**4. Data processing and velocity field**

The Geological Survey of Colombia received a grant to host a Regional Data Center headquartered in Bogotá that serves the entire circum–Caribbean community and functions as a mirror for COCONet data and metadata [54]. From the existing stations in the study area and displayed in **Figure 3**, the International Geodesy Lab of GeoRED currently processes 214 stations located on the Caribbean, South America, Nazca and Cocos tectonic plates across many country borders (**Figure 4**).

All GPS data obtained in the own format of each receiver are converted to RINEX format using the TEQC (Translating. Editing. Quality Check) tool developed by UNAVCO [55]. GPS data processing is carried out using the scientific software GIPSY-X/RTGx v 1.3 developed by JPL-CALTECH-NASA [56], and made *GNSS Networks for Geodynamics in the Caribbean, Northwestern South America, and Central… DOI: http://dx.doi.org/10.5772/intechopen.97215*

**Figure 4.** *cGPS stations processed at GeoRED-GSC.*

the French National Research Agency. Initial efforts by FUNVISIS since 2003 have focused on the installation of 2 local campaign networks (western and eastern Venezuela) of more than 70 benchmarks. These data is complementary for tectonic

**COUNTRY N° of**

Aruba 1 Guadeloupe 1 Nicaragua 4 Belize 1 Guatemala 3 Panama 12 British Virgin Is. 1 Haiti 1 Puerto Rico 4

Colombia 141 Jamaica 3 St. Lucia 3 Costa Rica 55 Las Bahamas 1 Trinidad & Tobago 1 Cuba 2 Martinique 1 Venezuela 6 Ecuador 37 Mexico 2 Virgin Islands 1

Anguilla 1 El Salvador 4 Montserrat

Cayman Is. 4 Honduras 4 Dominican

**Stations**

2 Grenada 1 Netherlands

**COUNTRY N° of**

(Antilles)

Antilles

Republic

**Stations**

1

1

8

**Table 1** indicates the number of stations installed in each country that are part of

In terms of instrumentation, **Figure 3** depicts that cGPS station distribution is rather homogenous throughout the Caribbean region and adjacent areas, except for 3 countries (Colombia, Costa Rica and Ecuador). Such homogeneity is a result from

The Geological Survey of Colombia received a grant to host a Regional Data Center headquartered in Bogotá that serves the entire circum–Caribbean community and functions as a mirror for COCONet data and metadata [54]. From the existing stations in the study area and displayed in **Figure 3**, the International Geodesy Lab of GeoRED currently processes 214 stations located on the Caribbean, South America, Nazca and Cocos tectonic plates across many country borders

All GPS data obtained in the own format of each receiver are converted to RINEX format using the TEQC (Translating. Editing. Quality Check) tool developed by UNAVCO [55]. GPS data processing is carried out using the scientific software GIPSY-X/RTGx v 1.3 developed by JPL-CALTECH-NASA [56], and made

the study area, which are represented in **Figure 3**. It is possible that there are additional stations in some countries, but we have considered that these stations will improve, in a short-term, the understanding of the geodynamics of the study

*Number of cGPS stations discriminated by country in the study region and depicted in Figure 3.*

the COCONet project implementation, trying to reduce large gaps of data availabilty. Conversely, the concentration of stations in the 3 abovementioned countries responds to national policies, as already mentioned (Nicoya experiment in Costa Rica, post-Pedernales 2016 earthquake instrumentation in Ecuador and

studies.

**Table 1.**

region.

(**Figure 4**).

**150**

GeoRED project in Colombia).

**COUNTRY N° of**

Antigua & Barbuda

**Stations**

*Geodetic Sciences - Theory, Applications and Recent Developments*

**4. Data processing and velocity field**

available to GeoRED under a cooperation agreement. Final orbits are used in the processing, which include satellite orbits of the GNSS constellations, satellite clock and Earth orientation parameters that are provided in the appropriate format for Gipsy-X by JPL-NASA as contribution to the International GNSS Service (IGS). For the estimation of the tropospheric delay of the GNSS signals, the numerical model known as the Vienna Mapping Function (VMF1) is used, which is an update of the previous model known as VMF [57]. The ocean loading corrections are obtained from the Onsala Space Observatory, and are applied to eliminate the land and ocean tides. The amplitudes and phases of the main oceanic tidal loading terms are estimated by applying the FES2014b model [58]. The processing includes ionospheric models generated regularly by the IGS.

