This study will use space geodetic measurements (GPS and InSAR) to create a high spatial resolution, three-component map of crustal velocity in the central Andes during the past decade. The primary goal is to image possible along-strike variations in the inter-seismic deformation field. While the inter-seismic deformation field is interesting in its own right, and can be used to determine which parts of the subduction interface are locked (and might rupture in future earthquakes), the objective is to model this deformation so that it can be removed. This study seeks to isolate subtle low-amplitude deformation, including: 1) Bulk post-seismic relaxation following recent subduction zone earthquakes. 2) Aseismic motion on shallow crustal faults related to long-term mountain-building. 3) Magma movements in deep sub-crustal reservoirs and at low rates in shallow chambers. This study will use methods similar to those of previous studies (e.g., Peltzer et al., 2001, Wright et al., 2001), but will increase the amount of data and spatial coverage by 1-2 orders of magnitude, from the 10's of scenes of InSAR data used in previous studies to nearly 1000 scenes.
This study will help to better characterize hazards from earthquakes in two different environments -- subduction zones and within the continents. This project will also extend our previous surveys of hundreds of volcanoes for active deformation that could indicate magmatic movements and the need for further assessment of eruptive hazard. The software that will be developed in this study will become publicly available. This study will involve the training of graduate and undergraduate students, and will support an early career scientist.
