Variations in axial magma lens properties along the East Pacific Rise (9°30′N–10°00′N) from swath 3-D seismic imaging and 1-D waveform inversion
Canales, J. Pablo
Carbotte, Suzanne M.
Nedimovic, Mladen R.
Mutter, John C.
MetadataShow full item record
We use three-dimensional multistreamer seismic reflection data to investigate variations in axial magma lens (AML) physical properties along the East Pacific Rise between 9°30′N and 10°00′N. Using partial-offset stacks of P- and S-converted waves reflecting off the top of the AML, we image four 2–4 km long melt-rich sections spaced 5–10 km from each other. One-dimensional waveform inversion indicates that the AML in a melt-rich section is best modeled with a low Vp (2.95–3.23 km/s) and Vs (0.3–1.5 km/s), indicating >70% melt fraction. In contrast, the AML in a melt-poor section requires higher Vp (4.52–4.82 km/s) and Vs (2.0–3.0 km/s), which indicates <40% melt fraction. The thicknesses of the AML are constrained to be 8–32 m and 8–120 m at the melt-rich and -poor sites, respectively. Based on the AML melt-mush segmentation imaged in the area around the 2005–2006 eruption, we infer that the main source of this eruption was a 5 km long section of the AML between 9°48′N and 51′N. The eruption drained most of the melt in this section of the AML, leaving behind a large fraction of connected crystals. We estimate that during the 2005–2006 eruption, a total magma volume of 9–83 × 106 m3 was extracted from the AML, with a maximum of 71 × 106 m3 left unerupted in the crust as dikes. From this, we conclude that an eruption of similar dimensions to the 2005–2006, one would be needed with a frequency of years to decades in order to sustain the long-term average seafloor spreading rate at this location.
Author Posting. © American Geophysical Union, 2014. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research: Solid Earth 119 (2014): 2721–2744, doi:10.1002/2013JB010730.
Showing items related by title, author, creator and subject.
Christeson, Gail L. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1994-02)This thesis is concerned with understanding how oceanic crust is emplaced at mid-ocean ridges. The emphasis is upon fast-spreading ridges, and the use of seismic techniques to image the uppermost several hundred meters ...
Interrelationships between vent fluid chemistry, temperature, seismic activity, and biological community structure at a mussel-dominated, deep-sea hydrothermal vent along the East Pacific Rise Lutz, Richard A.; Shank, Timothy M.; Luther, George W.; Vetriani, Costantino; Tolstoy, Maya; Nuzzio, Donald B.; Moore, Tommy S.; Waldhauser, Felix; Crespo-Medina, Melitza; Chatziefthimiou, Aspassia D.; Annis, Eric R.; Reed, Andrew J. (National Shellfisheries Association, 2008-03)In April 1991, submarine volcanic eruptions initiated the formation of numerous hydrothermal vents between 9°45′ and 9°52′N along the crest of the East Pacific Rise (EPR). Dramatic changes in biological community structure ...
Recent seismic studies at the East Pacific Rise 8°20'–10°10'N and Endeavour Segment : insights into mid-ocean ridge hydrothermal and magmatic processes Carbotte, Suzanne M.; Canales, J. Pablo; Nedimovic, Mladen R.; Carton, Helene; Mutter, John C. (The Oceanography Society, 2012-03)As part of the suite of multidisciplinary investigations undertaken by the Ridge 2000 Program, new multichannel seismic studies of crustal structure were conducted at the East Pacific Rise (EPR) 8°20'–10°10'N and Endeavour ...