P-to-S converted teleseismic waves recorded by temporary broadband networks across Tibet show a north-dipping interface that begins 50 kilometers north of the Zangbo suture at the depth of the Moho (80 kilometers) and extends to a depth of 200 kilometers beneath the Bangong suture. Under northern Tibet a segmented south-dipping structure was imaged. These observations suggest a different form of detachment of the Indian and Asian lithospheric mantles caused by differences in their composition and buoyancy.

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[1] The S receiver function technique was applied to the recordings from 36 broad-band stations in the Tien Shan. The results reveal a pronounced difference in the properties of the lithosphereasthenosphere of the Tien Shan and those of the neighboring platforms. Beneath the Tien Shan, an upper-mantle lid with an S velocity of about 4.5 km/s is underlain at a depth of about 90 km by a low-velocity zone, where the S velocity drops to 4.1 -4.2 km/ s. Trends of P and S travel time residuals are consistent with the presence of melt or other liquids in this zone. There is no evidence of any similar layer beneath the platforms. The crust is 55 -65 km thick beneath most of the Tien Shan and 45 km below the platforms, although it thins to about 45 km near the Naryn basin in the central Tien Shan.

S U M M A R YThe Archean Dharwar craton in south India is known for long time to be different from most other cratons. Specifically, at station Hyderabad (HYB) the Ps converted phases from the 410-and 660-km mantle discontinuities arrive up to 2 s later than in other cratons of comparable age, which implies lower upper mantle velocities. To resolve the unique lithosphere-asthenosphere system of the Dharwar craton, we inverted jointly P and S receiver functions and teleseismic P and S traveltime residuals at 10 seismograph stations. This method operates in the same depth range as long-period surface waves but differs by much higher lateral and radial resolution. We observe striking differences in crustal structures between the eastern and western Dharwar craton (EDC and WDC, respectively): crustal thickness is of around 31 km, with predominantly felsic velocities, in the EDC and of around 55 km, with predominantly mafic velocities, in the WDC. In the mantle we observe significant variations in the P velocity with depth, practically without accompanying variations in the S velocity. In the mantle S velocity there are azimuthdependent indications of the Hales discontinuity at a depth of ∼100 km. The most conspicuous feature of our models is the lack of the high velocity mantle keel with the S velocity of ∼4.7 km s −1 , typical of other Archean cratons. The S velocity in our models is close to 4.5 km s −1 from the Moho to a depth of ∼250 km. There are indications of a similar upper mantle structure in the northeast of the Indian craton and of a partial recovery of the normal shield structure in the northwest. A division between the high S-velocity western Tibet and low S-velocity eastern Tibet may be related to a similar division between the northeastern and northwestern Indian craton.

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[1] Fault zones are the locations where motion of tectonic plates, often associated with earthquakes, is accommodated. Despite a rapid increase in the understanding of faults in the last decades, our knowledge of their geometry, petrophysical properties, and controlling processes remains incomplete. The central questions addressed here in our study of the Dead Sea Transform (DST) in the Middle East are as follows: (1) What are the structure and kinematics of a large fault zone? (2) What controls its structure and kinematics? (3) How does the DST compare to other plate boundary fault zones? The DST has accommodated a total of 105 km of leftlateral transform motion between the African and Arabian plates since early Miocene ($20 Ma). The DST segment between the Dead Sea and the Red Sea, called the Arava/ Araba Fault (AF), is studied here using a multidisciplinary and multiscale approach from the mm to the plate tectonic scale. We observe that under the DST a narrow, subvertical zone cuts through crust and lithosphere. First, from west to east the crustal thickness increases smoothly from 26 to 39 km, and a subhorizontal lower crustal reflector is detected east of the AF. Second, several faults exist in the upper crust in a 40 km wide zone centered on the AF, but none have kilometer-size zones of decreased seismic velocities or zones of high electrical conductivities in the upper crust expected for large damage zones. Third, the AF is the main branch of the DST system, even though it has accommodated only a part (up to 60 km) of the overall 105 km of sinistral plate motion. Fourth, the AF acts as a barrier to fluids to a depth of 4 km, and the lithology changes abruptly across it. Fifth, in the top few hundred meters of the AF a locally transpressional regime is observed in a 100-300 m wide zone of deformed and displaced material, bordered by subparallel faults forming a positive flower structure. Other segments of the AF have a transtensional character with small pull-aparts along them. The damage zones of the individual faults are only 5 -20 m wide at this depth range.

[1] We evaluate seismic attenuation in the inner core from the spectral ratio between the seismic phase PKP(DF ) and either PKP(AB) or PKP(BC ) at the epicentral distances from 150°to 170°. The global data set is divided into two groups according to the position of the turning point of PKP(DF ) either in the eastern (from 50°E to 120°W) or the western hemisphere. In the eastern hemisphere the parameter t 8 shows strong dependence on the epicentral distance and no dependence on the angle between the Earth's spin axis and PKP(DF ) ray at the turning point. In the western hemisphere t 8 is weakly dependent on the distance, and varies between approximately 0.7 s and 0.1 s for the angles between 0°and 90°, respectively. Our results allow us to reconcile seemingly incompatible results of many previous studies. The anisotropy of attenuation is correlated with the anisotropy of P velocity.