Dip variations of the North American and North Caribbean Plates dominate the tectonic activity of Puerto Rico–Virgin Islands and adjacent areas

Abstract

The M 7.0 Haiti earthquake of 2010 in the Greater Antilles is a reminder that the northeastern Caribbean is at a high risk for seismic and tsunami hazards. The Greater Antilles consist of the Hispaniola microplate to the west and Puerto Rico–Virgin Islands to the east and are situated between two subduction zones with the Puerto Rico Trench to the north and the Muertos Trough to the south. Although there is no active volcanism on Puerto Rico, earthquake depths and previous seismic tomography results imply that the slabs of Caribbean and North American Plates exist at depth. However, how far the east Muertos Trough subduction of the North Caribbean Plate has extended has not been fully addressed. In addition, the Puerto Rico–Virgin Islands are bounded by extensional regimes to both the west (Mona Rift) and east (Anegada Passage). The cause of the extension is still under debate. In this paper, we use new 3D seismic tomography and gravity data to carry out an integrated study of the geometry of the subducting slabs of the North American and North Caribbean Plates in the Puerto Rico–Virgin Islands area. The results indicate that both slabs have an increase of dip westward, which is strongly controlled by the subduction rollback of the North American Plate. These variations affected the tectonic evolution of the Puerto Rico–Virgin Islands. Thus, the results of this research advance our understanding of the kinematic evolution of the Puerto Rico–Virgin Islands and associated natural hazards. Copyright © 2015 John Wiley & Sons, Ltd.

A New Method for the Collection of Marine Geomagnetic Information: Survey Application in the Colombian Caribbean

“…We have carried out an exhaustive search for data and geomagnetic surveys in the study area and, although no new works have been found, similar or related works have been carried out in the environment of the study area: magnetic mapping of the northern Caribbean region using marine magnetic data from GEODAS [55], works about gravity and magnetic field referring to hydrocarbon prospects at the Tobago Basin [56], geological description and interpretation in Providencia and Santa Catalina Islands [57], and many others related to tectonics and volcanism [58,59].…”