Schematic of the back-arc system of the southern Lau basin showing the change in subduction influence from north to south, substantially modified from Martinez et al. (2007). In the north (panel (a)), the ELSC is about 100 km from the Tofua arc. The melting regime for the back-arc is just slightly influenced by the slab flux that dominates the geochemical signals at the volcanic front of the arc. In the south (panel (b)), the VFR is only 45 km from the arc, and the back-arc melting system is strongly influenced by the subduction component.
Location of the cabled component of the National Science Foundation Ocean Observatories Initiative, including the Regional Scale Nodes and the companion system deployed as part of NEPTUNE Canada.
Media Type: Map
Investigator: Deborah Kelley
High-resolution (~ 5 m) bathymetry map of the Endeavour Integrated Study Site “bull’s-eye,”the Main Endeavour Field. The bathymetry was collected in 2005 as part of a joint project between the University of Washington, the W.M. Keck Foundation, and NEPTUNE Canada using the autonomous vehicle ABE. Venting in the southern cluster of chimneys, known as the Bastille complex, has been waning following the 1999–2000 intrusive event.
(a) The Endeavour Segment is located ~ 300 km off the coast of Vancouver Island and is a Canadian Marine Protected Area. It is bounded to the north by Middle Valley and West Valley, and to the south by the Cobb propagator. (b) The Main Endeavour Field was chosen as the Ridge 2000 Endeavour Integrated Study Site bull’s-eye because of its large and vigorously venting sulfide structures, because it was believed to be dominantly in a tectonic phase with significant seismic activity, and because it had a rich history of study by a diverse array of investigators.
Interdisciplinary lithosphere-to-hydrosphere representation of Endeavour Segment. This image shows the surface bathymetry underlain by multichannel seismic results from Carbotte et al. (2002) and Van Ark et al. (2007). For ease in viewing and graphical representation, the along-axis transect has been moved slightly to the east of the ridge axis; the white dashed line indicates the location of the along-axis survey line within the axial rift.
This clip shows the locations and magnitudes of earthquakes comprising the Endeavour 2005 swarm from 2/23/2005 to 3/5/2005, which initiated near West Valley and Endeavour Seamount and migrated to the south. The balls are color coded to magnitude with warmer colors corresponding to larger magnitude earthquakes (see color bar in the bottom left of corner). A running date and time is also shown near the right hand corner. These data were part of the Keck-UW data set (see Weekly et al., 2008 and Hooft et al., 2010).
Media Type: Animation
(A) The “Arches” area south of the Tubeworm Pillar location~one year after the 2005/2006 eruption(s), with diffuse vent flow, white staining, brachyuran crabs and Tevnia jerichonana tubeworm colonization at the base of eruptive lava remnants (2503 m depth). (B) Tevnia colonization following the 2005/6 eruption(s) in the TICA vent area with the outstretched Alvin manipulators imaging and collected in-situ fluid chemical data associated with this assemblage (2517 m depth).
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].
Compiled visualization of datasets from the East Pacific Rise (EPR) Integrated Study Site (ISS). At right, ship-based EM300 bathymetry (25-m resolution) shows the axial high between 9°46'N and 9°56'N [White et al., 2006]. A higher resolution bathymetry data set (5-m resolution) collected in 2001 by the autonomous underwater vehicle (AUV) ABE is overlain and shows greater details of the volcanic terrain [Fornari et al., 2004; Escartin et al., 2007].
Three-dimensional illustration of the melt region beneath the Siqueiros transform fault located at 8.5°N on the East Pacific Rise (mantle not to scale). The region of the mantle that is melting expands up to 100 km on either side of the East Pacific Rise ridge axis creating a large region from which melt is focused to the ridge. Gray arrows indicate plate motion, blue arrows mantle upwelling, and yellow arrows melt focusing.