Plate Coupling and Strain Partitioning in the Northeastern Caribbean

SUMMARY The northeastern Caribbean provides a natural laboratory to investigate strain partitioning, its causes and its consequences on the stress regime and tectonic evolution of a subduction plate boundary. Here, we use GPS and earthquake slip vector data to produce a present-day kinematic model that accounts for secular block rotation and elastic strain accumulation, with variable interplate coupling, on active faults. We confirm that the oblique convergence between Caribbean and North America in Hispaniola is partitioned between plate boundary parallel motion on the Septentrional and Enriquillo faults in the overriding plate and plateboundary normal motion at the plate interface on the Northern Hispaniola Fault. To the east, the Caribbean/North America plate motion is accommodated by oblique slip on the faults bounding the Puerto Rico block to the north (Puerto Rico subduction) and to the south (Muertos thrust), with no evidence for partitioning. The spatial correlation between interplate coupling, strain partitioning and the subduction of buoyant oceanic asperities suggests that the latter enhance the transfer of interplate shear stresses to the overriding plate, facilitating strike-slip faulting in the overriding plate. The model slip rate deficit, together with the dates of large historical earthquakes, indicates the potential for a large (M w7.5 or greater) earthquake on the Septentrional fault in the Dominican Republic. Similarly, the Enriquillo fault in Haiti is currently capable of a M w7.2 earthquake if the entire elastic strain accumulated since the last major earthquake was released in a single event today. The model results show that the Puerto Rico/Lesser Antilles subduction thrust is only partially coupled, meaning that the plate interface is accumulating elastic strain at rates slower than the total plate motion. This does not preclude the existence of isolated locked patches accumulating elastic strain to be released in future earthquakes, but whose location and geometry are not resolvable with the present data distribution. Slip deficit on faults from this study are used in a companion paper to calculate interseismic stress loading and, together with stress changes due to historical earthquakes, derive the recent stress evolution in the NE Caribbean.

[1]  T. Dixon,et al.  GPS measurements across the Northern Caribbean Plate Boundary Zone: Impact of postseismic relaxation following historic earthquakes , 1998 .

[2]  P. Mann,et al.  Toward an integrated understanding of Holocene fault activity in western Puerto Rico: Constraints from high-resolution seismic and sidescan sonar data , 2005 .

[3]  D. Larue,et al.  Extension and transtension in the plate boundary zone of the northeastern Caribbean , 1991 .

[4]  James R. Rice,et al.  Chapter 20 Fault Stress States, Pore Pressure Distributions, and the Weakness of the San Andreas Fault , 1992 .

[5]  S. Stein,et al.  Is there a northern Lesser Antilles forearc block? , 2006 .

[6]  D. Wald,et al.  Active tectonics of the north-central Caribbean: Oblique collision, strain partitioning, and opposing subducted slabs , 1998 .

[7]  C. Demets,et al.  Deformation of Jamaica and motion of the Gonâve microplate from GPS and seismic data , 2007 .

[8]  C. Scholz,et al.  On the mechanism of seismic decoupling and back arc spreading at subduction zones , 1995 .

[9]  P. Molnar,et al.  Tectonics of the Caribbean and Middle America Regions from Focal Mechanisms and Seismicity , 1969 .

[10]  Paul Mann,et al.  Strain partitioning and fault slip rates in the northeastern Caribbean from GPS measurements , 2002 .

[11]  A. Mauffret,et al.  Geological interpretation of combined Seabeam, Gloria and seismic data from Anegada Passage (Virgin Islands, north Caribbean) , 1990 .

[12]  L. Parson,et al.  Accretionary margin of north-western Hispaniola : morphology, structure and development of part of the northern Caribbean plate boundary , 1992 .

[13]  J. Dieterich.  Time-dependent friction and the mechanics of stick-slip , 1978 .

[14]  P. Bernard,et al.  Subduction and seismic hazard in the northern Lesser Antilles: Revision of the historical seismicity , 1988 .

[15]  G. Suárez,et al.  Muertos Trough subduction—microplate tectonics in the northern Caribbean? , 1985, Nature.

[16]  Kelin Wang,et al.  Thermal constraints on the zone of major thrust earthquake failure: The Cascadia Subduction Zone , 1993 .

