Multibeam bathymetry and sidescan imaging of the Rivera Transform-Moctezuma spreading segment junction, northern East Pacific Rise: New constraints on Rivera-Pacific relative plate motion
|Author(s)||Bandy W1, Michaud F2, 3, Dyment Jerome4, Mortera Gutierrez C1, Bourgois J2, 3, Calmus T5, Sosson M6, Ortega Ramirez J, Royer J7, Pontoise B2, Sichler Bertrand8|
|Affiliation(s)||1 : Univ Nacl Autonoma Mexico, Inst Geofis, Mexico City 04510, DF, Mexico.
2 : UNAS UPMC CNRS IRD, Geosci Azur, Villefranche Sur Mer, France.
3 : EPN, Quito, Ecuador.
4 : Inst Phys Globe, CNRS, Paris, France.
5 : Univ Nacl Autonoma Mexico, Inst Geol, Hermosillo, Sonora, Mexico.
6 : Univ Nice Sophia Antipolis, Geosci Azur, Nice, France.
7 : CNRS Domaines Ocean, Brest, France.
8 : IFREMER, Brest, France.
|Source||Tectonophysics (0040-1951) (Elsevier), 2008-06 , Vol. 454 , N. 1-4 , P. 70-85|
|WOS© Times Cited||8|
|Keyword(s)||Plate motions, Plate boundary morphology, Mexico, Rivera plate, Rivera Transform, East Pacific Rise|
|Abstract||To better understand the recent motion of the Pacific plate relative to the Rivera plate and to better define the limitations of the existing Rivera-Pacific plate motion models for accurately predicting this motion, total-field magnetic data, multibeam bathymetric data and sidescan sonar images were collected during the BART and FAMEX campaigns of the N/O L'Atalante conducted in April and May 2002 in the area surrounding the Moctezuma Spreading Segment of the East Pacific Rise, located offshore of Manzanillo, Mexico, at 106 degrees 16'W, between 17.8 degrees N and 18.5 degrees N. Among the main results are: (1) the principle transform displacement zone of the Rivera Transform is narrow and well defined east of 107 degrees 15'W and these azimuths should be used preferentially when deriving new plate motion models, and (2) spreading rates along the Moctezuma Spreading Segment should not be used in plate motion studies as either seafloor spreading has been accommodated at more than one location since the initiation of seafloor spreading in the area of the Moctezuma Spreading Segment, or this spreading center is not a Rivera-Pacific plate boundary as has been previously assumed. Comparison of observed transform azimuths with those predicted by the best-fit poles of six previous models of Rivera-Pacific relative motion indicate that, in the study area, a significant systematic bias is present in the predictions of Rivera-Pacific motion. Although the exact source of this bias remains unclear, this bias indicates the need to derive a new Rivera-Pacific relative plate motion model.|