CANAPE
A GPS Study of Caribbean Plate Kinematics and Distributed Deformation
Between the Caribbean and North American Plates
Principal Investigators:
Dennis DeMets (Dept. of Geology & Geophysics, University of Wisconsin-Madison)
Tim Dixon (Rosenstiel School of Marine & Atmospheric Sciences, University of Miami)
Pamela E. Jansma (Dept. of Geosciences, Univ. of Arkansas, Fayetteville, Arkansas)
Paul Mann (UTIG)
Glen Mattioli (National Science Foundation, Arlington, Virginia)
Eric Calais (Dept. of Earth & Atmospheric Sciences, Purdue University, West
Lafayette, Indiana)
Funded by: National Science Foundation -
Geophysics, Award #9806464
Publications
Project Summary
The work proposed herein is part of a long-term collaborative effort to measure the
present-day motion of the Caribbean plate and to determine the manner in which rigid plate
motion is accommodated along the Caribbean-North America plate boundary in the
northeastern Caribbean. In 1986, a  geodetic network spanning the Caribbean-North
America plate boundary was established and occupied with GPS receivers, thereby setting
the stage for future determinations of site displacements that could resolve major
unanswered questions concerning crustal deformation and plate motions in the northeastern
Caribbean. In 1994, the investigators submitting this proposal re-occupied (and expanded)
the 1986 network for the first time, and in 1995, we re-occupied a critical subset of
those sites.
We have now completely analyzed observations from 1986, 1994, and 1995 and have solved
for velocities at all sites that were occupied more than once. These results are detailed
in a manuscript that we submitted to JGR in mid-March. Briefly, we found the following:
(1) Velocities of all sites on the rigid Caribbean plate are more than twice as fast as
predicted by the NUVEL-1A model, giving the largest known velocity discrepancy for any
plate pair (Caribbean-North America) relative to the predictions of the widely used
NUVEL-1A model. This indicates there is significant mismodeling of circum-Caribbean
kinematics in the NUVEL-1A model and thus demonstrates a need for a concerted effort to
measure and model the Caribbean plate's present motion using geodetic techniques; (2)
Velocities of sites that transect the plate boundary in Hispaniola define an elastic
strain field that is poorly fit by models that assume that all slip occurs along a single
strike-slip fault, thereby indicating that slip is partitioned. However, our data are too
few and poorly constrained to do anything but impose a broad range of slip rates on the
major faults; further observations will significantly improve our resolution of these slip
rates.
The results to date are clearly exciting and merit further investigation. The main
objectives of the proposed study are as follows: 1) To construct a Caribbean plate
kinematic model using GPS- derived velocities from sites that span the Caribbean plate and
to use the same velocities to establish an upper bound on any intra-Caribbean deformation,
(2) To determine the slip rate and level of elastic strain accumulation along the
Septentrional fault in  northern Hispaniola, which has not experienced a major
earthquake in more than 700 years despite geologic evidence for 15-20 mm yr-1
of slip over the past several thousand years, and (3) To determine how Caribbean-North
America motion is partitioned by the faults that separate the two plates in the vicinity
of Hispaniola and Puerto Rico, and ultimately, to extract information about the dynamics
of this plate boundary by modeling elastic strain and extracting block rotations from the
velocity field.
At present, we have squeezed the most that we can from our present sparse set of
velocities. As such, no further progress will occur until we are able to re-occupy
existing sites and modestly expand and densify the network. By early 1998, which is the
soonest that we could feasibly re-occupy sites in the network, nearly four years will have
passed since the last occupation of the majority of our network (4/94). Sufficient time
will thus have passed for measurable (ranging from 10-100 millimeters) displacements
within our network. We request funding for the following: (A) A modest expansion of our
network to collect and/or reduce data from sites that span the geographic limits of the
rigid or near-rigid Caribbean plate. These include pre-existing sites at San Andres (1),
Aves (1), eastern Costa Rica (1), and St. Croix (1), new sites in Jamaica (2) and northern
Honduras (1), and a no-cost continuous GPS NOAA site in eastern Jamaica, (B) Densification
of the network in Hispaniola (~15 new sites) to permit better measurement and modeling of
the fault-partitioned strain field on this complexly deforrming island, and (3) Two
occupations of all of the sites (3540) in the network. The importance and relevance of
each of these goals to our and other GPS projects in the Caribbean region is outlined in
more detail below.
