ALBERT

Description: The reactions of As 2 O 3 , SbCl 3 , and (BiO) 2 CO 3 with oleum (65 % SO 3 ) yielded single crystals of As(S 2 O 7 )(HS 2 O 7 ) [monoclinic, P 2 1 / c , Z = 4, a = 16.549(1), b = 6.6743(5), c = 9.9498(6) Å, β = 102.672(8)°, V = 1072.672(8) Å 3 ], Sb 2 (SO 4 ) 2 (S 2 O 7 ) [monoclinic, P 2 1 / n , Z = 4, a = 9.1586(2), b = 6.9981(2), c = 17.7956(4) Å, β = 100.9690(8)°, V = 1119.73(5) Å 3 ], and Bi 2 (S 2 O 7 ) 3 [triclinic, P , Z = 2, a = 6.5734(1), b = 10.1954(2), c = 11.5121(2) Å, α = 90.996(1)°, β = 96.976(1)°, γ = 94.870(1)°, V = 762.75(2) Å 3 ]. As(S 2 O 7 )(HS 2 O 7 ) shows the arsenic atoms in a trigonal pyramidal coordination of the oxygen atoms of one chelating S 2 O 7 2– and one monodentate HS 2 O 7 – group. The distinct As(S 2 O 7 )(HS 2 O 7 ) molecules are connected with each other by hydrogen bonds to form layers. Sb 2 (SO 4 ) 2 (S 2 O 7 ) shows the Sb 3+ cations in a seesaw-type coordination of oxygen atoms from both anions. In Bi 2 (S 2 O 7 ) 3 the Bi 3+ cations are in a square prismatic oxygen coordination of disulfate units. The antimony and the bismuth compounds exhibit complex three-dimensionally linked structures. The syntheses and the crystal structures, as well as the thermal decomposition of Sb 2 (SO 4 ) 2 (S 2 O 7 ) are presented.

Description: Silver acetate AgOAc reacts with dry liquid ammonia under the formation of colorless needle-shaped crystals of diammine silver(I) acetate [Ag(NH 3 ) 2 ]OAc ( 1 ). The compound crystallizes in the monoclinic space group P 2 1 / c with a = 8.0205(2), b = 12.4161(3), c = 6.0938(2) Å, β = 107.741(4)°, and V = 577.98(3) Å 3 at 123 K with Z = 4. The crystal structure shows the presence of almost linear [Ag(NH 3 ) 2 ] + cations, which are arranged in a corrugated chain of equidistant silver atoms. The Ag–Ag distance is 3.1089(11) Å, which falls in the range of “argentophilic” interactions. After warming to room temperature and removal of the solvent, compound 1 was found unchanged as evidenced by powder X-ray diffraction, thermogravimetric and mass-spectrometric analysis, as well as IR and Raman spectroscopy.

Description: A series of chalcogenidoantimonates, namely [Zn(NH 3 ) 6 ](Sb III 4 S 7 ) ( 1 ), [Zn(NH 3 ) 6 ]{Zn(NH 3 ) 3 Sb V S 4 } 2 · NH 3 ( 2 ), [Mn(NH 3 ) 6 ](Sb III Se 2 ) 2 ( 3 ) and [Zn(NH 3 ) 4 ]{Zn(NH 3 )Sb III Se 3 } 2 · 3NH 3 ( 4 ) are synthesized by solvothermal technique in liquid ammonia at 50 °C from elemental zinc or manganese, antimony and sulfur or selenium. 1 (space group P ) and 2 ( P ) crystallize centrosymmetrically, whereas 3 ( Pna 2 1 ) and 4 ( P 2 1 ) represent polar structures. All compounds contain discrete cationic [Zn(NH 3 ) 4 ] 2+ , [Zn(NH 3 ) 6 ] 2+ , and [Mn(NH 3 ) 6 ] 2+ ammine complexes. In the anionic structure parts, corner-connected trigonal-pyramidal SbS 3 and SbSe 3 are the characteristic building units. 1 and 4 contain 2D polymeric anions, in the latter case with Zn 2+ cations incorporated in a selenidoantimonate(III) network. The polymeric anion in the structure of 3 is a helical chain. 2 is a molecular compound and contains dinuclear anions [S 3 Sb–S–Zn(NH 3 ) 3 ] 2– with Sb V . Raman measurements show the Sb–Ch valence vibrations in the expected region between 250–370 cm –1 for 1 and at 212 cm –1 for 4 . According to the reflectance spectrum 4 is a semiconductor with an optical band gap of 2.05(5) eV.

Description: [1]  We investigated the evolution of seismicity and deformation in the unstable eastern flank of Etna volcano over a thirty-year period (from 1980 to 2012). A significant temporal correlation has been revealed between periods of flank acceleration and intensified seismic activity by comparing seismicity along the northern border (Pernicana fault system) of the sliding flank and the deformation of the eastern flank. Two marked phases have been observed in 1984-1986 and in the years following 2002. These two phases are separated by an intermediate phase from 1987 to 2001, in which the flank sliding slowed down and the seismicity dropped drastically. This common temporal evolution in the deformation rate and seismic release supports the hypothesis that the seismicity in the northern border can be viewed as a marker of the response to accommodate the stress exerted by the traction of the eastern flank sliding. This interplay has also been corroborated by Finite Element Method (FEM) numerical computations that highlight a good correlation between the seismicity pattern and areas of positive stress changes induced by the sliding surface. The two intense phases of flank acceleration are representative of two main different sources: volcano flank instability stretching the eastern sector in the first 1984-1986 phase and magmatic intrusions pushing the eastern flank seaward since the 2002-03 eruption. Establishing the relationship between flank acceleration and seismic activation, therefore, contributes to understanding Etna's mechanical behavior, and provides insights into the processes regulating the unstable flank response.

Description: [1]  Numerous studies in the Central Pyrenees have provided evidence for a rapid phase of exhumation of this mountain belt during the Late Eocene (37–30 Ma). Simultaneously, the closure of the Ebro foreland basin allowed the accumulation of sediments at the southern Piedmont, which partially covered the fold-and-thrust belt from Late Eocene ( e . g . when it was still actively deforming) to Miocene times. We aim here at understanding the consequences of such syn-tectonic sedimentation on the Southern Pyrenean fold-and-thrust belt by using a 2-D numerical model that reproduces the development of a thin-skinned wedge subject to different modes of sedimentation and erosion. The results show contrasting fold-and-thrust belt behavior when applying aggrading or prograding sedimentation, which we link to the critical state of the wedge. When the sediments are sourced from the hinterland (progradation), the thrusting propagates toward the foreland; whereas when the sediments aggrade from the basin, the thrusting sequence migrates backward. This latter mode shows patterns of deformation that compare favorably to the Pyrenean thrusting sequence observed during Eocene-Miocene times.

Description: [1]  In southern California, fault slip rate estimates along the San Andreas fault (SAF) and Garlock fault from geodetically-constrained kinematic models are systematically at the low end or lower than geologic slip rate estimates. The sum of geodetic model slip rates across the Eastern California Shear Zone is higher than the geologic sum. However, the ranges of reported model and geologic slip rate estimates in the literature are sufficiently large that it remains unclear whether these apparent discrepancies are real, or attributable to epistemic uncertainties in the two types of estimates. We further examine uncertainties in geodetically-derived slip rate estimates on major faults in southern California by conducting a suite of inversions with four kinematic models. Long-term-rigid elastic block models constrained by the geologic slip rates cannot fit the present-day GPS-derived velocity field. Deforming (permanent off-fault strain) elastic block models and viscoelastic earthquake cycle block models constrained by geologic slip rates can fit the present-day GPS-derived velocity field with 28-33% of the total geodetic moment rate occurring as distributed deformation off of the major faults. Models incorporating viscoelastic mantle flow predict systematically higher slip rates than purely elastic models on many of the the major southern California faults with ranges of (elastic/viscoelastic) 29-34/30-37 mm/yr for the Carrizo SAF segment, 20-24/20-32 mm/yr for the Mojave SAF segment, 14-17/18-22 mm/yr for the Coachella SAF segment, 13-19/14-22 mm/yr for the San Jacinto fault, and 5-11/5-11 mm/yr for the western Garlock fault.

