Woods Hole Oceanographic Institution

Juan Pablo Canales

»41. R2K Advances in Seismic Imaging
Oceanography, 2012

»40. R2K Seismic Studies
Oceanography, 2012

»39. Melt bodies off the EPR
Nature Geoscience, 2012

»38. JdF Plate: Gravity structure
G-cubed, 2011

»37. JdF Plate: Layer 2B structure
G-cubed, 2011

»36. Kane waveform tomography
GRL, 2010

»35. Kane Oceanic Core Complex
G-cubed, 2009

»34. Geophysical signatures of oceanic core complexes
GJI, 2009

»33. Accretion of the lower crust
Nature, 2009

»32. Faulting of the Juan de Fuca plate
EPSL, 2009

»31. Axial topography os the Galapagos Spreading Center
G-cubed, 2008

»30. Juan de Fuca Ridge flanks
G-cubed, 2008

»29. Seismic structure of oceanic core complexes
G-cubed, 2008

»28. Juan de Fuca Ridge: structure and hotspots
G-cubed, 2008

»27. Structure of the TAG segment, Mid-Atlantic Ridge
G-cubed, 2007

»26. Detachment faulting at TAG, Mid-Atlantic Ridge
Geology, 2007

»25. Structure of the Endeavour segment, Juan de Fuca Ridge
JGR, 2007

»24. Magma beneath Lucky Strike Hydrothermal Field
Nature, 2006

»23. Magma chamber of the Cleft segment, Juan de Fuca Ridge
EPSL, 2006

»22. Topography and magmatism at the Juan de Fuca Ridge
Geology, 2006

»21. Structure of the southern Juan de Fuca Ridge
JGR, 2005

»20. Sub-crustal magma lenses
Nature, 2005

»19. Constructing the crust at the Galapagos Spreading Center
JGR, 2004

»18. Atlantis core complex
EPSL, 2004

»17. Morphology of the Galapagos Spreading Center
G-cubed, 2003

»16. Crustal structure of the East Pacific Rise
GJI, 2003

»15. Plume-ridge interaction along the Galapagos Spreading Center
G-cubed, 2002

»14. Compensation of the Galapagos swell
EPSL, 2002

»13. Structure of Tenerife, Canary Islands
JVGR, 2000

»12. Underplating in the Canary Islands
JVGR, 2000

»11. Structure of the Mid-Atlantic Ridge (MARK, 23?20'N)
JGR, 2000

»10. Structure of the Mid-Atlantic Ridge (35?N)
JGR, 2000

»9. Structure of Gran Canaria, Canary Islands
J. Geodyn., 1999

»8. Structure of overlapping spreading centers in the MELT area
GRL, 1998

»7. Crustal thickness in the MELT area
Science, 1998

»6. The MELT experiment
Science, 1998

»5. The Canary Islands swell
GJI, 1998

»4. Morphology of the Galapagos Spreading Center
JGR, 1997
»3. Faulting of slow-spreading oceanic crust
Geology, 1997

»2. Flexure beneath Tenerife, Canary Islands
EPSL, 1997

»1. Elastic thickness in the Canary Islands
GRL, 1994


Canales, J.P., J.J. Da?obeitia, R.S. Detrick, E.E.E. Hooft, R. Bartolome and D.F. Naar, Variations in axial morphology along the Galapagos spreading center and the influence of the Galapagos hotspot, J. Geophys. Res., 102, 27,341-27,354, 1997



The Galapagos Spreading Center (GSC) is marked by systematic changes in axial morphology between the Inca FZ at 85.5?W and the 95.5?W propagator. We analyze these changes using new swath bathymetry and magnetic data acquired aboard the B.O. Hesperides during the Galapagos'96 experiment. Within ~350 km of the Galapagos hotspot the ridge axis is associated with an EPR-like axial high. At increasing distance from the hotspot the axial high broadens and deepens forming a distinctive transitional axial morphology (TAM). The axis in this transitional region is typically a broad zone (~20 km wide) consisting of very rough volcanic and fault-generated topography. West of 95?W, this TAM evolves into a 20-40 km wide, 400-1500 m deep axial valley typical of the slow spreading MAR. There is not an abrupt change from axial high to rift valley along the GSC, but a distinct TAM which occurs over a distance of ~200-300 km along- axis, and is accompanied by a gravity-estimated crustal thickening of >1-2 km. The boundary between an axial high and this TAM is quite abrupt, and occurs along a segment less than 9 km long. These changes in axial morphology are primarily caused by variations in magma supply along the GSC due to the entrainment and dispersal of plume mantle from the Galapagos hotspot. However, the changes in morphology are not symmetric about the Galapagos FZ at 91?W. The axial high topography extends further east of the 91?W FZ than to the west, and the rift valley which develops west of 94?W is not found at comparable distances along the GSC east of the hotspot. Axial depth variations are also asymmetric across the 91?W FZ. This asymmetry in both morphology and axial depth variation is attributed to a full spreading rate increase along the GSC from 46 mm/yr at 97?W to 64 mm/yr at 85?W. Off-axis depth changes are symmetric about the 91?W FZ and suggest that 15-40% of on-axis depth variation is dynamically supported.

© Woods Hole Oceanographic Institution
All rights reserved