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Kinematics of the Nicaraguan forearc from GPS geodesy
Author(s) -
Turner Henry L.,
LaFemina Peter,
Saballos Armando,
Mattioli Glen S.,
Jansma Pamela E.,
Dixon Timothy
Publication year - 2007
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2006gl027586
Subject(s) - forearc , geology , geodesy , kinematics , arc (geometry) , rotation (mathematics) , seismology , geometry , subduction , physics , tectonics , mathematics , classical mechanics
Campaign GPS data from a network in the Nicaraguan forearc show a strong component of arc‐parallel motion indicating northwest translation of a nearly rigid forearc sliver. Our measured mean velocity for forearc sites of 15.1 mm yr −1 agrees well with the arc‐parallel sliver motion predicted previously by DeMets (2001) derived from closure constraints on oblique convergence between the Cocos and Caribbean plates. The lack of a northeasterly oriented arc‐normal component of motion in forearc velocities indicates that there are complexities involved beyond a simple interpretation of sliver motion being driven by oblique convergence. The forearc is reasonably well‐fit by rigid rotation about an Euler pole with a rms misfit of residual velocities of 4.9 ± 2.6 mm yr −1 . Current motion of the forearc sliver relative to the stable Caribbean plate yields predominantly boundary parallel NW motion with boundary normal extension in the northwestern region averaging ∼5 mm yr −1 .