Explosive super-eruptions from large-volume, shallow magma systems lead to enormous and devastating pyroclastic flows, the formation of gigantic collapse calderas, and deposition of volcanic ash over continent-sized areas. Recognition that future eruptions from these “supervolcanoes” will undoubtedly have severe impacts on society—and perhaps on life itself—has led to recent public and media interest. Should we be concerned about an imminent super-eruption? The answer to this question requires an understanding of past eruption events. In this issue, geoscientists investigating ancient supervolcanoes provide insight into the processes and the time required to generate large volumes of eruptible magma, the monitoring of a youthful system, and super-eruption processes and consequences.
October 2013 - Nitrogen and Its (Biogeoscosmo) Chemcial Cycling
The differentiation of our planet and formation of the continental crust, and its underlying mantle lithosphere, are in large part the result of magmatic processes at convergent margins. These magmatic processes are important to issues of societal interest such as the evolution of life, mineral and energy deposits, volcanic and fault hazards, and long-term climate change. Magmatism in oceanic and continental convergent arcs is not temporally or spatially steady-state, rather it occurs in pulses and lulls. The articles in this issue explore the tempo of magmatism as recorded in the rock record, investigate the causes of high-volume events in subduction-related magmas, and provide an overview of recently developed models to explain episodic behavior in subduction magmatism.