Description: . Sr 2 CoOsO 6 , a new osmium based ordered semiconductor double perovskite was prepared by solid state synthesis from the respective binary oxides. Room temperature PXRD analysis shows the compound to be tetragonal [ I 4/ m ; a = 5.5503(1) Å and c = 7.9320(1) Å], whereas low temperature synchrotron data refinement has revealed a second monoclinic polymorph [ I 2/ m ; a = 5.4969(2) Å, b = 5.4979(2) Å, c = 8.0090(1) Å and γ = 90.527(1)°] with a fully ordered rocksalt arrangement of cobalt and osmium atoms over the perovskite B -sites. Heat capacity and magnetic measurements indicate that Sr 2 CoOsO 6 shows antiferromagnetic ordering below T N = 108 K followed by a second magnetic transition at T 2 = 65 K. It was shown that the change from the tetragonal to the monoclinic phase occurs at T N .

Description: . The ternary germanides RE Rh 6 Ge 4 ( RE = Y, La, Pr, Nd, Sm–Lu) were obtained by arc-melting of the elements and subsequent annealing. Single crystals were grown from bismuth fluxes. The samples were studied by X-ray diffraction on powders. The structures of five members were refined from single crystal diffraction data: LiCo 6 P 4 type, P m 2, a = 715.8(1), c = 387.33(8) pm, wR = 0.0238, 332 F 2 values for LaRh 6 Ge 4 , a = 715.0(1), c = 384.96(7) pm, wR = 0.0211, 329 F 2 values for PrRh 6 Ge 4 , a = 714.28(9), c = 382.57(6) pm, wR = 0.0136, 327 F 2 values for SmRh 6 Ge 4 , a = 714.2(1), c = 381.6(1), wR = 0.0270, 327 F 2 values for GdRh 6 Ge 4 , and a = 714.2(2), c = 379.0(1) pm, wR = 0.0273, 324 F 2 values for HoRh 6 Ge 4 with 19 variables per refinement. The RE Rh 6 Ge 4 structures have two crystallographically independent germanium sites in trigonal prismatic coordination, manifesting the close structural relationship with metal-rich phosphides. Together, the rhodium and germanium atoms build up three-dimensional [Rh 6 Ge 4 ] networks, which leave large channels for the rare earth atoms. Each rare earth atom has coordination number 20 with 12 Rh, 6 Ge, and 2 RE neighbors. Temperature dependent magnetic susceptibility measurements indicate Pauli paramagnetic behavior for YRh 6 Ge 4 , LaRh 6 Ge 4 , and LuRh 6 Ge 4 . The compounds RE Rh 6 Ge 4 ( RE = Gd–Yb) are Curie-Weiss paramagnets. Antiferromagnetic ordering was observed at 8.4(5) K (GdRh 6 Ge 4 ), 13.6(5) K (TbRh 6 Ge 4 ), 5.1(5) K (DyRh 6 Ge 4 ), and 8.9(5) K (YbRh 6 Ge 4 ). DyRh 6 Ge 4 and YbRh 6 Ge 4 show metamagnetic transitions at 2.5(5) and 45(2) kOe, respectively.

Description: Reaction of manganese(II) thiocyanate with 2-chloropyrazine leads always to the formation of a compound of composition Mn(NCS) 2 (2-chloropyrazine) 4 ( 1 - Mn/Cl ) that consists of discrete complexes, in which the manganese cation is coordinated by two terminal thiocyanato anions and four 2-chloropyrazine ligands. In contrast, with 2-methylpyrazine only an aqua complex of composition Mn(NCS) 2 (2-methylpyrazine) 2 (H 2 O) 2 ( 1 - Mn/CH 3 ) is obtained that also consists of discrete octahedrally coordinated complexes. Moreover, a few single crystals of Mn(NCS) 2 (2-chloropyrazine) 4 · Mn(NCS) 2 (2-chloropyrazine) 2 (H 2 O) 2 · 2-chloropyrazine trisolvate ( 2 - Mn/Cl ) and Mn(NCS) 2 (2-methylpyrazine) 2 (H 2 O) 2 · Mn(NCS) 2 (H 2 O) 4 ( 2 - Mn/CH 3 ) were accidently obtained but no larger amounts are available. On heating, 1 - Mn/Cl and 1 - Mn/CH 3 transforms into new compounds of composition Mn(NCS) 2 (L) 2 (L = 2-chloropyrazine) ( 4 - Mn/Cl ) and 2-methylpyrazine ( 3 - Mn/CH 3 ). Surprisingly on further heating 1 - Mn/CH 3 looses additional 2-methylpyrazine ligands and transforms into a new compound of composition Mn(NCS) 2 (2-methylpyrazine) ( 4 - Mn/CH 3 ). Compound 4 - Mn/Cl is isotypic to its cobalt(II) analog and 4 - Mn/CH 3 is isotypic to Cd(NCS) 2 (2-methylpyrazine) reported recently and therefore, both structures were refined by the Rietveld method. The crystal structures of both compounds are strongly related. They consists of dimeric units, in which each two manganese cations are linked by pairs of μ-1,3-bridging thiocyanato anions, which are further connected into layers by single μ-1, 3-bridging anionic ligands. In contrast to 4 - Mn/Cl , in 4 - Mn/CH 3 these layers are further linked into a 3D coordination network by the 2-methylpyrazine ligands. Magnetic measurements reveal that 1 - Mn/Cl , 1 - Mn/CH 3 , and 3 - Mn/CH 3 shows only Curie- or Curie-Weiss paramagnetism, whereas 4 - Mn/Cl and 4 - Mn/CH 3 shows antiferromagnetic ordering at T N = 22.9 K and at 26.5 K. The results of these investigations are compared with those obtained for related compounds.

Description: . Black platelets of Bi 39.67(7) Ru 2 Br 35.0(2) were crystallized from a melt of Bi, BiBr 3 , and Ru. In the tetragonal crystal structure [ P 4/ mbm , a = 1311.92(6) pm, c = 3018.2(4) pm at 155(5) K], cluster cations [(Bi 8 2+ )Ru 2+ (Bi 8 2+ )] are embedded in a matrix of disordered bromido-bismuthate(III) groups. A thorough analysis of the disorder in the anionic part enabled the unambiguous assignment of the cluster charge. The η 4 -coordination of the two Bi 8 2+ square antiprisms to the Ru II atom in the sandwich complex resembles the bonding of Bi 5 + and Bi 8 2+ in the clusters [(Bi 5 + )Ru + (Bi 4 Br 4 )Ru + (Bi 5 + )] and [(Bi 8 2+ )Ru + (Bi 4 Br 4 )Ru + (Bi 5 + )] as well as of Bi 4 2– in 1 ∞ [(Bi 4 2– )Ru + (Bi 4 Br 4 )Ru + ]. By combining crystal chemical considerations for all mentioned compounds and using quantum chemical calculations, a common bonding scheme for the coordination compounds of bismuth polycations and polyanions was established. The η 4 -coordinating bismuth polycations and polyanions act as six electron donors, comparable to nido -carborane ligands, Zintl anions E 9 4– and E 5 6– ( E = Si to Pb), cyclopentadienyl ligands, or the cyclobutadiene dianion. The electron count for the transition metal is 18 in all finite clusters.

Description: . Previous attempts to synthesize and isolate (thiobisphenolate) vanadium(V) dioxido complexes had always provided their dimers containing [O=V(μ-O) 2 V=O] 2+ cores, and these also dominate the solution reactivity. Hence, the behavior of their parent monomers, which represent the major species in solution, has remained uncertain. Herein we report the development of a synthetic route that allowed for the successful isolation, spectroscopic investigation, and structural characterization of the monomer PPh 4 [ S LVO 2 ] ( 3 ) [ S L 2– = 2′2-thiobis(2, 4-di- tert -butylphenolate)]. For this purpose PPh 4 [ S LVOCl 2 ] ( 1 ) had to be accessed first in order to convert it to the ethoxido compound PPh 4 [ S LVO(OEt) 2 ] ( 2 ), which is more prone to hydrolysis. Treatment of 2 with stoichiometric amounts of water followed by immediate cooling to –30 °C led to crystals of 3 . After its dissolution NMR spectra were recorded that were identical with those obtained after dissolution of its dimer, thus confirming the monomer/dimer equilibrium postulated previously. The molecular structure of 3 revealed the absence of a V ··· S interaction, which, however, stabilizes its dimer, and thus suggested the employment of a bisphenolate ligand lacking a bridging sulfur atom to obtain an analogue, which does not undergo dimerization in solution. In Et L 2– the sulfur atom is replaced by an ethylmethine unit and indeed the corresponding complex NBu 4 [ Et LVO 2 ] ( 4 ) proved to be stable as a monomer. Investigation of its potential as a catalyst for the oxidative dehydrogenation of 9-fluorenol confirmed a much lower reactivity in comparison to dimeric complexes, which is discussed.