GIPSY-X/RTGx v 1.3 software uses the Precise Point Positioning (PPP) data processing strategy which is based on obtaining precise reference satellite orbit and clock products using the IGS GNSS global network.

Site coordinates for each day are computed in the non-fiducial frame and transformed to the ITRF2014 frame using a 7-parameter Helmert transformation [59]. The ECEF coordinates have been transformed into topocentric coordinates, which allow daily changes in the coordinates to be expressed in terms of local displacements in the North, East and Up (NEU) components with respect to a position in an initial epoch.

GPS time series have been generated using the HECTOR software v 1.7.2 [60] developed by SEGAL (Space & Earth Geodetic Analysis Laboratory), a center formed by the cooperation between the University of the Interior of Beira (UBI) and the Geophysical Institute Infante D. Luiz (IDL) from Portugal. HECTOR is a specialized software for the study of geodetic time series, which allows estimating the time series trend with temporal noise correlations. It is a dynamic software that only accepts stationary noise with constant noise properties, which allows fast matrix operations, benefiting the reduction in processing time.

For the estimation of geodetic velocities, GeoRED has adopted the recommendation of [61], who consider that the period of time of data required to estimate a trend in geodetic stations should be at least 2.5 years, in order to avoid that the estimated motion rate can be affected by various types of noise, including seasonal noise. Thus, the period of observations used in the processing extends to the time range from 2.5 to 20 years. January 1, 2010 is used as the reference epoch for all velocities estimation rather than the midpoint of each individual time series. For the time series estimation, it was used a combined model of power law plus white noise, and power spectrum predicted and observed plots were generated, to verify that the appropriate noise model has been used.

We present a new horizontal velocity field using data from 105 cGPS stations located in the study region. **Figure 5** shows the velocities with respect to ITRF2014. **Figure 6** shows the velocities with respect to the South American plate (SOAM), **Table 2**, following the procedure described by [40], who determined the velocity field using only 60 cGPS stations. These new velocity vectors allow observing the strain partitioning at different scales at the four PBZs of the Caribbean plate.

The ISCO station, Costa Rica, located on the Cocos plate, subducts beneath Central America, and shows the highest velocity in the study area, 86 mm/yr. wrt SOAM; similar value was obtained by [40] in ITRF2008. The importance of continuous geodetic instrumentation for the seismic cycle monitoring in this zone is indicated by [62] analyzing the occurrence of the Mw 7.6 September 5, 2012, Costa Rica earthquake, recorded in the network installed in the Nicoya Peninsula [51].

> The ISCO station, installed in 2011, is the only place that allows estimating the motion of the Cocos plate using GNSS geodetic instruments [63]; these authors estimated the Cocos-Caribbean convergence by comparing the baseline between ISCO and the SANO station, located on the island of San Andrés on the Caribbean plate, obtaining a value of 78 1 mm/yr expressed in ITRF2008. We have made the same comparison, but expressed in ITRF2014, obtaining a value of 76.8 0.5 mm/ yr. This result is in agreement with the MORVEL estimate of [43] mentioned by

*GPS horizontal velocity field wrt to SOAM, ITRF2014. Table 2 provides the actual values of all GPS site*

*GNSS Networks for Geodynamics in the Caribbean, Northwestern South America, and Central…*

*DOI: http://dx.doi.org/10.5772/intechopen.97215*

Six stations, located on islands in the western sector of the Caribbean plate, show an east-southeast general direction of motion, in a range of 96° to 101° of azimuth, and velocities with respect to SOAM of 18.7 0.3 mm/yr (SAN0), 17.1 0.3 mm/yr (CN35), 16.7 0.5 mm/yr (CAYS), 15.9 0.4 mm/yr (CN11), 15.3 0.3 mm/yr (CN10), and 12.9 0.3 mm/yr (CN12). On the other hand, three stations located on the eastern side of the Caribbean plate on islands of the Lesser Antilles, show velocity values with respect to SOAM about 17.1 0.7 mm/yr (CN01), 16.6 0.5 mm/yr (AMBF) and 18.9 0.4 mm/yr (LMMF), in a general east-

MALO (Malpelo Island) and GLPS (Galapagos Island) stations confirm the rapid motion of the Nazca plate wrt to SOAM. The estimated velocity values in ITRF2014 are not so different from those estimated by [40] in ITRF2008. The ITRF2014 velocities are 53.2 0.5 mm/yr with an azimuth of 87.8° for MALO, and

The GPS stations located on the Colombian coast of the Pacific Ocean show similar values to those obtained by [40], increasing the velocity to the south. However, the ESMR station, located in Ecuadorean coast shows variation in the

northeast direction, with azimuth values in the range of 76° to 78°.

