Cross-section of the East Pacific Rise axis between 9°49'N and 9°51'N showing relocated microearthquake locations (grey dots) from 2003-2004 [Waldhauser & Tolstoy, 2011] and inferred associated structure of hydrothermal circulation (figure after Tolstoy et al. ). Sites of up-flow and inferred down-flow are high permeability, whereas the central cracking zone is lower permeability [Crone et al., 2011]. The blue shading in the upper crust indicates an inferred thermal gradient based on vent temperature data [Scheirer et al., 2006, Tolstoy et al., 2008]. The temperature gradient may develop over a decade of localized down-flow, leading to the relative cooling of vents closest to the recharge site and warming of vents further away. Red lenses show inferred AMC locations (depth from Kent et al., ), with a possible break implied (yellow zone) based on a gap in the seismicity and a change in diffuse vent chemistry in this area along-axis [Von Damm and Lilley, 2004]. Hydrothermal vents are labeled.
Media Type: Illustration
Investigator: Maya Tolstoy