Jason Noel Ott

My name is Jason Ott, and I am a postdoctoral associate specializing in rock and mineral physics and structural petrology in the Rock Deformation Lab at Rice University in Houston, Texas. I am interested in the deformation mechanisms and metamorphic reactions that control the strength, and flow behavior (or rheology) of the lithosphere—the outermost shell of the Earth.

 

My research investigates the fundamental mechanics of shear zones—the narrow, high-strain regions acting as the primary agents of deformation within the Earth's crust. From the brittle faults of the San Andreas to deep-crustal flow in orogenic belts, I analyze how these zones accommodate tectonic plate movement at both plate boundaries and within continents. A central focus of my work is the brittle-ductile transition (BDT), a zone within the Earth where rocks shift from brittle faulting to ductile flowing behavior with increasing depth. The BDT typically marks the maximum depth at which large earthquakes can nucleate, so understanding how the rheology of the lithosphere evolves across this boundary gives essential insights into the scale and frequency of these geological hazards.

 

By pairing 'forensic' micro-scale analysis of naturally deformed rocks with high-pressure/high-temperature laboratory experiments, I explore how mineralogy and metamorphic reactions govern the strength and flow behavior of the Earth's crust. This integrated approach allows me to bridge the gap between microscopic (grain-scale) processes and large-scale dynamics of plate boundaries—helping to uncover how the faulting and flow behavior of rocks in the lithosphere ultimately drives the hazards, such as megathrust earthquakes, we experience at the surface.

​

During my PhD at the University of Washington, I studied the strength and deformation mechanisms in amphibole minerals in subduction zones under the mentorship of my advisor, Cailey Condit. Subduction zones are the complex regions where oceanic crust dives into the Earth to be recycled, and are a key element to understanding the plate tectonics of our home planet. Subduction zones host some of the most dangerous hazards on our planet, including megathrust earthquakes, tsunamis, and explosive volcanism-and are often in close proximity to population centers. Therefore, the work we do to better understand them is of importance beyond the scientific community.

 

I used electron microscopy to map the mineralogy and grain orientations in naturally deformed blueschist samples by electron backscatter diffraction (EBSD) and used the resulting maps to interpret the deformation history of these ancient subduction zone rocks. Energy-dispersive X-ray spectroscopy (EDS) and Electron Microprobe Analysis (EMPA) illustrated chemical variation within minerals, and together, these techniques give insight into the physical and chemical processes active in subduction zones. These observation-based studies of naturally deformed rocks were paired with in situ deformation experiments on glaucophane, the dominant amphibole mineral in many blueschists. Through these deformation experiments, conducted at MIT with collaborator Matěj Pěc, we developed a flow law relating stress to strain rate at laboratory conditions.  Bridging the gap between the experiments and natural rocks using their common microstructures, this combined field and laboratory approach improved our understanding of deformation along the subduction interface downdip of the seismogenic zone in particular and subduction zone dynamics as a whole.​