Imaging volcanic systems via multi-scale electromagnetic imaging

Electromagnetic imaging provides a wealth of information about the structure, composition, and processes within volcanic systems. While deep-sensing techniques such as magnetotellurics (MT) focus on the magmatic system, airborne electromagnetics (AEM) is capable of mapping active hydrothermal cells and their alteration products, faults, lava flows, water-saturated zones, and perched aquifers. All these components are important to improving volcanic hazard assessments and understanding magmatic and hydrothermal processes at work beneath active volcanoes. We present two recent AEM studies at Yellowstone and Klauea volcanoes. At Yellowstone, AEM studies map conduits that connect heat and deep thermal fluids to surface thermal features. We further identify a distinct electrical signature over hydrothermal domes which sheds light on their formation and potential for hydrothermal explosions. At Klauea, AEM models image the structural backbone of this complex volcano, including elevated conductivity over the summit lava lake, along faults accommodating collapse of the volcano's south flank, and along both the flanking rift zones that have sourced lavas from fissure eruptions over the past two centuries. Work at both volcanoes is ongoing of merging AEM and MT data sets to image these systems from the base of the crust to the surface.