in this study, the development of structural elements and the relationship between these elements and dikes emplacements investigated by the field surveys and analysis of satellite images of the east dasht-e bayaz fault zone. in this area nnw-sse (t2) and nw-se trending dikes are which follow the fractures of the region. we measured geometric characters of dikes (such as thickness, attitude, di...

In this research seismicity parameters, repeat times and occurrence probability of large earthquakes are estimated for 35 seismic lineaments in Persian plateau and the surrounding area. 628 earthquakes of historical time and present century with MW>5.5 were used for further data analysis. A probabilistic model is used for forecasting future large earthquake occurrences in each chosen lineament....

the sangbast-shandiz fault zone, with a length of about 57 km, a width of moderately 2 km, and a nw-se direction, is located about 15 km in the west of mashhad city. that is one of the major faults in the binalud mountains. geomorphic evidences illustrate that the sangbast-shandiz fault zone has dextral strike- slip offsets with thrust activity. in this article, we investigated geomorphic featu...

Recent observations have shown that shear waves trapped within lowvelocity fault zones may be the most sensitive measure of fault-zone structure (Li e t al. , 1994a, 1994b). Finite-difference simulations demonstrate the effects of several types of complexi ty on observations of fault-zone trapped waves. Overlying sediments with a thickness more than one or two fault-zone widths and fault-zone s...

Active deformation in Alborz range is due to N-S convergence between Arabia and Eurasia. This paper provides geomorphic traces of regional deformation in NW Iran in order to characterize active faulting on major faults. Soltanieh and North Zanjan fault systems are involved in convergence boundary extent between South Caspian Basin and Central Iran. Soltanieh and North Zanjan faults are major re...

S U M M A R Y We present a statistical analysis of focal mechanism orientations for nine California fault zones with the goal of quantifying variations of fault zone heterogeneity at seismogenic depths. The focal mechanism data are generated from first motion polarities for earthquakes in the time period 1983–2004, magnitude range 0–5, and depth range 0–15 km. Only mechanisms with good quality ...

We deployed a dense linear array of 45 seismometers across and along the San Andreas fault near Parkfield a week after the M 6.0 Parkfield earthquake on 28 September 2004 to record fault-zone seismic waves generated by aftershocks and explosions. Seismic stations and explosions were co-sited with our previous experiment conducted in 2002. The data from repeated shots detonated in the fall of 20...

Fault zones are thought to consist of regions with reduced seismic velocity. When sources are located in or close to these low-velocity zones, guided seismic head and trapped waves are generated which may be indicative of the structure of fault zones at depth. Observations above several fault zones suggest that they are common features of near fault radiation, yet their interpretation may be hi...