54.9 0.2 mm/yr and azimuth 87.8° for GLPS.

[63] of 76.4 2.5 mm/yr.

**Figure 6.**

**153**

*velocities depicted here.*

**Figure 5.** *GPS horizontal velocity field wrt to ITRF 2014.*

*GNSS Networks for Geodynamics in the Caribbean, Northwestern South America, and Central… DOI: http://dx.doi.org/10.5772/intechopen.97215*

**Figure 6.**

the time series trend with temporal noise correlations. It is a dynamic software that only accepts stationary noise with constant noise properties, which allows fast

For the estimation of geodetic velocities, GeoRED has adopted the recommendation of [61], who consider that the period of time of data required to estimate a trend in geodetic stations should be at least 2.5 years, in order to avoid that the estimated motion rate can be affected by various types of noise, including seasonal noise. Thus, the period of observations used in the processing extends to the time range from 2.5 to 20 years. January 1, 2010 is used as the reference epoch for all velocities estimation rather than the midpoint of each individual time series. For the time series estimation, it was used a combined model of power law plus white noise, and power spectrum predicted and observed plots were generated, to verify that the

We present a new horizontal velocity field using data from 105 cGPS stations located in the study region. **Figure 5** shows the velocities with respect to ITRF2014. **Figure 6** shows the velocities with respect to the South American plate (SOAM), **Table 2**, following the procedure described by [40], who determined the velocity field using only 60 cGPS stations. These new velocity vectors allow observing the strain partitioning at different scales at the four PBZs of the Caribbean plate. The ISCO station, Costa Rica, located on the Cocos plate, subducts beneath Central America, and shows the highest velocity in the study area, 86 mm/yr. wrt SOAM; similar value was obtained by [40] in ITRF2008. The importance of continuous geodetic instrumentation for the seismic cycle monitoring in this zone is indicated by [62] analyzing the occurrence of the Mw 7.6 September 5, 2012, Costa Rica earthquake, recorded in the network installed in the Nicoya Peninsula [51].

matrix operations, benefiting the reduction in processing time.

*Geodetic Sciences - Theory, Applications and Recent Developments*

appropriate noise model has been used.

**Figure 5.**

**152**

*GPS horizontal velocity field wrt to ITRF 2014.*

*GPS horizontal velocity field wrt to SOAM, ITRF2014. Table 2 provides the actual values of all GPS site velocities depicted here.*

The ISCO station, installed in 2011, is the only place that allows estimating the motion of the Cocos plate using GNSS geodetic instruments [63]; these authors estimated the Cocos-Caribbean convergence by comparing the baseline between ISCO and the SANO station, located on the island of San Andrés on the Caribbean plate, obtaining a value of 78 1 mm/yr expressed in ITRF2008. We have made the same comparison, but expressed in ITRF2014, obtaining a value of 76.8 0.5 mm/ yr. This result is in agreement with the MORVEL estimate of [43] mentioned by [63] of 76.4 2.5 mm/yr.

Six stations, located on islands in the western sector of the Caribbean plate, show an east-southeast general direction of motion, in a range of 96° to 101° of azimuth, and velocities with respect to SOAM of 18.7 0.3 mm/yr (SAN0), 17.1 0.3 mm/yr (CN35), 16.7 0.5 mm/yr (CAYS), 15.9 0.4 mm/yr (CN11), 15.3 0.3 mm/yr (CN10), and 12.9 0.3 mm/yr (CN12). On the other hand, three stations located on the eastern side of the Caribbean plate on islands of the Lesser Antilles, show velocity values with respect to SOAM about 17.1 0.7 mm/yr (CN01), 16.6 0.5 mm/yr (AMBF) and 18.9 0.4 mm/yr (LMMF), in a general eastnortheast direction, with azimuth values in the range of 76° to 78°.

MALO (Malpelo Island) and GLPS (Galapagos Island) stations confirm the rapid motion of the Nazca plate wrt to SOAM. The estimated velocity values in ITRF2014 are not so different from those estimated by [40] in ITRF2008. The ITRF2014 velocities are 53.2 0.5 mm/yr with an azimuth of 87.8° for MALO, and 54.9 0.2 mm/yr and azimuth 87.8° for GLPS.