Description: Two complexes, cis -[MnL 2 (NCS) 2 ] ( 1 ) and cis -[ZnL 2 (NCS) 2 ] ( 2 ) with asymmetrical substituted triazole ligands [L = 3, 4-dimethyl-5-(2-pyridyl)-1, 2, 4-triazole], were synthesized and characterized by elemental analysis, UV/Vis and FT-IR spectroscopy as well as thermogravimetric analyses (TGA), powder XRD, and single-crystal X-ray diffraction. In the complexes, each L molecule adopts a chelating bidentate mode by the nitrogen atoms of pyridyl and triazole. Both complexes have a similar distorted octahedral [ M N 6 ] core ( M = Mn 2+ and Zn 2+ ) with two NCS – ions in the cis position.

Description: . The multi-shaped amorphous alloy (Ni-B) powders were prepared by complexing reduction route using sodium borohydride (NaBH 4 ) as reductant with assistance of ultrasonic wave. The selected complexants, i.e. water, ammonia, salicylic acid, and ethylene diamine tetraacetic acid (EDTA) possess sequentially escalating complexation ability. The chemical composition and shapes of the product samples obtained under different conditions were characterized by X-ray powder differaction, selected area electron diffraction, and transmission electron microscope. The influence of reaction conditions such as the types of Ni-B, temperatures, NaBH 4 concentrations, and sodium hydroxide (NaOH) content on the hydrogen generation rate of hydrolysis of NaBH 4 solution were investigated in detail. The results show that the as-prepared Ni-B powders all belong to amorphous alloy with variable element contents, and the Ni-B sample prepared from EDTA complexation, possessing the best fineness and dispersity, has the strongest catalytic activity. The mean apparent activation energy of the hydrolysis reaction is 64.90 kJ · mol –1 . The NaBH 4 concentration has little impact on hydrogen generation rate, implying that the catalytic hydrolysis of NaBH 4 solution should be the pseudo zero-order reaction. Keeping the NaOH content at below 5 % could inhibit the hydrolysis of NaBH 4 solution, but the NaOH contents from 10 % to 15 % will significantly promote the hydrolysis rate of NaBH 4 . The hydrolysis reaction mechanisms, especially the effect of NaOH content on the hydrolysis reaction were also analyzed.

Description: [1]  Determining the scale-length, magnitude, and distribution of heterogeneity in the lowermost mantle is crucial to understanding whole mantle dynamics, and yet it remains a much debated and ongoing challenge in geophysics. Common shortcomings of current seismically-derived lowermost mantle models are incomplete raypath coverage, arbitrary model parameterization, inaccurate uncertainty estimates, and an ad hoc definition of the misfit function in the optimization framework. In response, we present a new approach to global tomography. Apart from improving the existing raypath coverage using only high quality cross-correlated waveforms, the problem is addressed within a Bayesian framework where explicit regularization of model parameters is notrequired. We obtain high resolution images, complete with uncertainty estimates, of the lowermost mantle P-wave velocity structure using a hand-picked dataset of PKPab-df, PKPbc-df, and PcP-P differential traveltimes. Most importantly, our results demonstrate that the root mean square of the P-wave velocity variations in the lowermost mantle is approximately 0.87%, which is three times larger than previous global-scale estimates.

Description: The intermetallic compounds Sr 2 Au 6.52 Zn 2.48 , Sr 2 Au 6 Zn 3 , and Sr 2 Au 6 Ga 3 were obtained by induction melting of the elements in sealed tantalum tubes. Their structures were studied by X-ray diffraction on powders and refined from single crystal diffraction data: R c , a = 844.5(2), c = 2187.7(5) pm, wR 2 = 0.0411, 936 F 2 values and 20 variables for Sr 2 Au 6.52 Zn 2.48 ; a = 841.6(2), c = 2191.5(7) pm, wR 2 = 0.0126, 587 F 2 values and 19 variables for Sr 2 Au 6 Zn 3 ; and a = 841.9(2), c = 2191.1(7) pm, wR 2 = 0.0199, 660 F 2 values and 19 variables for Sr 2 Au 6 Ga 3 . The gold substructures of Sr 2 Au 6 Zn 3 and Sr 2 Au 6 Ga 3 can be considered as diamond polytypes with 6R stacking sequences (287–304 pm Au–Au in Sr 2 Au 6 Zn 3 ). The cavities formed by this network are filled in an ordered manner by strontium atoms and Zn 3 (281 pm Zn–Zn), respectively Ga 3 (286 pm Ga–Ga) triangles in a 2:1 ratio. Consequently one can describe the Sr 2 Au 6 Zn 3 and Sr 2 Au 6 Ga 3 structures as ordered substitution variants of the Zintl phase CaIn 2 . This structural relationship is discussed on the basis of a group-subgroup Scheme. Sr 2 Au 6.52 Zn 2.48 shows Zn/Au mixing on the triangle.

Description: The templated borate, [C 9 H 14 N] · [B 5 O 6 (OH) 4 ], was synthesized under hydrothermal conditions. Single crystal X-ray diffraction techonology reveals that it crystallizes in the triclinic system, space group P (No. 2). The material was also characterized by element analysis, Fourier transform infrared spectroscopy (FTIR), powder X-ray diffraction (PXRD), thermogravimetric and differential thermal analysis (TG-DTA), and luminescence spectroscopy. The compound consisted of isolated pentaborate [B 5 O 6 (OH) 4 ] – and N -butylpyridinium cations [C 9 H 14 N] + . The [B 5 O 6 (OH) 4 ] – anions are connected together by hydrogen bonds to form a three-dimensional framework, in which [C 9 H 14 N] + cations are located in. [C 9 H 14 N] · [B 5 O 6 (OH) 4 ] exhibits tunable luminescence emission at 415–458 nm by means of heating treatment from 100 to 300 °C.

Description: Two alkylimido derivatives of hexamolybdate, (Bu 4 N) 2 [Mo 6 O 18 (≡N- o -COOCH 3 C 6 H 4 )] ( 1 ) and (Bu 4 N) 2 [Mo 6 O 18 (≡N- o -COOCH 2 CH 3 C 6 H 4 )] ( 2 ), were synthesized in high purity and good yields by the reaction of [(C 4 H 9 ) 4 N] 4 [α-Mo 8 O 26 ] and methyl anthranilate or ethyl- o -aminobenzoate hydrochloride with N , N ′-dicyclohexylcarbodiimide (DCC) as a dehydrating agent in dry acetonitrile solution, which were characterized by elemental analyses, IR, UV/Vis, and 1 H NMR spectroscopy as well as ESI-MS, and single-crystal X-ray diffraction study. Compound 1 crystallizes in the monoclinic space group P 2 1 / n with one-dimensional chain structure via intramolecular hydrogen bond. Compound 2 also crystallizes in the monoclinic space group P 2 1 / n with dimer structure by intramolecular hydrogen bonds and π–π interactions between the pairs of cluster anions.

Description: The cover picture shows the frontispieces of all articles published in this Special Issue with research reports from DFG priority program 1178 “Experimental Electron Density as Key to Understanding Chemical Interactions”, highlighting the diverse range of chemistry that is covered herein. Biological processes that determine the effects of drugs consist on a certain interaction between agent and receptor. This molecular recognition is influenced by the electron density distribution. Analysis of these processes enables the rational synthesis of drugs. Electron density measurements are moreover significant for the design of advanced materials with specific features, e.g. the development of new pigments. Thus, color, stability, and durability can be tuned by modifying the electron density. Selected substance classes used in chemical synthesis, drug design and material science were analyzed and their binding and recognition processes were studied and quantified by means of electron density measurements.

Description: [1]  The Dzhungarian strike-slip fault of Central Asia is one of a series of long, NW-SE right-lateral strike-slip faults that are characteristic of the northern Tien Shan region, and extends over 300 km from the high mountains into the Kazakh Platform. Our field-based and satellite observations reveal that the Dzhungarian fault can be characterised by three 100 km long sections based on variation in strike direction. Through morphological analysis of offset streams and alluvial fans, and through OSLdating, we find that the Dzhungarian fault has a minimum average late Quaternary slip rate of 2.2 ± 0.8 mm/yr and accommodates N-S shortening related to the India-Eurasia collision. This shortening may also be partly accommodated by counter-clockwise rotation about a vertical axis. Evidence for a possible paleo-earthquake rupture indicates that earthquakes up to at least Mw 7 can be associated with just the partitioned component of reverse slip on segments of the central section of the fault up to 30 km long. An event rupturing longer sections of the Dzhungarian fault has the potential to generate greater magnitude earthquakes ( Mw 8), however long time periods (e.g. thousands of years) are expected in order to accumulate enough strain to generate such earthquakes.

