Dr. Gerald Galgana


galgana@lpi.usra.edu

Research Interests

I am a geophysicist (geodesist) and I study crustal deformation processes on terrestrial planets.

On Venus: My primary interests are volcano-tectonic processes associated with large volcanic edifices (such as Tepev, Sif, and Maat Montes), and radially fractured centers (such as Pavlova and Mokos). I study the mechanical effects of volcano edifice loading on the evolution of magma chambers, magma ascent and the propagation of igneous intrusions at the surface and at depth. Related to this research are investigations of the formation of radial and ring dikes, which are theorized to originate from stresses caused by magma reservoir processes and flexural uplift of the Venusian lithosphere. I use numerical and analytic methods to model the interactions of magma chambers and lithospheric stresses.

On Earth: I study active deformation of the lithosphere, comparing both interplate and intraplate settings. I analyze microplate motion, seismicity patterns, elastic strain accumulation along faults, intra- and inter-block deformation, and strain partitioning processes along active, convergent plate boundary zones. To accomplish this, I use numerical and analytic models constrained by plate velocities obtained from high-precision space geodetic (GPS) observations, earthquake focal mechanisms and other geophysical data. Similarly, within intraplate settings such as the Central United States, I study minute strain rates associated with active seismicity and deformation of the thick, relatively stable continental crust.

I also study volcano-tectonic processes on Earth using GPS to observe time-varying deformation of volcanic edifices. I use inversion techniques to locate and determine the geometries of magmatic sources and then use finite element analysis to study complex processes associated with active deformation of volcanic edifices.

 

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Last updated
May 17, 2011