[17]  W. Ellsworth,et al.  Fault healing inferred from time dependent variations in source properties of repeating earthquakes , 1995 .

[18]  Paul Mann,et al.  Oblique collision in the northeastern Caribbean from GPS measurements and geological observations , 2002 .

[19]  Robert McCaffrey,et al.  Block kinematics of the Pacific-North America plate boundary in the southwestern United States from inversion of GPS, seismological, and geologic data , 2005 .

[20]  É. Calais,et al.  Geodetic observations of interseismic strain segmentation at the Sumatra Subduction Zone , 1997 .

[21]  R. Mccaffrey.  Oblique plate convergence, slip vectors, and forearc deformation , 1992 .

[22]  Hiroo Kanamori,et al.  Seismic coupling and uncoupling at subduction zones , 1983 .

[23]  P. Mann,et al.  Neotectonics of southern Puerto Rico and its offshore margin , 2005 .

[24]  P. Tapponnier,et al.  Slip Partitioning by Elastoplastic Propagation of Oblique Slip at Depth , 2003, Science.

[25]  J. Dolan,et al.  Structure and tectonics of the upper Cenozoic Puerto Rico-Virgin Islands carbonate platform as determined from seismic reflection studies , 1998 .

[26]  A. Chemenda,et al.  Strain partitioning and interplate friction in oblique subduction zones: Constraints provided by experimental modeling , 2000 .

[27]  R. Jarrard.  Relations among subduction parameters , 1986 .

[28]  Jian Lin,et al.  Stress interaction between subduction earthquakes and forearc strike‐slip faults: Modeling and application to the northern Caribbean plate boundary , 2004 .

[29]  P. Mann,et al.  Neotectonics of the Caribbean , 1984 .

[30]  T. Dixon,et al.  Neotectonics of Puerto Rico and the Virgin Islands, northeastern Caribbean, from GPS geodesy , 2000 .

[31]  P. Mann,et al.  Reconnaissance study of Late Quaternary faulting along Cerro Goden fault zone, western Puerto Rico , 2005 .

[32]  G. Christeson,et al.  Deep structure of an island arc backstop, Lesser Antilles subduction zone , 2003 .

[33]  T. Dixon,et al.  GPS geodetic constraints on Caribbean‐North America Plate Motion , 2000 .

[34]  B. Andrews,et al.  New seafloor map of the Puerto Rico trench helps assess earthquake and tsunami hazards , 2004 .

[35]  É. Calais,et al.  Coulomb stress evolution in Northeastern Caribbean over the past 250 years due to coseismic, postseismic and interseismic deformation , 2008 .

[36]  P. Tapponnier,et al.  Arc parallel extension and localization of volcanic complexes in Guadeloupe, Lesser Antilles , 2002 .

[37]  G. Burr,et al.  Paleoseismicity of the North American-Caribbean plate boundary (Septentrional fault), Dominican Republic , 1993 .

[38]  Neotectonics and subsidence of the northern Puerto Rico–Virgin Islands margin in response to the oblique subduction of high-standing ridges , 2005 .

[39]  L. Ruff.  Do trench sediments affect great earthquake occurrence in subduction zones? , 1989 .

[40]  É. Calais,et al.  From transtension to transpression along the northern Caribbean plate boundary off Cuba: implications for the Recent motion of the Caribbean plate , 1991 .

[41]  R. Mccaffrey.  Slip vectors and stretching of the Sumatran fore arc , 1991 .

[42]  J. Dolan,et al.  Researchers investigate submarine faults north of Puerto Rico , 1997 .

[43]  V. Huérfano,et al.  Microseismic activity reveals two stress regimes in southwestern Puerto Rico , 2005 .

[44]  D. Wald,et al.  THE 1943-1953 NORTH-CENTRAL CARIBBEAN EARTHQUAKES : ACTIVE TECTONIC SETTING, SEISMIC HAZARDS, AND IMPLICATIONS FOR CARIBBEAN-NORTH AMERICA PLATE MOTIO NS , 1998 .

[45]  S. Stein,et al.  Subduction seismicity and tectonics in the lesser Antilles arc , 1982 .

[46]  J. Beavan,et al.  Rapid microplate rotations and backarc rifting at the transition between collision and subduction , 2005 .