Description: . Reactions of the coordinatively unsaturated complexes [Fe 2 (μ-P R 2 )(μ-P R ′ 2 )(CO) 5 ] [ R = R ′ = t Bu ( 1 ); R = t Bu, R ′ = Cy ( 2 )] with nitric oxide in toluene at elevated temperatures were investigated. Thus, the new complexes [Fe 2 (μ-P t Bu 2 ) 2 (NO) 4 ] ( 3 ) and [Fe 2 (μ-P t Bu 2 )(μ-PCy 2 )(NO) 4 ] ( 4 ) were obtained in good yields. The molecular structure of 3 was confirmed by X-ray diffraction study. Compound 4 was also prepared from the coordinatively saturated species [Fe 2 (μ-P t Bu 2 )(μ-PCy 2 )(CO) 6 ] ( 2a ) with nitric oxide in refluxing toluene. Further closely related reactions at 60 °C with the complex 1 and [FeRu(μ-P t Bu 2 ) 2 (CO) 5 ] ( 5 ), respectively, were investigated using preliminary crystal structure determination results.

Description: Two new materials of the composition ({CH 3 (CH 2 ) 15 (CH 3 ) 2 S} + ) 2 [CoBr 4 ] 2– ( 1 ) and ({CH 3 (CH 2 ) 15 (CH 3 ) 2 S} + ) 2 [CuBr 4 ] 2– ( 2 and 3 ), of which the latter exists in two polymorphs, were synthesized. The materials display the synthetically targeted structures, comprising of layers of complex metal ions and layers of long-chain sulfonium cations. The crystal structures of the materials were determined. The interlayer distances are around 24 Å, with metal–metal distances about 8 Å. The magnetic properties of 1 were investigated, and the material is paramagnetic. ({CH 3 (CH 2 ) 15 (CH 3 ) 2 S} + ) 2 [CuBr 4 ] 2 is polymorphic. Both polymorphs crystallize with triclinic symmetry.

Description: [1]  We performed shock compression experiments on preheated forsterite liquid (Mg 2 SiO 4 ) at an initial temperature of 2273 K and have revised the equation of state (EOS) that was previously determined by shock melting of initially solid Mg 2 SiO 4 (300 K). The linear Hugoniot, U S  = 2.674 ± 0.188 + 1.64 ± 0.06 u p km/s, constrains the bulk sound speed within a temperature and composition space as yet unexplored by 1-bar ultrasonic experiments. We have also revised the EOS for enstatite liquid (MgSiO 3 ) to exclude experiments that may have been only partially melted upon shock compression and also the EOS for anorthite liquid, which now excludes potentially un-relaxed experiments at low pressure. The revised fits and the previously determined EOS of fayalite and diopside were used to produce isentropes in the multicomponent CaO-MgO-Al 2 O 3 -SiO 2 -FeO system at elevated temperatures and pressures. Our results are similar to those previously presented for peridotite and simplified “chondrite” liquids such that regardless of where crystallization first occurs, the liquidus solid sinks upon formation. This process is not conducive to the formation of a basal magma ocean. We also examined the chemical and physical plausibility of the partial melt hypothesis to explain the occurrence and characteristics of ultralow velocity zones. We determined that the ambient mantle cannot produce an equilibrium partial melt and residue that is sufficiently dense to be a ULVZ mush. The partial melt would need to be segregated from its equilibrium residue and combined with a denser solid component to achieve a sufficiently large aggregate density.

Description: [1]  High resolution sparker and crustal-scale airgun seismic reflection data, coupled with repeat bathymetric surveys, document a region of repeated coseismic uplift on the portion of the Alaska subduction zone that ruptured in 1964. This area defines the western limit of Prince William Sound. Differencing of vintage and modern bathymetric surveys shows that the region of greatest uplift related to the 1964 Great Alaska earthquake was focused along a series of sub-parallel faults beneath Prince William Sound and the adjacent Gulf of Alaska shelf. Bathymetric differencing indicates that 12 m of coseismic uplift occurred along two faults that reached the sea floor as submarine terraces on the Cape Cleare bank southwest of Montague Island. Sparker seismic reflection data provide cumulative Holocene slip estimates as high as 9 mm/yr along a series of splay thrust faults within both the inner wedge and transition zone of the accretionary prism. Crustal seismic data show that these megathrust splay faults root separately into the subduction zone décollement. Splay fault divergence from this megathrust correlates with changes in mid-crustal seismic velocity and magnetic susceptibility values, best explained by duplexing of the subducted Yakutat terrane rocks above Pacific plate rocks along the trailing edge of the Yakutat terrane. Although each splay fault is capable of independent motion, we conclude that the identified splay faults rupture in a similar pattern during successive megathrust earthquakes and that the region of greatest seismic coupling has remained consistent throughout the Holocene.

Description: [1]  We perform a time-lapse analysis of Rayleigh and Love wave anisotropy above an underground gas storage facility in the Paris Basin. The data were acquired with a three-component seismic array deployed during several days in April and November 2010. Phase velocity and back azimuth of Rayleigh and Love waves are measured in the frequency range 0.2-1.1 Hz using a three-component beamforming algorithm. In both snapshots, higher surface wave modes start dominating the signal above 0.4 Hz with a concurrent increase in back azimuth ranges. We fit anisotropy parameters to the array detections above 0.4 Hz using a bootstrap approach which also provides estimation uncertainty and enables significance testing. The isotropic phase velocity dispersion for Love and Rayleigh waves match for both snapshots. We also observe a stable fast direction of NNW-SSE for Love and Rayleigh waves which is aligned with the preferred orientation of known shallow (〈300 m) and deeper (~1000 m) fault systems in the area, as well as the maximum horizontal stress orientation. At lower frequencies corresponding to deeper parts of the basin, the anisotropic parameters exhibit higher magnitude in the November data. This may perhaps be caused by the higher pore-pressure changes in the gas reservoir in that depth range.

Description: [1]  Eruptive activity at the summit of Kilauea Volcano, Hawaii beginning in 2010 and continuing to the present time is characterized by transient outgassing bursts accompanied by very long period (VLP) seismic signals triggered by rockfalls from the vent walls impacting a lava lake in a pit within the Halemaumau pit crater. We use raw data recorded with a 11-station broadband network to model the source mechanism of signals accompanying two large rockfalls on August 29, 2012 and two smaller average rockfalls obtained by stacking over all events with similar waveforms to improve the signal-to-noise ratio. To determine the source centroid location and source mechanism, we minimize the residual error between data and synthetics calculated by the finite difference method for a point source embedded in a homogeneous medium that takes topography into account. We apply a new waveform inversion method that accounts for the contributions from both translation and tilt in horizontal seismograms through the use of Green's functions representing the seismometer response to translation and tilt ground motions. This method enables a robust description of the source mechanism over the period range 1-1000 s. The VLP signals associated with the rockfalls originate in a source region ~1 km below the eastern perimeter of the Halemaumau pit crater. The observed waveforms are well explained by a simple volumetric source with geometry composed of two intersecting cracks including an east striking crack (dike) dipping 80 ∘ to the north, intersecting a north striking crack (another dike) dipping 65 ∘ to the east. Each rockfall is marked by a similar step-like inflation trailed by decaying oscillations of the volumetric source, attributed to the efficient coupling at the source centroid location of the pressure and momentum changes induced by the rock mass impacting the top of the lava column. Assuming a simple lumped parameter representation of the shallow magmatic system, the observed pressure and volume variations can be modeled with the following attributes: rockfall volume (200 − 4500 m 3 ), length of magma column (120-210 m), diameter of pipe connecting the Halemaumau pit crater to the subjacent dike system (6 m), average thickness of the two underlying dikes (3 – 6 m), and effective magma viscosity (30–210 Pa s). Most rockfalls occur during episodes of sustained deflation of the Kilauea summit. The mass loss rate in the shallow magmatic system is estimated to be 1400  −  15, 000 kg s − 1 based on measurements of the temporal variation of VLP period in the two large rockfalls that occurred on August 29, 2012.

