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Perturbation of earth surface systems by rare events (co-organized)
Convener: Kristen Cook  | Co-Conveners: Maarten Lupker , Sean Gallen , Christoff Andermann 
 / Mon, 24 Apr, 15:30–17:00
 / Attendance Mon, 24 Apr, 17:30–19:00

Rare large events, such as earthquakes, extreme storms, wildfires, or volcanic eruptions, can have cascading impacts on Earth surface processes. They can perturb Earth’s surface systems, trigger additional secondary effects, and impact processes for years to decades, or even millennia following the initial event. Strong shaking during earthquakes can cause changes of rock properties that influence slope stability as well as the hydrological conductivity of the subsurface for years following the earthquake. Large storms and earthquakes can trigger extensive landsliding, overwhelming entire landscapes with sediments and changing both sediment and weathering fluxes. Large landslides may cause long-term changes in hillslope-channel coupling and can act as sediment sources for hundreds of years, while large landslide dams can influence fluvial morphology and processes for up to tens of thousands of years. Volcanic eruptions cover large areas in ash, altering biological and erosional processes and can even impact weather systems on a continental to global scale. Wildfires severely affect vegetation in addition to baking the upper soil layers, removing protective cover and changing hydrological infiltration capacity. Human activities, such as road construction and deforestation can also reach dimensions that change natural fluxes and cycles severely, sometimes even irreversibly.
The long term responses of such events in landscapes often last several years or longer and even might outstrip the immediate co-event impact in their magnitude. Over time, event-perturbed processes and systems restore to background conditions, and the recovery process and transient timescales of different systems, e.g. weathering and sediment fluxes, can provide particularly valuable insights into the generalities of landscape evolution. However such events and their lingering effects are often not included in models and especially their long-term contribution to landscape development is still poorly understood. We welcome contributions focusing on a wide range of rare events and their associated perturbation of earth surface systems. We are particularly interested in exploring the lingering effects and their long-term impacts as well as the eventual recovery to an initial state. Field-based, experimental, theoretical, and computational contributions are all welcome.