift and erosion by rivers. Rivers deepen valleys through vertical incision and widen valleys by lateral erosion of the enclosing valley walls. While the processes and rates of river incision have been studied extensively in recent decades, comparably little is known about lateral river erosion and controls on valley-floor width. Field measurements of valley floors are sparse, but generally indicate that valleys are narrower at sites of enhanced uplift and row wider with greater river discharge and in softer lithologies. However, the order-of-magnitude scatter in these data suggests other, as yet unquantified, factors that influence valley-floor width. Paired river terraces - staircases of ancient floodplains preserved at different heights on either side of the valley - preserve information about past valley widths. We extracted valley width and height from climatically formed, alluvial river-terrace sequences and showed that valley height explains 90-99% of the variance in valley width at a given site. To explain the observed valley-width-height relationship, we propose that the amount of lateral sediment supply from valley walls, in addition to river discharge and lithology, controls valley-floor width.



27 October 2022 - David Montgomery (University of Washington, Seattle) "The geomorphology of farming and health — how soil health connects to human health"

→ To register:

Abstract: We all know that diet matters and have heard the adage "you are what you eat." But dig a little deeper and it becomes clear that what our food eats—how we grow crops and raise animals—rounds out the full story. Farming practices intimately influence soil health which in turn affects the amount of health protective micronutrients and phytochemicals in our crops. And what we feed livestock affects the mix of fats in meat and dairy products. Modern farming practices reliant on frequent tillage, excessive applications of soluble nitrogen fertilizers, and reliance on pesticides have degraded agricultural soils and reduced the amount of beneficial compounds in foods. Yet farmers in both the industrialized and developing worlds are changing their practices to improve soil health through minimizing soil disturbance, planting cover crops, and diversifying the crops they grow. These practices combine ancient wisdom with modern science revealing that there are ways to farm that provide sufficient yields and foods suffused with the array of compounds that help underpin human health. It turns out that what’s good for the land is good for us too.

03 November 2022 - Nathan Brown (University of Texas, Arlington) "Resolving surficial processes using luminescence thermochronology "

→ To register:

Abstract: Luminescence dating is commonly used to constrain when sediment was last exposed to sunlight. For mineral grains within the dark interior of a rock outcrop, however, the luminescence signals relate to thermal exposure. For example, with grains kept at a constant temperature for time periods longer than several hundred thousand years, luminescence signals can be used to estimate that storage temperature over a wide range, from upper-crustal through atmospheric temperatures (paleothermometry). Conversely, grains which have changed temperature recently can embed information about their time-temperature history (thermochronology).

In this presentation, I will review the basic principles underlying luminescence thermochronology, some example applications, and future research directions, with emphasis on understanding surficial processes. Advantages of this technique include the ubiquity of target minerals (primarily K-feldspar), its sensitivity to low temperatures and recent time periods, as well as the diversity of luminescence signals which can be measured from a single sample to gain additional information of a sample’s geothermal history.

10 November 2022 - Laure Guerit (CNRS and University of Rennes) "Title to be announced"

→ To register:

Abstract:

17 November 2022 - Clément Désormeaux (Aix-Marseille University) "Investigation of stochastic-threshold incision models across a climatic and morphological gradient "

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Abstract: Long-term landscape evolution is controlled by tectonic and climatic forcing acting through surface processes. Rivers are the main drivers of continental denudation because they set the base level of most hillslopes. The mechanisms of fluvial incision are thus a key focus in geomorphological research and require accurate representation and models. River incision is often modeled with a stream power model (SPM) based on the along-stream evolution of drainage area and channel elevation gradient but can also incorporate more complex processes such as threshold effects and statistical discharge distributions, which are fundamental features of river dynamics. Despite their importance in quantitative geomorphology, such model formulations have been confronted with field data only in a limited number of cases. Here we investigate the behavior of stochastic- threshold incision models across the southeastern margin of the French Massif Central, which is characterized by significant relief and the regular occurrence of high-discharge events.