Description: Single crystals of Rb 2 H 2 P 2 O 6 · 2H 2 O could be obtained from aqueous solutions of hypodiphosphoric acid and rubidium carbonate. Its crystal structure was determined by X-ray diffraction and it crystallizes in the monoclinic space group P 2 1 / c with Z = 4. The salt-like title compound consists of [H 2 P 2 O 6 ] 2– units in staggered P 2 O 6 -skeleton conformation, Rb + cations, and H 2 O molecules, held together by intermolecular hydrogen bonds of the type O ··· O. The vibrational spectra (IR/FIR and Raman) of the rubidium salt were recorded and an assignment of the vibrational modes is proposed based on the point group C 2 h for the P 2 O 6 -skeleton of the anion. The thermal behavior of Rb 2 H 2 P 2 O 6 · 2H 2 O is dominated by a complex TG decay indicating a simultaneous H 2 O delivery coupled with a disproportionation of [H 2 P 2 O 6 ] 2– , what is also supported by Raman spectra of heated samples.

Description: Three metal coordination polymers {[Co(L) 2 (H 2 O) 2 ] 2+ · 2NO 3 – } n ( 1 ), {[Mn(L) 2 (H 2 O) 2 ] 2+ · 2Cl – · 3H 2 O} n ( 2 ), and [ZnL(ba) 2 ] n ( 3 ) [L = 3, 5-bis(imidazole-1-yl)pyridine and Hba = benzoic acid] were synthesized and structurally characterized by IR spectroscopy, elemental analysis, X-ray powder diffraction, and X-ray single crystal diffraction. Complex 1 shows a one-dimensional (1D) chain structure. Adjacent chains are connected by hydrogen bonding and nitrate groups to form a 3D network. Complex 2 features a 2D layer structure. A three-dimensional network is constructed through the cluster consisting of two chloride ions and three water molecules. Complex 3 shows a 1D zigzag chain structure that further twists together to form a 3D network. The X-ray powder diffraction patterns were compared with the simulated ones. Moreover, the luminescent properties of 1 – 3 were investigated in the solid state at room temperature, and the thermogravimetric analyses were carried out to study the thermal stability of the three complexes.

Description: . The reactions of FeCl 3 · 6H 2 O and 2-(2′-hydroxyphenyl)-2-thiazoline as a bidentate O-N donor thiazoline ligand (thoz) afford a five-coordinate Fe III complex [Fe(thoz) 2 Cl] with a distorted square pyramidal configuration. Complex [Fe(thoz) 2 Cl] was isolated as air-stable crystalline solids and fully characterized, including by single-crystal X-ray structure analysis. Complex [Fe(thoz) 2 Cl] shows very efficient reactivity in the oxidation of sulfides to their corresponding sulfoxides using urea hydrogen peroxide (UHP) as the oxidant at room temperature in air.

Description: Two copper(I) complexes of compositions [Cu(HL)I] 2 · EtOH ( 1 ) and [Cu(HL) 3 ]I · MeOH ( 2 ) were synthesized via the reactions of HL [HL = 2(4, 5-diphenyl-1 H -imidazol-2-yl)pyridine] and CuI in EtOH and MeOH, respectively, under solvothermal conditions. The complexes were characterized by X-ray single crystal diffraction, IR spectroscopy, and elemental analysis. Compounds 1 and 2 are catalytically active towards ketalization reaction, giving various ketals under mild conditions.

Description: Mineral samples from the Prasolovskoe epithermal Au-Ag deposit, Russia, were investigated via transmission electron microscopy (TEM). One component was identified as the mineral kurilite Ag 8 Te 3 Se according to the data obtained from electron diffraction (ED) and Fourier transform analyses of high resolution micrographs. Micrometer-sized grains of kurilite were found next to other noble metal chalcogenide domains like the hessite-type. The EDX microprobe analyses of the kurilite domains were determined with the chemical composition Ag 7.9 Au 0.1 Te 2.9 Se 1.0 which is consistent with kurilite doped by gold. Additionally noble metal polychalcogenidehalides (NMPH) were identified via ED. Monoclinic and tetragonal polymorphs of Ag 5 Te 2 Cl were observed for the first time in a mineral sample. One additional component, whose composition equates the kurilite-type component with regard to Ag, Au, Te, and Se but with a marginal chlorine component, crystallizes in a structure type known from synthetic NMPH, namely Ag 23 Te 12 X (X = Cl, Br). This phase as well as the phases Ag 10 Te 4 Br 3 and Ag 20 Te 10 Br 2 was found next to each other in an also investigated synthetic sample.

Description: [1]  On 5 September 2012, a large thrust earthquake (M w 7.6) ruptured a densely-instrumented seismic gap on the shallow-dipping plate boundary beneath the Nicoya Peninsula, Costa Rica. Ground motion recordings directly above the rupture zone provide a unique opportunity to study the detailed source process of a large shallow megathrust earthquake using very nearby land observations. Hypocenter relocation using local seismic network data indicates that the event initiated with small emergent seismic waves from a hypocenter ~10 km offshore, 13 km deep on the megathrust. A joint finite-fault inversion using high-rate GPS, strong-motion ground velocity recordings, GPS static offsets, and teleseismic P waves reveals that the primary slip zone (slip 〉 1 m) is located beneath the peninsula. The rupture propagated down-dip from the hypocenter with a rupture velocity of ~3.0 km/s. The primary slip zone extends ~70 km along strike and ~30 km along dip, with an average slip of ~2 m. The associated static stress drop is ~3 MPa. The seismic moment is 3.5 x 10 20  Nm, giving M w  = 7.6. The co-seismic large-slip patch directly overlaps an onshore inter-seismic locked region indicated by geodetic observations, and extends down-dip to the intersection with the upper plate Moho. At deeper depths, below the upper plate Moho, seismic tremor and low frequency earthquakes have been observed. Most tremor locates in adjacent areas of the megathrust that have little co-seismic slip; a region of prior slow slip deformation to the southeast also has no significant co-seismic slip or aftershocks. An offshore locked patch indicated by geodetic observations does not appear to have experienced co-seismic slip, and aftershocks do not overlap this region, allowing the potential for a comparable size rupture offshore in the future.

Description: [1]  Seismic shear waves emitted by earthquakes can be modeled as plane (transverse) waves. When entering an anisotropic medium they can be split into two orthogonal components moving at different speeds. This splitting occurs along an axis, the fast polarization, that is determined by geologic conditions. We present here a comprehensive analysis of the Silver and Chan (1991) method, used to obtain shear wave splitting parameters, comprising theoretical derivations and statistical tests of the assumptions used to construct the standard errors. We find discrepancies in the derivations of equations in their article, with the most important being a mistake in how the standard errors are calculated. Our simulations suggest that the degrees of freedom are being overestimated by this method and consequently the standard errors are too small. Using a set of S waveforms from very similar shallow earthquakes on Reunion Island, we perform a statistical analysis on the noise of these replicates and find that the assumption of Gaussian noise does not hold. Further, the properties of background noise differ substantially from the noise obtained from the shear wave splitting analysis. However, we find that the standard errors for the fast polarization are comparable to the spread in the fast polarization parameters. Delay time errors appear to be comparable to delay time estimates once cycle skipping is accounted for. Future work using synthetic seismograms with simulated noise should be conducted to confirm this is the case for earthquakes in general.

Description: [1]  The sliver strike-slip Great Sumatra Fault (GSF) traverses mainland Sumatra from the Sunda Strait in the southeast to Banda Aceh in the northwest, and defines the present day plate boundary between the Sunda Plate in the north and the Burmese Sliver Plate in the south. It has been well studied on mainland Sumatra but poorly north of Banda Aceh in the Andaman Sea. Here we present deep seismic reflection images along the northward extension of the GSF over 700 km until it joins the Andaman Sea Spreading Centre and we interpret these images in the light of earthquake, gravity, and bathymetry data. We find that the GSF has two strands between Banda Aceh and Nicobar Island: a transpression in the south and a deep narrow active rift system in the north dotted with volcanoes in the center, suggesting that the volcanic arc is coincident with rifting. Further north of Nicobar Island, an active strike-slip fault, the Andaman-Nicobar Fault, cuts through a rifted deep basin until its intersection with the Andaman Sea Spreading Centre. The volcanic arc lies just east of the rift basin. The western margin of this basin seems to be a rifted continental margin, tilted westward, and flooring the Andaman-Nicobar forearc basin. The Andaman-Nicobar forearc basin is bounded in the west by backthrusts similar to the West Andaman and Mentawai faults. The cluster of seismicity after the 2004 great Andaman-Sumatra earthquake just north of Nicobar Island coincides with the intersection of two strike-slip fault systems.