Publications on Caribbean wide GPS network including results from
northeastern Caribbean CANAPE (Caribbean-North America Plate Experiment)
network:
Focus on the GPS data from sites within the stable interior of the Caribbean plate:
DeMets, C., Jansma, P., Mattioli, G., Dixon, T., Farina, F., Bilham, R.,
Calais, E., and Mann, P., 2000, GPS geodetic constraints on Caribbean-North
American plate motion, Geophysical Research Letters, v. 27, p. 437-440.
Focus on GPS data from the entire NSF-funded CANAPE network:
Dixon, T., Farina, F., DeMets, C., Jansma, P., Mann, P., and Calais, E.,
1998, Relative motion between the Caribbean and North American plates and
related boundary zone deformation based on a decade of GPS observations,
Journal of Geophysical Research, v. 103, p. 15,157-15,182.
Focus on subset of CANAPE GPS data from the Puerto Rico-Virgin Islands area:
Jansma, P., Lopez, A., Mattioli, G., DeMets, C., Dixon, T., Mann, P., and
Calais, E., 2000, Neotectonics of Puerto Rico and the Virgin Islands, northeastern Caribbean, from GPS geodesy, Tectonics, v. 19, p.
1021-1037.
Focus on the subset of CANAPE GPS data from the Hispaniola-Bahama platform
oblique collision area:
Calais, E., Mazabraund, Y, Mercier de Lepinay, B., Mann, P., Mattioli, G.,
and Jansma, P., 2002, Strain partitioning and fault slip rates in the
northeastern Caribbean from GPS measurements: Geophysicsal Research Letters,
v. 29, no. 18, 1856, doi:10:1029/2002GL015397, 2002.
Pollitz, F., and Dixon, T., 1998, GPS measurements across the northern
Caribbean plate boundary zone; Impact of posteismic relaxation following
historic earthquakes, Geophysical Research Letters, v. 25, p. 2233-2236.
Mann, P., Prentice, C., Burr, G., Pena, L., and Taylor, F. W., 1998,
Tectonic geomorphology and paleoseismology of the Septentrional fault zone,
Dominican Republic, in J. F. Dolan and P. Mann, editors, Active Strike-slip
and Collisional Tectonics of the Northern Caribbean Plate Boundary Zone,
Geological Society of America Special Paper 324, p. 63-123.
Mann, P., Calais, E.,Ruegg, J-C., DeMets, C., Jansma, P., and Mattioli, G.,
2002, Oblique collision in the northeastern Caribbean from GPS measurements
and geological observations: Tectonics, v. 21, no. 6, 1057,
doi:10.1029?2001TC001304, 2002.
Focus on the subset of CANAPE GPS data from the Caribbean-Northern
South America area:
Weber, J.C., Dixon, T.H., DeMets, C., Ambeh, W.B., Jansma, P., Mattioli,
G., Saleh, J., Sella, G., Bilham, R., and Perez, O., 2001, GPS estimate of
relative motion between the Caribbean and South American plates, and
geologic implications for Trinidad and Venezuela, Geology, 29(1): 75-78.
Focus on northern South America using results from the GPS network operated
by Perez, Bilham, et al.:
Perez, O.J., Bilham, R., Bendick, R., Velandia, J.R., Hernandez, N.,
Moncayo, C., Hoyer, M., and Kozuch, M., 2001, Velocity field across the
southern Caribbean plate boundary and estimates of Caribbean/South-American
plate motion using GPS geodesy 1994-2000; Geophysical Research Letters, v.
28, p. 2987-2990.
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