Previous talks:

Kristen Cook (GFZ Potsdam / 29 September 2022)

"Meet the next EGU-GM President and some extreme bedrock river science"

Sonia Silvestri (University of Bologna / 22 September 2022)

"Remote sensing and ecogeomorphology of coastal systems: difficulties and merits of being constantly at the edge of disciplines"

Sabin Zahirovic & Tristan Salles (University of Sydney / 16 June 2022)

"Importance of landscape dynamics on long-term sedimentation rates: a global scale perspective "

Phaedra Upton (GNS Science Dunedin / 16 June 2022)

"The Marlborough Fault System: a complex transition zone in central New Zealand illuminated by inherited structural and topographic anisotropy "

Anthony Dosseto (University of Wollongong / 16 June 2022)

"Rain, trees and erosion – new insights on old ideas"

Helen Dow (maiden name: Beeson) (ETH Zurich / 09 June 2022)

"Identifying causal links between tectonic processes and biodiversity in an orogenic wedge setting with a coupled landscape-biodiversity evolution model"

Eric Deal (ETH Zurich / 02 June 2022)

"Self formed channels with emergent channel width and sediment transport"

Oliver Korup (University of Potsdam / 19 May 2022)

"Mountainfall - Learning more about large landslides"

Pedro Val (Federal University of Ouro Preto / 12 May 2022)

"Widespread topographic transience in intraplate settings: it's "just" a lithologic effect"

Odin Marc (CNRS/GET Toulouse / 07 April 2022)

"What do we need to better constrain spatial and temporal occurrence of rainfall induced landslides"

Brent Goehring (Tulane University / 24 March 2022)

"Doing more with less: learning about processes from failures in beryllium-10 and carbon-14 surface exposure dating chronologies"

Ann Rowan (University of Sheffield / 17 March 2022)

"Rethinking ice-marginal moraines as a record of terrestrial paleoclimate change"

Charlotte Prud'homme (University of Lausanne / 10 March 2022)

"Long-term climate change in continental environments: An approach combining geochemistry and dating of continental carbonates"

Guy Paxman (Lamont-Doherty Earth Observatory / 03 March 2022)

"Subglacial landscapes in Greenland: Obscure(d) insights into past climates, environments, and ice sheets"

John Jansen (Czech Academy of Sciences / 24 February 2022)

"Geomorphic legacy of a fast-moving plate"

Leif Anderson (University of Utah / 17 February 2022)

"Making sense of chaos: debris-covered glacier landscapes in the face of climate change"

Sébastien Carretier (IRD and University of Toulouse / 02 December 2021)

"How can the movement of grains be linked to geomorphological transport laws (on long time scales)? "

Anne Bernhardt (Freie Universität Berlin / 25 November 2021)

"How fast are environmental signals recorded & for how long? Landscape response decoded from marine sediments"

Dirk Scherler (GFZ Postdam / 18 November 2021)

"Eroding the Garhwal Himalaya – deciphering climatic and tectonic controls with cosmogenic nuclides"

Katherine Huntington (University of Washington / 04 November 2021)

"Megamountains, megarivers, and megafloods: interactions of Earth surface processes & tectonics in the Eastern Himalaya How can the movement of grains be linked to geomorphological transport laws (on long time scales)?"

Sara Savi (Potsdam University / 28 October 2021)

"Effects of climate warming on slope instability and debris flow activity in high mountain regions"

Abigail Langston (Kansas State University / 21 October 2021)

"Beyond lithologic control of bedrock valley width: Characterizing the role of persistent valley cover in bedrock valley width development with examples from the field and the flume"

Cristián Escauriaza (Pontificia Universidad Catolica de Chile / 07 October 2021)

"Simulations of Antidunes in Supercritical Flow"

Andrew Christ (University of Vermont / 30 September 2021)

"Camp Century revisited: an ecosystem under the ice reveals Greenland’s warmer past"

Doug Jerolmack (University of Pennsylvania / 23 September 2021)

"Landscapes of glass"

Sean Willett (ETH Zurich / 16 September 2021)

"Nature’s Other Great Experiment in Landscape Evolution "