Description: [1]  The Japan Tohoku-Oki earthquake (9.0 Mw) of 11 March 2011 has left signatures in the Earth's gravity field that are detectable by data of the GRACE mission. Because ESA's satellite gravity mission GOCE – launched in 2009 – aims at high spatial resolution, its measurements could complement the GRACE information on coseismic gravity changes, although time-variable gravity was not foreseen as goal of the GOCE mission. We modeled the coseismic earthquake geoid signal and converted this signal to vertical gravity gradients at GOCE satellite altitude. We combined the single gradient observations in a novel way reducing the noise level, required to detect the coseismic gravity change, subtracted a global gravity model, and applied tailored outlier detection to the resulting gradient residuals. Furthermore, the measured gradients were along-track filtered using different gradient bandwidths where in the space domain Gaussian smoothing has been applied. One year periods before and after earthquake occurrence have been compared with the modeled gradients. The comparison reveals that the earthquake signal is well above the accuracy of the vertical gravity gradients at orbital height. Moreover, the obtained signal from GOCE shows a 1.3 times higher amplitude compared with the modeled signal. Besides the statistical significance of the obtained signal, it has a high spatial correlation of ~0.7 with the forward modeled signal. We conclude therefore that the coseismic gravity change of the Japan Tohoku-Oki earthquake left a statistically significant signal in the GOCE measured gravity gradients.

Description: [1]  The Ninetyeast Ridge (NER), one of the longest linear volcanic features on the Earth, offers an excellent opportunity of understanding the isostatic response to the interactions of mantle plume with the migrating mid-ocean ridge. Bathymetry, geoid and gravity (ship-borne and satellite) data along 72 closely spaced transects and 17 overlapping grids on the NER are analyzed and modeled to determine the effective elastic thickness ( Te ) beneath the entire ridge. The results of 2-D and 3-D flexural modeling of the NER show large spatial variations in Te values ranging from 4 to 35 km, suggesting that the ridge was compensated along its length by different isostatic mechanisms. The southern (south of 22°S latitude) and northern (north of 2°N latitude) parts of the NER have Te values of 〉10 and 〉23 km, respectively, revealing that the southern part was emplaced on a lithosphere of intermediate strength possibly on flank of the Indian plate, whereas the northern part was emplaced in an intraplate setting. In contrast, in the central part of the NER (between latitudes 22°S and 2°N), highly variable Te values (4–22 km) are estimated. The scattered Te values in the central NER suggest that this part may have evolved due to the occurrence of more frequent ridge jumps caused by the interaction of Kerguelen hot spot with rapid northward migration of the Wharton spreading ridge. Residual Mantle Bouguer Anomaly (RMBA) map of the NER and adjacent basins reveals that the entire length of the NER is associated with a significant negative anomaly up to 200 mGal, indicating the presence of thickened crust or less dense mantle beneath the ridge. 3-D crustal thickness map of the NER, generated by inversion of the RMBA data, shows a thick crust ranging from 15 to 19 km. The present study clearly shows that NER possesses a highly segmented isostatic pattern with the occurrence of sub-crustal underplating or sub-surface loading.

Description: [1]  We conducted deep-sea magnetic measurements using autonomous underwater vehicles in the Bayonnaise knoll caldera, the Izu-Ogasawara island arc, which hosts the large Hakurei hydrothermal field. We improved the conventional correction method applied for removing the effect of vehicle magnetization, thus greatly enhancing the precision of the resulting vector anomalies. The magnetization distribution obtained from the vector anomaly data shows an ∼ 2-km-wide belt of high magnetization, trending NNW–SSE going through the caldera, and a low magnetization zone ∼ 300 m by ∼ 500 m in area, extending over the Hakurei site. Comparison between the results obtained using the vector anomaly and the total intensity anomaly shows that the magnetic field is determined more accurately, especially in areas of sparse data distribution, when the vector anomaly rather than the total intensity anomaly is used. We suggest a geologically motivated model that basaltic volcanism associated with the backarc rifting occurred after the formation of the caldera, resulting in the formation of the high magnetization belt underneath the silicic caldera. The Hakurei hydrothermal field lies in the intersection of the basaltic volcanism belt and the caldera wall fault, suggesting a mechanism that hot water generated by the heat of the volcanic activity has been spouting out through the caldera wall fault. The deposit apparently extends beyond the low magnetization zone, climbing up the caldera wall. This may indicate that hot water rising from the deep through the alteration zone is transported laterally when it comes near the seafloor along fissures and fractures in the caldera wall.

Description: [1]  Using multiple ScS reverberations we examine mantle reflectivity structure beneath northeast China and the northwest Pacific. We find several upper mantle discontinuities, including a melt layer with a mean thickness of 64 km atop the 410-km discontinuity, present on both sides of the subducting slab near the Nankai trench. The transition zone contains a split 520-km discontinuity in several paths, and tomographic images show stagnant slabs at this depth. We believe this may be slab-related based on experimental work (Saikia, A., Frost, D. J., Rubie, D. C., 2008. Splitting of the 520-kilometer seismic discontinuity and chemical heterogeneity in the mantle. Science 319 (5869), 1515–1518). A negative reflector is found in one path beneath the northeast China craton at a depth of 598 km. Mid-mantle reflectors are found in all of our paths and are present throughout a wide depth range (~750 – 1600 km).

Description: [1]  Three-dimensional P - and S -wave velocity (V P , V S ) models and high-resolution earthquake relocations are determined for the New Madrid Seismic Zone using double-difference local earthquake tomography. The data set consists of arrival times and differential times recorded by the Cooperative New Madrid Seismic Network (CNMSN) from 2000-2007 and the 1989-1992 Portable Array Network and Data Acquisition deployment. Waveform cross-correlation derived differential times for the CNMSN data are also incorporated. The velocity solutions are compatible with previous solutions centered on the active arms of seismicity and cover a broader area including mafic intrusions along the margin of the Reelfoot Rift. Major features include elevated V P and V S associated with the mafic plutons and reduced V P and V S along and southeast of the Axial fault (AF), a major arm of seismicity trending along the rift axis. Low V P extends to a depth of at least 20 km along the portion of the AF that extends south of the Missouri bootheel. A locally high V P /V S anomaly imaged along the central portion of the Reelfoot fault is spatially correlated with a significant change in fault trend and is interpreted as a region containing high pore pressure and/or water-filled microcracks.

Description: [1]  We present a catalog of InSAR constraints on deformation that occurred during earthquake sequences in southern Iran between 1992-2011, and explore the implications on the accommodation of large-scale continental convergence between Saudi Arabia and Eurasia within the Zagros Mountains. The Zagros Mountains, a salt-laden fold-and-thrust-belt involving ~10 km of sedimentary rocks overlying Precambrian basement rocks, have formed as a result of ongoing continental collision since 10-20 Ma that is currently occurring at a rate of ~3 cm/yr. We first demonstrate that there is a biased misfit in earthquake locations in global catalogs that likely results from neglect of 3D velocity structure. Previous work involving two M ~ 6 earthquakes with well-recorded aftershocks has shown that the deformation observed with InSAR may represent triggered slip on faults much shallower than the primary earthquake, which likely occurred within the basement rocks (〉10 km depth). We explore the hypothesis that most of the deformation observed with InSAR spanning earthquake sequences is also due to shallow, triggered slip above a deeper earthquake, effectively doubling the moment release for each event. We quantify the effects that this extra moment release would have on the discrepancy between seismically and geodetically constrained moment rates in the region, finding that even with the extra triggered fault slip, significant aseismic deformation during the interseismic period is necessary to fully explain the convergence between Eurasia and Saudi Arabia.

Description: [1]  The identification and evaluation of trigger mechanisms for volcano flank instabilities and/or collapse represent a key issue for risk assessment in densely populated volcanic areas, as well as in long distance settings, particularly in case of island or coastal volcanoes. Here, we address quantitatively the effects of external (seismic) and inner (magmatic) forcing on the stress-strain state associated to flank instabilities at Mt. Etna (Sicily, southern Italy) by means of a 2-D Finite-Difference-Method numerical modelling. Modelled seismic actions include strong near-field, strong far-field and low-magnitude near-field earthquakes. Magmatic actions consider the inner presssure changes induced by energetic lava fountains in the summit crater area, sub-vertical and oblique dyke ascent below the summit area. Model results are validated in light of available monitoring data and recent eruptive activity. Numerical results show that the main strain effects are produced by high-magnitude near-field earthquakes (expected return time of ~10 3  yrs), and by vertical uprise of a magma dyke below the volcano summit area. Maximum displacements in the order of tens of centimetres may involve the summit area, up to some 10 6  m 3 /m over some km laterally. Stress releases up to 10 7  Pa may affect a limited portion of the magmatic conduit, thus favouring major effusive flank eruptions. Major catastrophic events, such as volcano flank collapse, should not be expected by applying, either individually or combined, the aforementioned actions.

