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Accueil du site > Français > Les annonces de séminaires et thèses > Séminaire de Jean BRAUN (ISTerre Grenoble & CIFAR Canada)

Séminaire de Jean BRAUN (ISTerre Grenoble & CIFAR Canada)

Date : 19 avril 2013, 10 h 30

Titre : Deep mantle flow, river incision and Milankovitch cycles.

Lieu : Salle de Conférences de l’OSUR (Bât. 14 B, RdC)

Résumé :

We have recently developed a new algorithm to solve the basic stream power equation, which governs channel incision and landscape evolution in many geomorphic settings (Braun and Willett, 2013). The algorithm is highly efficient because computation time increases linearly with the number of points used to discretize the landscape and is ideally suited to parallelization. It is also unconditionally stable because it uses an implicit scheme for the time integration of the landscape evolution equation, which means that large time steps can be used without sacrificing accuracy. In this seminar, I will briefly present this new algorithm and apply it to three different case studies. Firstly, I will demonstrate how a high resolution geochemical record from the Bengal Fan can be explained by the delayed erosional response of the Himalayas to climate variations at Milankovitch periods. I will then demonstrate why dynamic topography can be efficiently eroded, despite the low slope it generates and illustrate this point by two examples, one concerning a recent wave of dynamic topography that affected the Colorado Plateau and one explaining the rapid pulse of sedimentation that accompanied the dynamic uplift of the South African craton in the Cretaceous.