[47]  T. Fitch.  Plate convergence, transcurrent faults, and internal deformation adjacent to Southeast Asia and the western Pacific , 1972 .

[48]  R. Mccaffrey.  On the role of the upper plate in great subduction zone earthquakes , 1993 .

[49]  Paul Mann,et al.  Actively evolving microplate formation by oblique collision and sideways motion along strike-slip faults: An example from the northeastern Caribbean plate margin , 1995 .

[50]  J. Nocquet,et al.  Deformation of the North American plate interior from a decade of continuous GPS measurements , 2006 .

[51]  E. Rabinowicz.  The Nature of the Static and Kinetic Coefficients of Friction , 1951 .

[52]  M. Beck.  On the mechanism of tectonic transport in zones of oblique subduction , 1983 .

[53]  L. Sykes,et al.  Subduction of aseismic ridges beneath the Caribbean Plate: Implications for the tectonics and seismic potential of the northeastern Caribbean , 1984 .

[54]  Y. Okada.  Internal deformation due to shear and tensile faults in a half-space , 1992, Bulletin of the Seismological Society of America.

[55]  P. Jansma,et al.  GPS results from Puerto Rico and the Virgin Islands: Constraints on tectonic setting and rates of active faulting , 2002 .

[56]  J. Dolan,et al.  Tectonic and Seismologic Setting of the 22 September 2003, Puerto Plata, Dominican Republic Earthquake: Implications for Earthquake Hazard in Northern Hispaniola , 2004 .

[57]  P. Bouysse,et al.  Relevé bathymétrique Seabeam et tectonique en décrochements au sud des Iles Vierges (Nord-Est Caraïbes) , 1987 .

[58]  Zuheir Altamimi,et al.  ITRF2000: A new release of the International Terrestrial Reference Frame for earth science applications , 2002 .

[59]  R. Russo,et al.  The 1946 Hispaniola earthquakes and the tectonics of the North America‐Caribbean plate boundary zone, northeastern Hispaniola , 1995 .

[60]  G. Proctor.  Ferns of Puerto Rico and the Virgin Islands , 1989 .

[61]  R. Laforge,et al.  A seismic source model for Puerto Rico, for use in probabilistic ground motion hazard analyses , 2005 .

[62]  C. Scholz.  The Mechanics of Earthquakes and Faulting , 1990 .

[63]  J. Oldow,et al.  Active displacement partitioning and arc-parallel extension of the Aleutian volcanic arc based on Global Positioning System geodesy and kinematic analysis , 2000 .

[64]  D. Wells,et al.  New empirical relationships among magnitude, rupture length, rupture width, rupture area, and surface displacement , 1994, Bulletin of the Seismological Society of America.

[65]  G. Burr,et al.  Tectonic geomorphology and paleoseismology of the Septentrional fault system, Dominican Republic , 1998 .

[66]  M. Cloos.  Thrust-type subduction-zone earthquakes and seamount asperities: A physical model for seismic rupture , 1992 .

[67]  G. Burr,et al.  Slip rate and earthquake recurrence along the central Septentrional fault, North American–Caribbean plate boundary, Dominican Republic , 2003 .

[68]  É. Calais,et al.  Strike-slip tectonics and seismicity along the northern Caribbean plate boundary from Cuba to Hispaniola , 1998 .

[69]  É. Calais,et al.  From transcurrent faulting to frontal subduction: A seismotectonic study of the Northern Caribbean P , 1992 .

[70]  C. Small,et al.  The effect of seamount subduction on seismic coupling , 1997 .

[71]  J. C. Savage.  A dislocation model of strain accumulation and release at a subduction zone , 1983 .

[72]  C. Demets.  A new estimate for present‐day Cocos‐Caribbean Plate motion: Implications for slip along the Central American Volcanic Arc , 2001 .

[73]  E. Rabinowicz.  The Intrinsic Variables affecting the Stick-Slip Process , 1958 .

[74]  Hiroo Kanamori,et al.  Seismicity and the subduction process , 1980 .

[75]  T. Dixon,et al.  Bookshelf faulting in Nicaragua , 2002 .

[76]  D. Masson,et al.  The neotectonic setting of Puerto Rico , 1991 .