Loading of the San Andreas fault by flood-induced rupture of faults beneath the Salton Sea

The southern San Andreas fault has not experienced a large earthquake for approximately 300 years, yet the previous five earthquakes occurred at ∼180-year intervals. Large strike-slip faults are often segmented by lateral stepover zones. A Movement on smaller faults within a stepover zone could perturb the main fault segments and potentially trigger a large earthquake. The southern San Andreas fault terminates in an extensional stepover zone beneath the Salton Sea-a lake that has experienced periodic flooding and desiccation since the late Holocene. Here we reconstruct the magnitude and timing of fault activity beneath the Salton Sea over several earthquake cycles. We observe coincident timing between flooding events, stepover fault displacement and ruptures on the San Andreas fault. Using Coulomb stress models, we show that the combined effect of lake loading, stepover fault movement and increased pore pressure could increase stress on the southern San Andreas fault to levels sufficient to induce failure. We conclude that rupture of the stepover faults, caused by periodic flooding of the palaeo-Salton Sea and by tectonic forcing, had the potential to trigger earthquake rupture on the southern San Andreas fault. Extensional stepover zones are highly susceptible to rapid stress loading and thus the Salton Sea may be a nucleation point for large ruptures on the southern San Andreas fault. © 2011 Macmillan Publishers Limited. All rights reserved

The problem and promise of coproduction: Politics, history, and autonomy

Interest in coproduction has continued to grow since Elinor Ostrom introduced the concept to the development scholarship two decades ago. The idea that multiple actors often interact to coproduce public goods and services helped shift development thinking away from one-size-fits-all policy prescriptions based on free market principles to a more nuanced position that recognizes organizational and institutional diversity. However, while Ostrom’s concept of coproduction provides a useful starting point to think about how states and societies interact to deliver public goods and services, it fails to capture the complexity and significance of the process. The diverse scholarship that has extended and critiqued her work has provided a fuller picture. Yet, important gaps remain. The principal aim of this article is to fill some of these gaps and expand the boundaries of coproduction research and analysis. Drawing on qualitative research on water services and management in Ecuador, it focuses on two interrelated issues that are overlooked or underdeveloped in the existing literature. The first relates to the history of coproduction. The article shows that coproduction is more deeply rooted in capitalist development than commonly believed, and historical events have a significant bearing on contemporary politics. The second concerns autonomy. The essay shows that coproduction simultaneously promotes engagement with and autonomy from the state, and that this tension generates political struggle and change. More broadly, the article casts fresh light on the politics of public goods and services in the Global South, especially on the political impact of collective social participation in the process