The GPS stations located on the Colombian coast of the Pacific Ocean show similar values to those obtained by [40], increasing the velocity to the south. However, the ESMR station, located in Ecuadorean coast shows variation in the


**ID**

**155**

CCPA

CCSQ

CIOH

CN01

CN05

CN06

CN10

CN11

CN12

CN14

CN19

CN20

CN28

CN29

CN35

CN36

CN38

CN39

CN40

CN41

COEC

CORO

75.288

 9.328

 17.5

 1.5

 0.3

 0.2

 VORI

77.672

 0.863

 6.8

 2.2

 0.3

 0.3

77.787

 0.716

 7.1

 0.9

 0.6

 0.2

 VNEI

75.255

 3.062

 4.7

 3.4

 0.3

 0.3

68.042

 8.943

 0.9

 0.6

 0.4

 0.3

 VMER

77.153

 1.785

 7.4

 3.0

 0.2

 0.2

68.958

 12.180

 18.1

 1.9

 0.2

 0.2

 VEDE

75.765

 4.460

 7.6

 3.9

 0.4

 0.3

70.524

 10.206

 13.3

 1.7

 1.8

 1.1

 VDPR

73.248

 10.436

 14.0

 4.9

 0.2

 0.2

71.988

 12.222

 17.1

 3.4

 0.5

 0.2

 VBUV

73.859

 5.533

 8.0

 4.8

 0.4

 0.2

75.821

 8.820

 23.6

 0.9

 1.4

 1.7

 UWAS

72.391

 6.451

 5.4

 2.3

 0.3

 0.2

81.363

 13.376

 16.9

2.4

 0.6

 0.3

 URR0

76.210

 8.012

 18.8

 1.7

 0.3

 0.3

83.375

 14.049

 16.9

2.4

 0.5

 0.4

 TUCO

78.748

 1.815

 18.4

 1.9

 0.4

 0.2

79.034

 8.625

 23.9

 3.5

 0.4

 0.3

 TONE

76.139

 6.324

 9.6

 5.2

 0.2

 0.2

82.256

 9.352

 22.5

 0.8

 0.6

 0.5

 TICU

69.939

4.187

 0.2

 0.0

 0.4

 0.2

70.049

 12.612

 18.4

 2.2

 0.2

 0.2

 TEAT

73.539

 5.422

 5.9

 3.4

 0.5

 0.3

*GNSS Networks for Geodynamics in the Caribbean, Northwestern South America, and Central…*

73.678

 20.975

76.749

 18.004

 12.7 1.2

4.2

 0.3

 0.3

 SSIA

89.117

 13.697

 12.7

1.4

 0.4

 0.4

2.5

 0.5

 0.3

 SNLR

78.847

 1.293

 14.0

 0.2

 0.5

 0.2

77.784

 17.021

 15.8

1.9

 0.3

 0.2

 SGCG

73.064

 6.992

 10.5

 4.0

 0.3

 0.7

75.971

 17.415

 15.2

1.5

 0.3

 0.2

 SEL1

75.529

 6.191

 9.3

 4.6

 0.3

 0.2

70.656

 18.790

 11.0

3.4

 0.4

 0.3

 SCUB

75.762

 20.012

 1.0

5.4

 0.2

 0.2

68.359

 18.564

 12.1

0.2

 0.2

 0.2

 SAN0

81.716

 12.580

 18.5

2.5

 0.2

 0.2

*DOI: http://dx.doi.org/10.5772/intechopen.97215*

61.765

 17.048

 16.7

 3.8

 0.5

 0.4

 SALF

78.155

0.233

 2.7

 1.9

 1.3

 0.2

75.534

 10.391

 17.8

 0.2

 0.8

 0.2

 ROA0

86.527

 16.318

 17.6

 0.0

 0.7

 0.2

76.474

 3.063

 8.2

 1.9

 0.8

 0.3

 RIOP

78.651

1.651

 3.2

2.0

 0.5

 0.5

76.085

 4.325

 8.5

 4.8

 1.0

 0.5

 RDSD

**LON**

 **LAT**

 **Vel E**

 **Vel N**

 **Sig E**

 **Sig N**

 **ID**

 **LON** 69.911

 18.461

 13.4

2.5

 0.4

 0.3

 **LAT**

 **Vel E**

 **Vel N**

 **Sig E**

 **Sig N**


*GNSS Networks for Geodynamics in the Caribbean, Northwestern South America, and Central… DOI: http://dx.doi.org/10.5772/intechopen.97215*

