  We numerically simulate a thermalization process in an energy landscape with
hierarchically organized metastable states. The initial configuration is chosen
to have a large energy excess, relative to the thermal equilibrium value at the
running temperature. We show that the initial energy surplus is dissipated in a
series of intermittent bursts, or quakes, whose rate decreases as the inverse
of the age of the system. In addition, one observes energy fluctuations with a
zero centered Gaussian distribution. These pertain to the pseudo equilibrium
dynamics within a single metastable state, and do not contribute to the energy
dissipation. The derivative of the thermal energy with respect to the logarithm
of time is asymptotically constant, and comprises a temperature independent
part, and a part with an Arrhenius temperature dependence. The findings closely
mirror recent numerical simulation results obtained for microscopic glassy
models. For these models, record-sized energy fluctuations have been claimed to
trigger intermittent events during low temperature thermalization. In the
present model record-sized fluctuations are by construction needed to trigger
changes from one metastable state to another. This property thus suffices to
explain the statistical property of intermittent energy flow in complex
metastable systems.
