The Mechanics of Slow Slip on Faults and Fractures
CONDITIONS OF ORIGINATION AND POSSIBILITY OF TRANSFORMATIONS.
CONSEQUENCES AND IMPORTANCE FOR SEISMIC HAZARD REDUCTION.
The problem of the proposed project is detecting laws of origination, development and transformation of transient modes of rock discontinuity deformation. Such regimes include events of seismogenic slip along faults, fractures and other interfaces at velocities 1-3 orders of magnitude less than those of "conventional" earthquakes, as well as episodes of aseismic creep.
The urgency of the problem is defined by the fact that laws of spatial and temporal variations of deformation regimes at different segments of faults in the Earth's crust are poorly understood. Detecting regularities of formation of different deformation regimes may turn out to be a breakthrough in solving numerous fundamental and applied problems.
The scientific novelty of the project is that for the first time at different hierarchical levels the conditions, parameters and characteristics will be detected that control the prevailing regime of slip on faults and fractures, as well as possible regularities of transition from one regime to another.
Laboratory, numerical and field investigations are planned in the project.
Laboratory experiments will be conducted at two set-ups in IDG RAS and JIHT RAS. The common task of laboratory experiments will be investigating the effects of different characteristics of interblock contacts and their stress-strain conditions on the slip regime. Special attention will be paid to the effect of external disturbances (vibrations of various intensities and durations, gradual fluidization of the contact, variations of pore pressure). The conditions of transformation of slip modes will be investigated.
Numerical experiments will be aimed at investigating regularities of deformation of interblock contacts with complex rheology, which is difficult to implement in laboratory tests.
Two types of 'in situ' experiments are planned in the project – simultaneous hydrogeological and seismological observations at the geophysical station of IDG RAS "Mikhnevo", and deformation and seismic measurements at one of the faults of the Baikal Rift Zone.
The results of laboratory, field and numerical experiments are planned to be summarized in the form of the model of the phenomenon.
