Landscapes Live

EGU-GM Online Seminars in Geomorphology

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 (Winter-Spring):

19 May 2022 - Oliver Korup (University of Potsdam) "Mountainfall – Learning more about large landslides"

→ To register: https://bristol-ac-uk.zoom.us/meeting/register/tJckc-qurzwjGtMD8i7zmjCl3RA7pSkc6_BC

Abstract: Landslide research has become a rapidly growing field of modern geomorphology, and highlighted many feedbacks that extend beyond processes on hillslopes. Most models concerning the relevance of landslides in landscapes draw on increasingly detailed and systematic catalogues of frequent slope failures in active mountain belts. In contrast, the bulk of research concerned with landslide prediction relies on small training data sets and study areas to identify hillslope portions that are most prone to failure.

Either way, infrequent and large landslides that move millions of cubic metres have mostly eluded such systematic analyses except for volcanic and submarine settings. Yet the study of large terrestrial landslides offers fresh insights and challenges for models of slope stability, landscape evolution, hazard appraisals, and ecological disturbance. Most legacy of individual large landslides tends to reside much longer in landscapes than that of smaller landslides, and can involve lowered mountain peaks and drainage divides; redistributed crustal loads; unroofed magma chambers; blocked or diverted rivers; infilled valleys and inner gorges; glacier surges; outburst, tsunami, and turbidite deposits; and changes to habitats and biodiversity.

While these impacts may be preserved variably over several tens to millions of years, attempts at hind- or forecasting large landslides have been few, if not outnumbered by speculations about their recurrence. Seismology has opened new doors for detecting and monitoring large slope failures systematically, and augments the wealth of local case studies that have produced a heterogeneous array of data. In this presentation I review an updated global inventory of Earth’s largest terrestrial landslides, and show how incorporating topographic and age constraints can meaningfully improve probabilistic models of their size distribution and geometric scaling. These models pave the way for estimating the return periods of giant slope failures, associated erosion rates, hazard and risk levels, and appraising any potential response to climate change.

02 June 2022 - Eric Deal (ETH Zurich) "Title TBA"

→ To register: link

Abstract:

09 June 2022 - Helen Dow (maiden name: Beeson) (ETH Zurich) "Identifying causal links between tectonic processes and biodiversity in an orogenic wedge setting with a coupled landscape-biodiversity evolution model"

→ To register: link

Abstract: Landscapes and their associated ecosystems coevolve over geologic time. Correlative approaches have elucidated the importance of topographic diversity and tectonic history but have not identified specific causal links between tectono-geomorphic processes and biodiversity metrics. To address this issue, we coupled the numerical landscape evolution model DAC (Divide and Capture) with a mechanistic model for biodiversity that simulates evolution, dispersal, allopatric speciation, and extinction to develop hypothetical biological signatures of different functional groups to a variety of landscape histories. In our coupled model, DAC-Bio, suitable habitat for aquatic species is defined as the channel network with limitations on discharge and dispersal confined to the network. Suitable habitat for terrestrial species is defined using a combination of elevation, slope, aspect, and discharge which are measured at sub-grid scale from the simulated landscape and meant to represent more complex physical parameters such as temperature, precipitation, soil properties, and hydrologic environment. In addition to habitability requirements, species are assigned evolution characteristics (rate of adaptation and draw toward the surrounding population mean), dispersal characteristics (rate and ability to cross geographic barriers), and speciation rate (isolation time needed to form new species). We test how horizontal advection characteristic of mountain ranges formed as orogenic wedges influences the spatial and temporal patterns of species richness and species’ range sizes for both aquatic and terrestrial organisms. We find that horizontal advection promotes ongoing reorganization of the drainage network with stream capture occurring from small basins to large basins on the pro-wedge side of the orogenic wedge and from pro-wedge to retro-wedge basins. Advection promotes movement of terrestrial species up the pro-wedge side of the mountain range toward the main divide, and river captures promote geographic transfer of both terrestrial and aquatic species from the pro-wedge side of the mountain range to the retro-wedge side. These processes leave distinct biological signatures in diversification rates and species richness.


16 June 2022 - Anne Guyez (University of Toulouse) "How it glows tells how it flows: insights on sediment transfer in braided river from feldspar single-grain luminescence pIRIR analysis in (Rakaia and Waimakariri braided rivers, Aotearoa, New Zealand) and numerical simulations"

→ To register: link

Abstract:

Postponed - Stéphane Bonnet (University of Toulouse) "Imprint of landscape dynamics on the luminescence of fluvial sediments (Rangitikei River, New Zealand)"

Abstract: The luminescence of quartz and feldspars is commonly used for burial dating Quaternary sediments (e.g. OSL and IRSL methods) however several studies have shown in recent years that luminescence can also be used for tracing Earth’s surface processes. In this seminar I will illustrate how surface processes impact the distribution of luminescence signals of fluvial sediments. I will take as an example the case of the Rangitikei River where we have acquired over the last few years a large database of luminescence measurements carried out at the single-grain scale in fluvial terraces and modern sediments. I will show in particular that the distribution of the signals reflects the combined effect of two main processes whose relative influence changes over time and space in relation to landscape dynamics: on one hand the input of bedrock grains to the river and on the other hand the longitudinal bleaching (zeroing) of the signal during transport. I will also discuss the consequences in terms of uncertainty on the luminescence dating of terraces.

Postponed - - Kate Leary (New Mexico Tech)


Previous talks:

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

Pedro Val

Abstract: Intraplate settings far from tectonic plate boundaries are rife with geomorphic features indicative of topographic transience. Paleovalleys, wind gaps, complex turns and shapes of river networks, river captures, asymmetric drainage divides, knickpoints, the list goes on. Yet, the triggers are hard to pinpoint. The usual mechanisms invoked as triggers of these features are intraplate tectonism (i.e. neotectonics), dynamic topography, or climatic oscillations.

These landscapes typically contain neighboring hydrographic basins that flow to the same baselevel and over similar or even the same rocks but have different mean elevations and asymmetric drainage divides. Explaining such areas as a function of changes in external boundary conditions (i.e. reactivated structures or climate) over such small spatial scales would require a perfect spatiotemporal combination of events, which is conceptually/theoretically unsatisfying.

In this presentation, I will demonstrate how the exhumation of just one lithology of different resistance to erosion may provide a one-size-fits-all mechanism to explain many of the seemingly unrelated transient geomorphic features observed in intraplate settings, even in areas far from lithologic contacts. This mechanism requires no change in external forcing, is likely to repeat itself over geologic time, and likely cause systematic and dynamic changes in river network shapes, topography, and erosion rates. The importance of this mechanism goes beyond the understanding of landscape evolution. Changing network shapes back and forth is a recipe for shuffling the inhabiting biota over geologic time and, therefore, a potential pump of biodiversity.