MAPPING DEFORMATION WITH SPACE GEODESY
Space geodesy has broad implications in the definition of global geodetic reference frames, navigation and security. However, here, we are interested to develop techniques for the analysis of geodetic data focused to obtain estimates of surface ground deformation (improving precision and/or time and spatial resolutions). Such detailed knowledge of the ground deformation field have benefits in the modelling of natural hazard problems (active volcanism and tectonics). A keystone of our developments is to obtain reliable uncertainties of the deformation parameters.
On-going projects in this line of research:
Phase-Corr: Robust phase cross-correlation method for ground displacements.
MTIANPAC: Multitemporal InSAR Analysis Package (w/ error estimation).
UnwrapFixGUI: An easy-to-use GUI for unwrapping errors corrections.
Using a combination of structural geology, geophysical and geodetic data, we study how volcanoes deform. For example, how a repeated sets of microgravity surveys soon after a period of unrest could serve for the monitoring of fluid migrations after a dike intrusion (Gottsmann et al., 2006). Also a hot topic in volcano geodesy is the evaluation of structural stability of volcanic edifices and the study of frictional and kinematic properties of basal (decollements) and intra-volcanic fault systems (González et al., 2010). In general, the development of ground deformation monitoring systems (Prieto et al., 2009).
Past areas: New Zealand
Current areas: Canary Islands, Italy, East African Rift, and Hawaii.
Prospecting areas: elsewhere.
EARTHQUAKE AND TECTONIC DEFORMATION
Continental deformation can be determined using seismotectonics and geodesy. We study the instantaneous (present-day) deformation kinematics using geodetic data from GPS networks and/or satellite radar interferometric surveys. This snapshots can be combined with long-standing views from geomorphology and structural geology. In particular, we have analyzed some recent earthquakes using radar interferometry (González et al., 2009). More complex models of co- and postseismic deformation of high-strain deformation areas are necessary to understand the role of such areas in a low rate convergence diffuse plate boundaries (González et al., FRINGE 2010). In the future, we are interest to develop kinematics models to explain the current deformation partition at such low rate convergence diffuse plate boundaries.
Past areas: Iran, D.R. Congo and North Anatolian Fault system (Turkey).
Current areas: Betic-Rif arc, Eastern Canada and Western US (California-Nevada).
Prospecting areas: Cascadia.
GEOTHERMAL AND AQUIFER RESERVOIRS
A new perspective to the groundwater resource studies is the application of radar interferometry. In that context, recently we discovered the largest subsidence place in Europe (> 10 cm/year), and proof that aquifer response is driven by temporal non-linear pore-pressure diffusion processes (González and Fernández, GEOLOGY 2011). In the future, we are also interested to develop anelastic (poro-, visco-, plastic,…) models to explain deformation at shallow reservoirs in volcanic areas. The ultimate goal is to understand high-pressure and high-temperature fluid flow at geothermal reservoirs, this research line can potentially contribute to the monitoring and safety exploitation of CO2 sequestration sites.
Areas: Saskatoon (Canada), Spain in particular Canary Islands.