**ID**

**154**

ABCH

ABMF

ACHO

ACP1

ACP6

AJCM

ALPA

ANCH

AOPR

AUCA

BA3E

BAAP

BAEZ

BAME

BAPA

BASO

BIEC

BOBG

BOGT

BUGT

CAYS

CCAN

76.300

 3.360

 8.3

 3.6

 0.4

 0.4

 QUIL

77.291

 1.394

 7.3

 2.9

 0.5

 0.3

79.846

 15.795

 16.4

3.3

 0.5

 0.2

 QSEC

85.357

 9.840

 17.0

 13.9

 1.4

 1.3

76.996

 3.826

 10.6

 4.1

 0.3

 0.2

 PUIN

67.903

 3.851

74.081

 4.640

 4.6

 4.8

 0.3

 0.2

 POVA

76.615

 2.449

 9.2 0.1

 0.1

 0.3

 0.2

 2.9

 0.4

 0.2

73.358

 8.312

 12.3

 4.4

 0.4

 0.2

 PLTR

75.332

 5.044

 8.4

 4.8

 0.4

 0.4

78.502

1.447

1.2

 0.8

 0.4

 0.5

 PASI

76.499

 0.513

 0.2

0.3

 0.5

 0.2

77.393

 6.203

 12.0

 5.1

 0.8

 0.4

 PAL2

73.184

 7.131

 9.0

 3.7

 0.3

 0.3

74.658

 5.466

 8.0

 4.5

 0.2

 0.2

 OVSC

77.257

 1.210

 3.3

 2.1

 0.3

 0.2

74.565

 4.236

 6.1

 3.7

 0.3

 0.3

 OCEL

71.616

 4.271

 0.4

 0.6

 0.4

 0.1

77.887

0.459

 2.3

0.1

 0.8

 0.3

 MORA

73.683

 8.959

 13.1

 4.0

 0.3

 0.3

73.554

 4.072

 0.4

0.1

 0.3

 0.1

 MOPR

67.931

 18.077

 14.3

 0.9

 0.4

 0.2

75.234

 0.742

76.883

0.641

 0.5 1.2

0.5

 1.2

 0.2

 MOME

80.047

 0.492

 6.6

 3.8

 2.6

 0.9

0.9

 0.4

 0.2

 MITU

70.232

 1.261

 0.5

 0.7

 0.2

 0.1

66.754

 18.347

 14.4

 2.4

 0.3

 0.2

 MIPR

66.527

 17.886

 15.0

 2.6

 0.2

 0.1

76.870

 3.535

 9.3

 3.2

 0.3

 0.3

 MECE

73.712

 7.107

 9.7

 4.6

 0.3

 0.2

72.918

 11.528

 15.9

 4.0

 0.5

 0.5

 MANA

86.249

 12.149

 13.2

 1.0

 0.4

 0.3

*Geodetic Sciences - Theory, Applications and Recent Developments*

74.885

 5.210

 8.7

 4.7

 0.3

 0.2

 MALO

79.408

 9.238

 22.1

 2.6

 0.2

 0.2

 LUMB

77.328

81.606

 4.003

 53.0

 4.5

 0.5

 0.3

 0.137

 1.1

1.0

 0.7

 0.3

79.950

 9.371

 22.0

 2.0

 0.2

 0.2

 LMMF

60.996

 14.595

 18.5

 3.9

 0.4

 0.2

80.173

 7.415

 36.7

 2.4

 0.9

 0.4

 ISCO

87.056

 5.544

 55.4

 65.1

 0.7

 0.4

61.528

 16.262

 16.1

 3.9

 0.3

 0.3

 INVE

74.232

 11.188

 15.7

 4.9

 0.4

 0.1

73.722

 4.638

 4.8

 2.7

 0.3

 0.2

 INTO

**LON**

 **LAT**

 **Vel E**

 **Vel N**

 **Sig E**

 **Sig N**

 **ID**

 **LON** 76.043

 4.642

 8.1

 4.2

 0.4

 0.2

 **LAT**

 **Vel E**

 **Vel N**

 **Sig E**

 **Sig N**


**Table 2.** *GPS site velocities (mm/yr) relative to SOAM in ITRF2014.*

northern component of velocity, which can be attributed to the effect of the 2016 Pedernales earthquake [64, 65]. It is important to note that the velocity field of [40] is estimated based on data until March 2016, prior to the aforementioned earthquake. The new velocity field contains the offsets associated to the coseismic displacements for the generation of the respective time series and velocity estimation. At regional scale, wrt to SOAM, we can clearly see how NAB (in the sense of [3]) is detached from SOAM, and is moving at around from few mm/yr to a ten of mm/ yr in the ENE-NE direction. In a general manner, slip rates within NAB tend to decrease from west to east, from the pacific border towards inland, and from south to north, implying coupling at the over-ridding plate-slab interface (e.g. [27]). Meanwhile, the Caribbean plate seems to exhibit a more similar (more homogenous) slip rate across the plate, trending E-ESE. The herein obtained values across the Caribbean plate tend to confirm the ≈20 mm/yr of eastward motion of this thickened oceanic plate already known per years now. However, it is very clear now

*GNSS Networks for Geodynamics in the Caribbean, Northwestern South America, and Central…*

that the Panamá block probably is not part of the Caribbean plate, because

block against SA (and directly to NAB; e.g. [13, 28–30, 39, 40]).

**5. Conclusions**

observation.

at each station used in the solution.

*DOI: http://dx.doi.org/10.5772/intechopen.97215*