Anne Voigtländer (GFZ Potsdam / 25 June 2021)

"Optimal stress states for geomorphologists"

Laura Quick (University of Edinburgh / 17 June 2021)

"Production and dispersal of coarse sediment across the Indo-Gangetic Plains"

Jane L. Andersen (Aarhus University / 10 June 2021)

"Exploring erosion patterns beneath high-latitude ice sheets – case studies from Scandinavia and Greenland"

Giulia Sofia (University of Connecticut / 3 June 2021)

"Digital Analysis and Terrain Mapping. The way forward in geomorphology"

Seulgi Moon (University of California Los Angeles / 27 May 2021)

"Topographic stress influence on fractures, surface processes, and landscape evolution"

Tamara Pico (University of California Santa Cruz / 20 May 2021)

"In and out of the last ice age: Insights into the influence of glacial isostatic adjustment on landscape evolution in North America"

Benjamin Keisling (Lamont-Doherty Earth Observatory / 13 May 2021)

"Past as prologue: how archives help us predict the fate of Earth’s ice sheets and the future of our discipline"

Kelin Whipple (Arizona State University / 6 May 2021)

"Quantifying the Role of Climate in Landscape Evolution"

Simon Mudd (University of Edinburgh / 25 March 2021)

"If you don’t like the stream power law, wait until you get a load of what we do on hillslopes"

Roman DiBiase (PennState University / 18 March 2021)

"Morphodynamics of mixed soil-mantled and bare bedrock hillslopes"

Ajay Limaye (University of Virginia / 11 March 2021)

"Origin and evolution of river forms"

Karl Lang (Georgia Institute of Technology / 4 March 2021)

"Linking orogeny and orography in the Southern Alps of New Zealand"

Allison Pfeiffer (Western Washington University / 25 February 2021)

"Sediment supply controls river bed (in)stability in the Pacific Northwest"

Edwin Baynes (Loughborough University / 18 February 2021)

"Hard vs Soft: spatial variability in bedrock channel geometry driven by sediment availability"

Heather Viles (University of Oxford / 11 February 2021)

"Linking life and landscape: monitoring, mapping and modelling in biogeomorphology"

Gabor Domokos (Budapest University of Technology / 26 November 2020)

"Estimating mass loss from pebble shape"

Alison Duvall (University of Washington / 19 November 2020)

"Exploring the timing, triggering and spatial distribution of landslides along the Cascadia Subduction Zone"

Alex Whittaker & Mikael Attal (Imperial College London & University of Edinburgh / 12 November 2020)

"Faulting and landscapes - a tribute to Patience Cowie"

Joanmarie del Vecchio (Penn State University / 5 November 2020)

"Appalachian pasts, Arctic futures: permafrost landscape dynamics"

Susan Conway (CNRS Nantes / 8 October 2020)

"Sublimation as a geomorphic process on Mars"

Michele Koppes (University of British Columbia / 1 October 2020)

"Reading the story of climate change in the landscape: Sedimentary signatures of disappearing glaciers"

Jean Braun (GFZ Potsdam / 24 September 2020)

"Flow of southeastern Tibet across a steady-state topography"

John Armitage (IFPEN Paris / 17 September 2020)

"Reproducible landscapes"

The presentation can be found here

Georgie Bennett (University of Exeter / 2 July 2020)

"Hazardous landscapes: Towards landslide early warning in Nepal and the Philippines"

Fiona Clubb (Durham University / 25 June 2020)

"Creepy landscapes along the San Andreas fault"

Robert Hilton (Durham University / 18 June 2020)

"The shifting view of how mountain building and erosion impact the carbon cycle"

Liran Goren (Ben Gurion University of the Negev / 11 June 2020)

"Grainscape"

Anneleen Geurts (University of Bergen / 4 June 2020)

"Drainage integration in continental rifts"

Landscapes Live

was launched by Philippe Steer, Steffi Toffelde, Vivi Pedersen, Pierre Valla, Charles Shobe and Wolfgang Schwanghart during the Covid-19 epidemic