Fractal singularity analysis (FSA) is used to study a 22-year record of deep seismic tremor (33--60 km depth) for regions below Kilauea Volcano on the assumption that magma transport and fracture can be treated as a system of coupled nonlinear oscillators. Tremor episodes range from 1 to 100 min (cumulative duration=1.6¿104 min; yearly average=727 min yr-1; mean gradient=24.2 min yr-1 km-1). Partitioning of probabilities, pi, in the phase space of normalized durations, xi, are expressed in terms of a function f(&agr;), where &agr; is a variable exponent of a length scale l. Plots of f(&agr;) vs. &agr; are called multifractal singularity spectra. The spectrum for deep tremor durations is bounded by &agr; values of about 0.4 and 1.9 at f=0; fmax≂1.0 for &agr;≂1. Results for tremor are similar to those found for systems transitional between complete mode locking and chaos. ¿ American Geophysical Union