Description: [1]  Seismicity closely related to hydrological impacts has been observed in several locations worldwide; particularly in intraplate areas where tectonic stressing rates are small. The triggering mechanism is usually explained by a poroelastic response of the seismogenic crust to surface water flux, leading to pore pressure changes at depth. To explain the earthquake triggering in response of those small stress changes, however, the crust has to be near a critical state in which other transient processes might be significant. One of the prominent examples is the Mt. Hochstaufen in SW Germany, where seismicity is known to vary seasonally. A previous analysis showed that the seismicity in 2002 was highly correlated with model forecasts based on fluid diffusion and rate- and state-dependent frictional nucleation. Here we revisit this case by accounting additionally for poroelastic effects, as well as for thermoelastic and tidal stresses. We also test whether the model can explain the observations of the subsequent eight years between 2003 and 2010. Our analysis confirms that rainfall is the dominant driving force in this region. The model not only fits the year 2002 activity very well, but provides with the same parameters a reasonable fit to the subsequent period, with a probability gain of about 4 per event in comparison to a time-independent Poisson model.

Description: ABSTRACT [1]  The absolute magnitude of stress in the crust and the shear strength of faults are poorly known, yet fundamental quantities, in lithospheric dynamics. While stress magnitude cannot be measured directly, deviatoric stress state can be inferred indirectly from focal mechanism solutions collected before and after an earthquake. We extend a standard stress inversion for normalized stresses to invert for the 3D spatial distribution of absolute deviatoric stress and variation of fault strength with depth using focal mechanism solutions and coseismic stress changes produced by large earthquakes. We apply the method to the 2011 M9 Tohoku-oki, Japan earthquake. The northern Japan forearc crust between 5 and 15 km depth appears to be weak with fault strength of 40–90 MPa, consistent with a coefficient of friction of 0.2-0.5. The M9 Tohoku-oki coseismic stress change was large enough, relative to the ambient stress, to rotate the principal stress directions typically ~20° in the upper 20 km of the crust. The data from Japan require a heterogeneous ambient deviatoric stress field with short wavelength (~20-50 km) fluctions in principal stress orientations.

Description: [1]  We review marine heat flow data along the Nankai Trough and show that observations 〉 30 km seaward of the deformation front are 20% below conductive predictions (129–94 mW m -2 ) but consistent with the global heat flow average for oceanic crust of the same age (16-28 Ma). Heat flow values  〈  30 km seaward of the deformation front are generally 20% higher than conductive predictions. This heat flow pattern is consistent with the advection of heat by fluid flow in the subducting oceanic crust and explains both the high heat flux in the vicinity of the trench, 〉 200 and 〉 140 mW m -2 , and steep landward declines to values of approximately 60 mW m -2 over distances of 65 and 50 km along the Muroto and Kumano transects, respectively. Along the Ashizuri transect the lack of heat flow data preclude a definitive interpretation. We conclude that fluid flow in the subducting oceanic crust leads to temperatures that are generally 25 ° C higher near the toe of the margin wedge and 50 - 100 ° C lower near the downdip limit of the seismogenic zone than estimated by purely conductive models.

Description: Eight chelating resins were synthesized in high yields by supporting 2-aminomethylpyridine, 2, 2′-dipyridylamine, 1, 2-phenylenediamine and 1, 2-ethylenediamine on Merrifield and Wang resins, respectively. These resins were used both as support of reducing complexes and as alkali metal sensors. 16 stable and easy to prepare reducing complexes, derived from the chelating resins and LiBH 4 and NaBH 4 , were prepared in good yields. These complexes showed chemoselectivity to reduce aldehydes in a low molar ratio and short time reactions. The fluorescence-sensing behavior of the chelating resins for alkali metal was studied. The fluorescence response of the materials where 1, 2-phenylenediamine is supported on Merrifield and Wang resins indicate that they behave as sensors for Li + and K + , respectively.

Description: The reaction of Fe 3 (CO) 12 with (C 3 H 5 ) 2 NCS 2 K in THF at room temperature afforded a red-brown solution. Treatment of the thus-obtained solution with MeI and PhCH 2 Br afforded clusters 1 , (μ-MeS)Fe 2 (CO) 6 (μ 4 -S)Fe 2 (CO) 6 (μ-CN(C 3 H 5 ) 2 ), and 2 , (μ-PhCH 2 CO)Fe 2 (CO) 6 (μ 4 -S)Fe 2 (CO) 6 (μ-CN(C 3 H 5 ) 2 ). Their structures were unambiguously determined by X-ray crystallography. Therefore, this methodology provides a novel route for the syntheses of spiro-S Fe/S clusters with aminocarbyne ligands.

Description: This study presents the preparation of 5-azido-3-nitro-1 H -1,2,4-triazole ( 1 ) in both good yield and high purity, starting from commercially available chemicals in a three step synthesis. Furthermore, several metal and nitrogen-rich salts with sodium ( 3 ), potassium ( 4 ), cesium ( 5 ), silver ( 6 ), lead ( 7 ), ammonium ( 8 ), guanidinium ( 9 ), and aminoguanidinium ( 10 ) were prepared by simple acid-base reactions. All compounds were well characterized by various means, including vibrational (IR, Raman) and multinuclear ( 1 H, 13 C, 14 N, 15 N) NMR spectroscopy, mass spectrometry, and DSC. Additionally the structure of 7 was determined by single-crystal X-ray diffraction. The sensitivities towards various outer stimuli (impact, friction, electrostatic discharge) were determined according to BAM standards. The metal salts were tested as potential primary explosives utilizing various preliminary tests.

Description: With Sharpless' and Meldal's discovery of the immensely supportive effect that metal catalysis has on Huisgen's classical 1,3-dipolar cycloaddition, azides (RN 3 ) – long underappreciated in organic synthesis – suddenly got in the focus of attention as most crucial players in sensational ‘click chemistry'. Less noisy though with the same commitment and even a much broader scope of scientific topics and objectives, the inorganic azide chemistry has made just as great strides in the last few decades. This review (Part I) gives an introductory survey of the most important results, and informs about modern developments and general trends. Particular emphasis is placed on the recent successful approaches to highly unstable homoleptic azido metal complexes of the main group and early transition elements, as well as on the enormous structural versatility caused by the ‘flexidentate' N 3 – ligand with its unsurpassed bridging capacities. The presentation in this paper of selected compounds and reactions is meant, in a way, as a prelude to the [3+2]-cycloadditions of metal azides and related species which will be covered in-depths in Part II. A large part of the comments finally deals with applications in fields such as catalysis, high explosive performance or magnetism of metal compounds containing azide, today certainly one of the most attractive research areas world-wide.

Description: The long-chain ligand, 1-phenyl-3-methyl-4-heptanoyl-pyrazol-5-one (HL) and its zinc(II) complex ZnL 2 were synthesized. The structure and the properties of ZnL 2 were characterized by elemental analysis, IR spectroscopy, X-ray diffraction, and thermogravimetric analysis. The zinc ion is five-coordinated in a square-pyramidal environment by four oxygen atoms of the HL ligands in the equatorial plane and one water molecule in the axial position. The water molecule is directly bonded to Zn 2+ and involved in intermolecular hydrogen bonding network. The complex and its corresponding ligand were screened in vitro against some strains of the human pathogenic bacteria. The metal complex exhibits higher antibacterial activity than its corresponding ligand. The complex exhibits purple effect emission as the result of fluorescence from the intraligand emission excited state.

Description: The microporous metal-organic framework Cd 2 (ABTC)(H 2 O)(DMA) 2 · H 2 O · 3DMA ( 1 ) (H 4 ABTC = 3,3′,5,5′-azobenzenetetracarboxylic acid; DMA = N , N ′-dimethylacetamide) was prepared by solvothermal reaction and characterized. X-ray structure analysis revealed that compound 1 is a three-dimensional (3D) open framework with 2D channels. The topology is based on a PtS net, constructed of 4-connected rectangular ABTC 4– units with 4-connected tetrahedral dinuclear Cd 2 (CO 2 ) 4 (H 2 O)(DMA) 2 secondary building units (SBUs). The solid-state excitation-emission spectra showed that the strongest emission peak is at 403 nm upon excitation at λ = 287 nm.

