Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Dilatancy-induced fluid pressure drop during dynamic rupture: Direct
  experimental evidence and consequences for earthquake dynamics   Fluid pressure and flow in the crust is a key parameter controlling
earthquake physics. Since earthquake slip is linked to spatio-temporal
localisation of deformation, it is expected that the localised fluid pressure
around the fault plane could potentially impact the dynamic strength of the
slipping fault zone. Coseismic fluid pressure drops have been inferred from
field studies, notably in gold deposits which are thought to be formed by this
process, but reliable quantitative predictions are still lacking. Here,
experimental results are presented where local on- and off-fault fluid pressure
variations were measured in situ during dynamic rock fracture and frictional
slip under upper crustal stress conditions. During the main rupture, the
on-fault fluid pressure dropped rapidly to zero, indicating partial
vaporisation and/or degassing. Further deformation produced stick-slip events
systematically associated with near-instantaneous drops in fluid pressure,
providing direct experimental support of the concept of ``seismic suction
pump''. In situ fluid volume and wave speed measurements together with
microstructural investigations show that dilatancy is the process driving fluid
pressure drops during rupture and slip. Extrapolation of the laboratory results
indicate that dilatancy-induced fluid pressure drops might be a widespread
phenomenon in the crust, counteracting thermal pressurisation as a weakening
mechanisms in freshly fractured rock.

22
The categories of this paper are: chao-dyn
16
The categories of this paper are: stat
20
The categories of this paper are: acc-phys
33
The categories of this paper are: plasm-ph
11
The categories of this paper are: hep-lat
6
The categories of this paper are: astro-ph
26
The categories of this paper are: bayes-an
32
The categories of this paper are: atom-ph
31
The categories of this paper are: ao-sci
12
The categories of this paper are: nucl-th
2
The categories of this paper are: math
27
The categories of this paper are: comp-gas
9
The categories of this paper are: nlin
36
The categories of this paper are: cmp-lg
34
The categories of this paper are: chem-ph
19
The categories of this paper are: eess