**1. Introduction**

Tectonic and volcanic activities are intimately related to the interaction of different lithospheric plates and crustal blocks. In the study region of this paper, the tectonics and volcanic activity are directly related to the interaction of the Caribbean, South America, Nazca and Cocos plates, with the smaller North Andean, Maracaibo, Choco and Panama blocks wedged in between, as has been pointed out by various authors [1–13]. This highly complex tectono-dynamic configuration of intense intraplate deformation is manifested in a high density of faults, most of which are considered active or potentially active over northwestern South America and southeastern Central America. In addition, seismicity is spread over a broad area across the wide plate boundary in northwestern South America, Central America, and southwestern Caribbean. Also, several countries in this region present intense volcanic activity, such as Guatemala, Nicaragua, Costa Rica, Colombia and Ecuador, as well as on many of the islands of the Lesser Antilles.

There is no doubt that space geodesy has contributed significantly to the study of the kinematics of the Earth's crust, allowing to improve the understanding of the tectonics complexity at a global, regional and local level. The analysis and comprehension of the Earth's crust strain in several places of the world, with a variety of different characteristics and tectonic styles, has gradually been supported by the

results obtained from the geodetic networks, initially composed of field stations of data gathering under episodic campaigns type, and later by continuously operating reference stations (cGPS). Several authors have pointed out the extensive applications of space geodesy for scientific purposes, e.g. [14–16], among others. In the study area, despite the restrictions due to the limited coverage of the national GNSS/GPS networks, its impact is already being observed in studies of the Earth dynamics. The data from the stations have allowed the generation of high precision products such as geodetic time series, velocity fields and estimation of tectonic plate motion rates, seismic cycle analysis, estimation of the magnitude and spatial variability of the plate coupling, among other aspects. In addition to tectonic studies, its use has been extended to the volcano deformation monitoring in several countries (Colombia, Costa Rica, Ecuador, Nicaragua), subsidence studies; the use of data for ionosphere and troposphere studies as well as its inclusion, still in its initial state, in tsunami warning systems. Progress has also been made in the conception of multiparameter stations, based on the joint installation in the same site of diverse equipment such as geodetic, seismological, strong motion and meteorological instruments, among others. It is also important to note that there is a good data availability, although not from all stations due to particular restrictions, that allows its use for various scientific purposes. However, in some cases, through agreements or by formal request of data to national institutions, these can be obtained.