east-southeast to east-northeast.

**Acknowledgements**

**157**

instrumentation for the study of the seismic cycle.

exhibiting a higher slip rate to the E-ENE than the rest of the Caribbean plate (e.g. [12, 39, 40]). It appears that such higher slip rate is transferred to NAB located to the east, confirming the indentation-extrusion mechanism responsible for the tectonic escape of NAB, as a consequence of collision and later suturing of the Chocó

A new horizontal geodetic velocity field wrt SOAM is presented, expressed in ITRF2014. With respect to the previous estimate, the spatial coverage of the study area has been increased, as well as the number of stations and the observation time

The precision of the ISCO motion estimation, located on the Cocos plate, has been improved with respect to previous estimation, using data from 7.6 years of

Although there are no substantial differences in the station velocities processed in this study, located on islands both west and east of the Caribbean plate, except for that shown by one station, it can be concluded that the Caribbean plate probably does not behave uniformly as a unit, as one might conclude from the difference between the directions, about 21°, changing in the general direction from

The study region shows examples of the importance of GNSS geodetic

To the Geological Survey of Colombia for supporting the Space Geodesy Research Group which has allowed the implementation and development of the

0043000220000 from the National Planning Department, and second, 2018-2021 funded under the institutional code 1000810 as part of the Research, Monitoring and Evaluation of Geological Hazards in the national territory. TO UNAVCO for its permanent support and for facilitating our participation in the COCONet project as well as the installation of stations in several countries, including in our countries of Colombia and Venezuela; also for the grant that permitted the implementation of the Regional Data Center in Bogotá, Colombia. To the Geophysical Institute of the

GeoRED project, first between 2007 and 2016, funded by the grant

*GNSS Networks for Geodynamics in the Caribbean, Northwestern South America, and Central… DOI: http://dx.doi.org/10.5772/intechopen.97215*

northern component of velocity, which can be attributed to the effect of the 2016 Pedernales earthquake [64, 65]. It is important to note that the velocity field of [40] is estimated based on data until March 2016, prior to the aforementioned earthquake. The new velocity field contains the offsets associated to the coseismic displacements for the generation of the respective time series and velocity estimation.

At regional scale, wrt to SOAM, we can clearly see how NAB (in the sense of [3]) is detached from SOAM, and is moving at around from few mm/yr to a ten of mm/ yr in the ENE-NE direction. In a general manner, slip rates within NAB tend to decrease from west to east, from the pacific border towards inland, and from south to north, implying coupling at the over-ridding plate-slab interface (e.g. [27]). Meanwhile, the Caribbean plate seems to exhibit a more similar (more homogenous) slip rate across the plate, trending E-ESE. The herein obtained values across the Caribbean plate tend to confirm the ≈20 mm/yr of eastward motion of this thickened oceanic plate already known per years now. However, it is very clear now that the Panamá block probably is not part of the Caribbean plate, because exhibiting a higher slip rate to the E-ENE than the rest of the Caribbean plate (e.g. [12, 39, 40]). It appears that such higher slip rate is transferred to NAB located to the east, confirming the indentation-extrusion mechanism responsible for the tectonic escape of NAB, as a consequence of collision and later suturing of the Chocó block against SA (and directly to NAB; e.g. [13, 28–30, 39, 40]).
