Landscapes Live

Spring 2026 Seminar Series

Thursday, 5 March 2026 at 16:00 CEST

Tjalling de Haas (University of Utrecht, The Netherlands)

Unravelling the dynamics of debris flows on Earth, Mars, and beyond

Understanding the dynamics of debris flows is important for mitigating hazards on Earth, but at the same time helps us reconstruct the present and past environmental conditions on planets, moons, and asteroids. In this talk I will summarize how we have used physical-scale experiments to 1) unravel controls on debris-flow dynamics, deposit morphology, erosion processes, and fan avulsion mechanisms, 2) decipher how sublimating ices can fluidize debris flows in the absence of liquid water in the thin atmospheres of extra-terrestrial bodies recreated in large vacuum chambers, and 3) determine how gravity affects the dynamics and mobility of debris flows under reduced and enhanced gravity, simulated with parabolic flights. On top of giving insights in the dynamics of debris flows on Earth and beyond, this talk will showcase the power of physical-scale experiments in understanding planetary surfaces, particularly when combined with field observations, numerical modelling, and remote sensing. 

Thursday, 12 March 2026 at 16:00 CEST

Emma Lodes (Arizona State University, USA)

Thursday, 19 March 2026 at 16:00 CEST

Tingan Li (Cornell University, USA)

Thursday, 26 March 2026 at 16:00 CEST

Ian Delaney (University of Lausanne, Switzerland)

Thursday, 9 April 2026 at 16:00 CEST

Chuanqi He (Sun Yat-Sen University, China)

Persistent water cycles after Martian floods

Early Mars experienced a wet climate. Low-lying impact craters gathered water, forming lakes. When water levels surpass the crater boundary, lakes can breach and trigger floods that release large volumes of high-energy water. Whether canyon erosion reflects a single breaching flood or sustained post-flood outflow remains unresolved, despite its implications for constraining early Martian water cycles and the potential for lakes to support life. By combining topographic observations on Mars with flood erosion constraints on Earth, we demonstrate the majority of open-basin lakes on Mars (146 out of 200) experienced post-flood outflows (i.e., continued water flow after the initial breaching flood), with total water volumes 55 times greater than initial floods. Such volumes required tens to hundreds of outflow events, indicating that early Mars maintained persistent hydrological cycles over cumulative timescales of millions of years.

Thursday, 16 April 2026 at 16:00 CEST

Tristram Hales (Cardiff University, UK)

The Sediment Cascades of Large Continental Earthquakes

In steep mountainous landscapes, hillslope processes are often described as being coupled to incision driven by rivers. The rate of hillslope sediment generation by diffusive and landsliding processes occur at rates that vary with topography. Earthquakes modify this coupled system by stochastically generating landslide sediment closer to mountain ridges and major fault networks. In actively uplifting orogens these stochastic processes may generate up to 50% of the overall hillslope sediment budget. Earthquake triggered sediment mostly takes the form of landslide deposits that have a patchy distribution, commonly away from the fluvial network or in low order catchments where fluvial processes are weaker. This talk will explore our current understanding of the processes governing how and at what timescales sediment generated by earthquakes impacts orogens. Evidence from the sediment cascades of multiple recent earthquakes suggests that at the decadal-centennial timescale, a small proportion (usually less than half) of the sediment generated by earthquakes is exported outside of the orogen and rates of sediment export are lower for smaller earthquake events. Where cascading sedimentary sequences have been examined in detail, sediment export rates are strongly linked to the debris flows. The fluvial system, which cannot efficiently transport coarse landslide sediment is commonly perturbed by earthquake sediment for many hundreds to possibly thousands of year.  Earthquake sediment preserved on high mountain hillslopes may generate a legacy of large and hazardous debris flows that can extend the timing and impact of cascading processes. However, recent large earthquakes have all differed in the frequency and magnitude of their post-earthquake sediment fluxes reflecting gaps in our understanding of how hillslope process linkages drive the cascading effects of earthquakes. 

