8 research outputs found
Deep structure of the Alborz Mountains by joint inversion of P receiver functions and dispersion curves
The Alborz Mountains represent a tectonically and seismically active convergent boundary in the Arabia \u2013 Eurasia collision zone, in western Asia. The orogenic belt has undergone a long-lasted tectono-magmatic history since the Cretaceous. The relationship between shallow and deep structures in this complex tectonic domain is not straightforward. We present a 2D velocity model constructed by the assemblage of 1D shear wave velocity (Vs) models from 26 seismic stations, mainly distributed along the southern flank of the Alborz Mountains. The shear wave velocity structure has been estimated beneath each station using joint inversion of P-waves receiver functions and Rayleigh wave dispersion curves. A substantiation of the Vs inversion results sits on the modeling of Bouguer gravity anomaly data. Our velocity and density models show low velocity/density anomalies in uppermost mantle of western and central Alborz at a depth range of 3c50\u2013100 km. In deeper parts of the up- permost mantle (depth range of 100\u2013150 km), a high velocity/density anomaly is located beneath most of the Mountain range. The spatial pattern of these low and high velocity/density structures in the upper mantle is interpreted as the result of post collisional delamination of lower part of the western and central Alborz lithosphere
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New Constraints for the OnâShore Makran Subduction Zone Crustal Structure
Funder: Institute for Advanced Studies in Basic Sciences; Id: http://dx.doi.org/10.13039/501100007513Abstract: The Makran Subduction Zone is the primary seismic/tsunami hazard of the northwestern Indian Ocean, but little is known of its onâshore seismic structure. We derived a shear wave velocity model extending to > 100 km depth beneath a âŒ400 kmâlong seismic profile oriented parallel to the convergence vector of the Arabian Sea Plate. Receiver function/surface wave analysis shows that the average structure in the coastal region comprises a âŒ22â28 kmâthick low wavespeed sedimentary cover and a 6â8 kmâthick gradient zone overlying > 100 kmâthick high wavespeed upper mantle. The oceanâbasement interface dips gently northward, remaining a positive impedance contrast to âŒ50 km depth at âŒ250 km north of the coast where it disappears as the basaltic/gabbroic oceanic crust has probably transformed to eclogite. Further north, a weak arrival at âŒ5 s in the receiver functions appears, grading northward into the Moho arrival of the continental Iranian Plateau. This disruption in the seismic signature of the Moho occurs in the forearc region where the dip of the subducting oceanic plate steepens. The southern Iranian Plateau's continental crust has an average V s of 3.55 ± 0.05 km sâ1, an almost flat Moho 40â45 km deep, and a subâMoho mantle V s of 3.75 ± 0.05 km sâ1 in the 50â80 km depth range. Weak Moho conversions probably result from âŒ20% serpentinization of peridotite in the mantle wedge. Receiver functions indicate a flat continental Moho â no crustal root beneath the high topography region of the volcanic belt, which therefore must be compensated by low upper mantle densities. The high V p /V s ratio observed for the mantle wedge suggests âŒ1%â2% partial melt
Plasma treatment in textile industry
Plasma technology applied to textiles is a dry, environmentally- and worker-friendly method
to achieve surface alteration without modifying the bulk properties of different materials.
In particular, atmospheric non-thermal plasmas are suited because most textile materials
are heat sensitive polymers and applicable in a
continuous processes. In the last years plasma
technology has become a very active, high growth
research field, assuming a great importance among
all available material surface modifications in
textile industry. The main objective of this review
is to provide a critical update on the current state of
art relating plasma technologies applied to textile
industryFernando Oliveira (SFRH/BD/65254/2009) acknowledges Fundacao para a Cioncia e Tecnologia, Portugal, for its doctoral grant financial support. Andrea Zille (C2011-UMINHO-2C2T-01) acknowledges funding from Programa Compromisso para a Cioncia 2008, Portugal
Coseismic Deformation Field of the Mw 7.3 12 November 2017 Sarpol-e Zahab (Iran) Earthquake: A Decoupling Horizon in the Northern Zagros Mountains Inferred from InSAR Observations
The study of crustal deformation fields caused by earthquakes is important for a better understanding of seismic hazard and growth of geological structures in tectonically active areas. In this study, we present, using interferometric measurements constructed from Sentinel-1 Terrain Observation with Progressive Scan (TOPS) data and ALOS-2 ScanSAR, coseismic deformation and source model of the Mw 7.3, 12 November 2017 earthquake that hit northwest of the Zagros Mountains in the region between IranâIraq border. This was one of the strongest seismic events to hit this region in the past century, and it resulted in an uplift area of about 3500 km2 between the High Zagros Fault (HZF) and Mountain Front Fault (MFF) with a maximum amount of 70 cm south of Miringe fault. A subsidence over an area of 1200 km2 with a maximum amount of 35 cm occurred near Vanisar village at the hanging wall of the HZF. Bayesian inversion of interferometric synthetic aperture radar (InSAR) observations suggests a source model at a depth between 14 and 20 km that is consistent with the existence of a decoupling horizon southwest edge of the northern portion of the Zagros Mountains near the MFF. Moreover, we present evidence for a number of coseismically induced rockslides and landslides, the majority of them which occurred along or close to pre-existing faults, causing decorrelation in differential interferograms. Exploiting the offset-tracking technique, we estimated surface motion by up to 34 and 10 m in horizontal and vertical directions, respectively, due to lateral spreading on a big coseismic-induced landslide near Mela-Kabod. Field observations also revealed several zones of en echelon fractures and crack zones developed along a pre-existing fault passing through Qasr-e Shirin City, which exhibited secondary surface slip by up to 14 cm along its strike