The experiment leading to the 'Array of Arrays' involves a single, dense, small-aperture seismic array we installed in the same area that we later reoccupied for the multiple arrays experiment (see above). I developed a technique to detect and locate tremor [Ghosh et al., 2009]. Using this technique, I demonstarte that tremor behavior during an ETS in Cascadia is more complex than previously thought, and changes dramatically over the observation time scale. I find that tremor in Cascadia migrates in different direction with different velocities indicating a complex interaction between geologic structure, high fluid pressure, and stress transfer [Ghosh et al., 2009, Ghosh et al., 2010a, Ghosh et al., 2010b]. Thses migration patterns give new insight to the evolution of slip during an ETS, and help better understand the underlying physics.