Abstract:
Flow pulsations in two-phase and single-phase near-critical fluids are considered
as a possible source of ultra-low-frequency seismo-electromagnetic variations. The conditions
for generation and suppression of density wave instability in the crust are analyzed
and the surface electromagnetic effect due to streaming potential generation is estimated.
The upper limit of amplitude of magnetic field variations due to density wave instability is
about 0.1 nT for single-phase supercritical and 1 nT for two-phase flow oscillations in the
frequency range 104102 Hz for the temperature gradients and spatial scales possible
during strike slip events. The signal is characterized by a decaying amplitude with typical
relaxation time of about several quasi-periods. The possibility of generation of very lowfrequency
flow pulsations in two-phase fluids via individual bubble evolution and interaction
with external acoustic waves is discussed.
