De:: Giuseppe Giunta 072003 <giuntape@...>
Asunto: Re: [carib] New Publication - A GPS and modeling study of deformation in northern Central America
A: carib@yahoogroups.com
Fecha: lunes 20 de julio de 2009, 1:37

 

I have some papers on the tectonic geometry of the southern margin of the
Caribbean Plate but they don't deal with the seismotectonic pattern.
Frank Audemard is author of several papers on the seismotectonic of that
areas, and you can contact him for more informations.
I suppose that Frank, who is also connected at the carib site, is reding this
email.
All the best.
Giuseppe

On Sun, 19 Jul 2009 15:55:54 -0430, Pascual Marquez wrote
> Yes, it is an interesting paper, I ask if there is any research like
> this going on the southern border of the Caribbean Plate,
> particularly along the Oca Fault.
>
> On Sat, Jul 18, 2009 at 11:49 AM, Giuseppe Giunta 072003
> <giuntape@unipa. it>wrote:
>
> >
> >
> > Hi Rob,
> > this is a wonderful paper, which confirms several seismotectonic ideas and
> > opens many problems on the seismic hazard evaluation.
> > We are working on the tectonics of the area, and I would like to keep in
> > contact with you for discussion and improvement of our work.
> > I should go in Central America in the next November; I will inform you
> > about
> > my agenda.
> > All the best.
> > Giuseppe
> >
> > Prof. Giuseppe Giunta
> > Dipartimento di Geologia, Università di Palermo (Italia)
> > Via Archirafi 20-22, 90100 Palermo (Italia)
> > tel. +39 0916230337 - cell. +39 3297979921
> > giuntape@unipa. it <giuntape%40unipa. it>
> >
> > On Fri, 17 Jul 2009 09:53:09 -0700, robert rogers wrote
> > > Rodriguez M, DeMets C, Rogers R, Tenorio C, Hernandez D (2009) A GPS
> > > and modeling study of deformation in northern Central America.
> > > Geophysical Journal International
> > >
> > > published online: 13 Jul 2009
> > >
> > > http://www3. interscience. wiley.com/ journal/12251098 8/abstract
> > >
> > > We use GPS measurements at 37 stations in Honduras and El Salvador
> > > to describe active deformation of the western end of the Caribbean
> > > Plate between the Motagua fault and Central American volcanic arc.
> > > All GPS sites located in eastern Honduras move with the Caribbean
> > > Plate, in accord with geologic evidence for an absence of
> > > neotectonic deformation in this region. Relative to the Caribbean
> > > Plate, the other stations in the study area move west to
> > > [UTF-8?][UTF- 8?]west–northwest at rates that increase gradually
from 3.3 ± 0.6
> > mm
> > > [UTF-8?][UTF- 8?]yr−1 in central Honduras to 4.1 ± 0.6 mm
[UTF-8?][UTF- 8?]yr−1 in
> > western
> > > Honduras to as high as [UTF-8?][UTF- 8?]11–12 mm
[UTF-8?][UTF- 8?]yr−1 in southern
> > Guatemala. The
> > > site motions are consistent with slow westward extension that has
> > > been inferred by previous authors from the north-striking grabens
> > > and earthquake focal mechanisms in this region. We examine the
> > > factors that influence the regional deformation by comparing the new
> > > GPS velocity field to velocity fields predicted by finite element
> > > models (FEMs) that incorporate the regional plate boundary faults
> > > and known plate motions. Our modeling suggests that the obliquely
> > > convergent [UTF-8?][UTF- 8?](∼20°) direction of
[UTF-8?][UTF- 8?]Caribbean–North
> > American Plate
> > > motion relative to the Motagua fault west of 90°W impedes the ENE-
> > > directed motion of the Caribbean Plate in southern Guatemala, giving
> > > rise to extension in southern Guatemala and western Honduras. The
> > > FEM predictions agree even better with the measured velocities if
> > > the plate motion west of the Central American volcanic arc is forced
> > > to occur over a broad zone rather than along a single through going
> > > plate boundary fault. Our analysis confirms key predictions of a
> > > previous numerical model for deformation in this region, and also
> > > indicates that the curvature of the Motagua fault causes significant
> > > along-strike changes in the orientations of the principal strain-
> > > rate axes in the fault borderlands, in accord with earthquake focal
> > > mechanisms and conclusions reached in a recent synthesis of the
> > > structural and morphologic data from Honduras. Poor fits of our
> > > preferred models to the velocities of GPS sites near the Gulf of
> > > Fonseca may be an artifact of the still-short GPS time-series in
> > > this region or the simplifying assumptions of our FEMs
> > >
> > > ------------ --------- --------- ------
> > >
> > > Dr. Robert Rogers
> > >
> > > Assistant Professor
> > >
> > > Geology Program, Department of Physics and Geology
> > >
> > > California State University, Stanislaus
> > >
> > > One University Circle, Turlock, CA 95382
> > >
> > > Tel. 209 664-6691
> > >
> > > email: <mailto:rrogers@geology. csustan.edu<rrogers%40geology. csustan.edu> >
> > rrogers@geology. csustan.edu <rrogers%40geology. csustan.edu>
> > >
> > > home: <http://geology. csustan.edu/ rrogers/>
> > http://geology. csustan.edu/ rrogers/
> > >
> > > Honduras Geology:
> > > <http://geology. csustan.edu/ rrogers/honduras /index.htm>
> > http://geology. csustan.edu/ rrogers/honduras /index.htm
> >
> >
> >

Prof. Giuseppe Giunta
Dipartimento di Geologia, Università di Palermo (Italia)
Via Archirafi 20-22, 90100 Palermo (Italia)
tel. +39 0916230337 - cell. +39 3297979921
giuntape@unipa. it