Thursday, 23 April 2026 at 16:00 CEST

Kevin Norton (University of Tübingen, Germany)

Thursday, 30 April 2026 at 16:00 CEST

Raquel Portes (University of Northern British Columbia, Canada)

Thursday, 14 May 2026 at 16:00 CEST

Ken Ferrier (University of Wisconsin-Madison, USA)

Thursday, 21 May 2026 at 16:00 CEST

Amy East (US Geological Survey)

Understanding physical landscape effects of climate change: how much do we know, and what are we doing about it?

Today, climate change is affecting virtually all terrestrial and nearshore settings. How well do we understand the physical landscape effects, and how have planning and economic sectors responded so far? This presentation will discuss the challenges of identifying and measuring climate-driven physical landscape responses to modern warming and its associated hydrologic shifts. Challenges include short, incomplete data records, land use and seismicity masking climatic effects, biases in data availability and resolution, signals dominated by individual extreme events, and signal attenuation in sedimentary systems. Despite such challenges, the scientific community has important opportunities to learn from historical and paleo data, to select especially informative study sites, and to learn also from studies producing null results. Fortunately, our knowledge base in these subjects is growing rapidly, leading to substantial progress in protecting communities physically and financially. Knowing that climate-driven sedimentary and geomorphic changes influence human health and safety, infrastructure, water–food–energy security, and economies, we will examine examples of how those effects are being incorporated into planning and design today.

Thursday, 28 May 2026 at 16:00 CEST

Ariadna Canari (ICM Barcelona, Spain)

Thursday, 4 June 2026 at 16:00 CEST

Benjamin Campforts (VU Amsterdam, the Netherlands)

Thursday, 11 June 2026 at 16:00 CEST

Anna Maartje de Boer (Wageningen University & Research, the Netherlands; University of Cologne, Germany)

Imaging luminescence signals as tracers of sediment transport and feldspar weathering

Luminescence techniques are conventionally applied to date the burial age of sediments. With time, natural environmental radiation causes electrons to become trapped in defects within the crystal lattices of natural quartz and feldspar minerals, the main constituents of sand. The progressive accumulation of this trapped charge forms the fundamental basis of luminescence dating, allowing the time elapsed since light exposure to be estimated. A key assumption in luminescence dating is that the trapped charge is completely reset or bleached prior to burial. This bleaching can occur when sediments are exposed to sunlight during transport so that previously accumulated charge is removed. If the signal is not fully reset, i.e. incomplete or poor bleaching, residual charge remains in the crystal lattice and can lead to age overestimation. While this poses a challenge for dating the sediment, the bleaching process itself provides valuable information on sediment dynamics during transport. The degree and variability of bleaching reflect the conditions and duration of light exposure during transport and deposition. In this seminar, I will present my PhD research on luminescence-based sediment tracing, which exploits differences in luminescence signal resetting rates between multiple feldspar signals to get insight into sediment transport histories (of nourishments) in the dynamic Ameland tidal inlet of the Dutch Wadden Sea. In Dutch practice, nourishments are dredged sand from the North Sea and deposited near- or on-shore to replenish sand volumes lost due to coastal erosion. I will then introduce my postdoctoral research on weathering-induced changes in feldspar luminescence, where EMCCD-based luminescence imaging enables measurements on rock slabs and weathered mineral surfaces. By quantifying luminescence characteristics that evolve during mineral alteration, this work aims to develop a feldspar-based luminescence proxy for weathering intensity. The outcomes can potentially be applied to quantify weathering rates and mineral alterations within Earth's Critical Zone.

Thursday, 18 June 2026 at 16:00 CEST

Jane Willenbring (Stanford University, USA)

Living on the Edge: Landscapes Edging Toward Badland Topography

The lack of soil on some hillslopes, such as in badland topography, requires a mismatch in the rates of soil production and soil erosion today or in the past. Soil blanketing most of Earth attests to the likelihood of some balancing mechanism between soil production and erosion. However, it seems possible - even probable - that rapidly changing natural environments and land and water use amplification by humans might tip landscapes across a threshold where soil replenishment is not the norm. If we find ourselves in such a time today or in the future, how can cosmogenic nuclides that often rely on steady-state assumptions still help Earth scientists quantify earth-surface change? What clues would cosmogenic nuclides and soil chemistry provide that might indicate what kinds of thresholds have been crossed?