Description: P(2-SHC 6 H 4 ) 3 ( PS 3 H 3 ) reacts with GaMe 3 (1:1) to give GaMe{P(2-SC 6 H 4 ) 2 (2-SHC 6 H 4 )-κ 3 S , S′,P } ( 1 ), which could be deprotonated with NEt 3 to give [NEt 3 H][GaMe{P(2-SC 6 H 4 ) 3 -κ 3 S , S′,P }] ( 2 ). The 1:2 reaction of E (2-SHC 6 H 4 ) 3 [ E = P ( PS 3 H 3 ), As ( AsS 3 H 3 )] with GaMe 3 gave the dinuclear complexes GaMe{ E (2-SC 6 H 4 ) 2 (2-S{GaMe 2 (THF)}C 6 H 4 )-κ 3 S , S′,E } [ E = P ( 3 ), As ( 4 )]. Serendipitous hydrolysis of 4 resulted in small amounts of the hexanuclear gallium hydroxide complex cyclo -{GaMe(μ-OH)} 6 {As(2-SC 6 H 4 ) 3 -κ S , S′,S′′ } 2 ( 5 ). Complexes 1 – 4 were fully characterized, complexes 2 – 5 also by X-ray crystallography.

Description: Topological aspects of the experimental electron density in TiB 2 reconstructed on base of the multipole model are obtained from high-resolution single-crystal X-ray diffraction data. The features of electron density are compared with quantum chemical calculations and analysed in terms of Quantum Theory of Atoms in Molecules for the interpretation of atomic interactions. In spite of some differences in the Laplacian, both experimental and calculated density confirmed two main bonding interactions. The B–B bond critical point suggests a shared-type interaction with pronounced ellipticity in the boron layer, whereas B–Ti bond critical point reveals an interaction intermediate between shared and closed-shell type. Both, theory and experiment indicate a non-structured spherical topology in the penultimate shell of Ti. Integration of the electron density over the atomic basins reveals a charge transfer of 1.1 e (experiment) and 1.4 e (theory) from titanium to boron network, respectively.

Description: The stannides Li 2 CuSn 2 and Li 2 AgSn 2 were synthesized by induction-melting (or in a muffle furnace) of the elements in sealed niobium ampoules. The new phases were characterized by powder X-ray diffraction. The structures of both stannides were investigated by X-ray diffraction on single crystals: Li 2 AuSn 2 type, I 4 1 / amd , a = 442.6(1), c = 1940.9(8) pm, wR 2 = 0.0742, 310 F 2 values for Li 2 CuSn 2 and a = 456.33(9) c = 2018.2(6) pm, wR 2 = 0.0626, 339 F 2 values for Li 2 AgSn 2 with 10 variables for each refinement. The transition metal ( T ) atoms have tetrahedral tin coordination. The T Sn 4 tetrahedra are condensed via common corners forming layers that are further condensed by Sn–Sn bonding, leading to three-dimensional [CuSn 2 ] and [AgSn 2 ] networks which leave distorted hexagonal channels for the lithium atoms. The lithium ions show considerable mobility, with activation energies of 0.29 and 0.47 eV extracted from variable temperature 7 Li solid state NMR spectra. 119 Sn Mössbauer spectra at 78 K show signals at isomer shifts of δ = 2.13(1) mm s –1 for Li 2 CuSn 2 and δ = 2.07(1) mm s –1 for Li 2 AgSn 2 . The signals show electric quadrupolar splitting because of the non spherical environment of the tin nuclei. A minor impurity of β-Sn could be identified in both spectra.

Description: The complexes [Ni 2 (L) 2 ] 2 · H 2 O ( 1 ) and [Cu 2 (L) 2 (H 2 O)] · 2CH 3 OH ( 2 ) were prepared by reaction of the chiral Schiff base ligand N -[(1 R ,2 S )-2-hydroxy-1, 2-diphenyl]-acetylacetonimine (H 2 L) with Ni II and Cu II ions, respectively, aiming to develop economically and environmentally-friendly catalysts for the hydrogenation of ketones. They have a dinuclear skeleton with axial vacant sites. The catalytic effects of the two complexes for hydrogenation of ketones were tested using dihydrogen gas as hydrogen source. They present some catalytic effects in hydrogenation of acetophenone, which has a dependence on the temperature and base used in these reactions. However, no apparent catalytic effects were found for the two complexes in hydrogenation of 4-nitroacetophenone and 4-methylacetophenone. Although the catalytic conversion in these hydrogenation reactions is low, they do represent a kind of cheap and environmentally-friendly hydrogenation catalyst.

Description: Poised to investigate the association of vanadium with physiological substrates in materials capable of exerting anticancer biological activity, pH-specific synthetic chemical reactivity between vanadium and triethyl ammonium acetate/trigonelline in aqueous and mixed organic-aqueous media led to the isolation of three new binary composite materials, namely K 2 [(MeN(+)C 5 H 4 COOH) 2 ][V 10 O 28 H 2 ] · 2H 2 O ( 1 ), [(H 2 N(+)Me 2 ) 4 ][V 10 O 28 H 2 ][Me 3 N(+)CH 2 COO(–)] 2 ( 2 ), and [(Me 3 N(+)CH 2 COOH) 4 ][V 10 O 28 H 2 ][Me 3 N(+)CH 2 COO(–)] 2 · 2H 2 O ( 3 ). 1–3 were characterized by elemental analysis, FT-IR and UV/Vis spectroscopy, Cyclic voltammetry, TGA-DTG, and X-ray crystallography. In all three compounds, the [V 10 O 28 H 2 ] 4– core unit is a common cluster assembly, with the vanadium in the +5 oxidation state. The counteracting cationic assembly in each composite material originates in the betaine starting reagent or the solvent out of which the materials crystallized. Biological activity studies of 1 and 3 in vitro in MCF-7 breast epithelial and A549 lung adenocarcinoma cell cultures show that both materials inhibit the viability of both cell lines in a dose-dependent fashion, in juxtaposition to the behavior of the betaine components present in these materials. Collectively, the herein studies a) reveal the uniquely defined synthetic methodologies and physicochemical properties of the variably assembled [V 10 O 28 H 2 ] 4– core units crystallized into the composite binary polyoxovanadate-betaine lattice structures, b) unravel the distinct cytotoxicity profile of the composite materials toward MCF-7 and A549 cells, and c) attest to their future potential as metallodrugs of pharmacological significance in anticancer activity.

Description: [1]  We investigate whether predictions of mantle structure from tectonic reconstructions are in agreement with a detailed tomographic image of seismic P-wave velocity structure under the Caribbean region. In the upper mantle, positive seismic anomalies are imaged under the Lesser Antilles and Puerto Rico. These anomalies are interpreted as remnants of Atlantic lithosphere subduction and confirm tectonic reconstructions that suggest at least 1100 km of convergence at the Lesser Antilles island arc during the past ~45 Myr. The imaged Lesser-Antilles slab consists of a northern and southern anomaly, separated by a low velocity anomaly across most of the upper mantle, which we interpret as the subducted North America-South America plate boundary. The southern edge of the imaged Lesser Antilles slab agrees with vertical tearing of South America lithosphere. The northern Lesser Antilles slab is continuous with the Puerto Rico slab along the northeastern plate boundary. This results in an amphitheatre-shaped slab and it is interpreted as westward subducting North America lithosphere that remained attached to the surface along the northeastern boundary of the Caribbean plate. At the Muertos Trough, however, material is imaged until a depth of only 100 km, suggesting a small amount of subduction. The location and length of the imaged South Caribbean slab agrees with proposed subduction of Caribbean lithosphere under the northern South America plate. An anomaly related to proposed Oligocene subduction at the Nicaragua rise is absent in the tomographic model. Beneath Panama, a subduction window exists across the upper mantle, which is related to the cessation of subduction of the Nazca plate under Panama since 9.5 Ma and possibly the preceding subduction of the extinct Cocos-Nazca spreading center. In the lower mantle two large anomaly patterns are imaged. The westernmost anomaly agrees with the subduction of Farallon lithosphere. The second lower mantle anomaly is found east of the Farallon anomaly and is interpreted as a remnant of the late Mesozoic subduction of North and South America oceanic lithosphere at the Greater Antilles, Aves ridge and Leeward Antilles. The imaged mantle structure does not allow us to discriminate between an ‘Intra-Americas’ origin and a ‘Pacific origin’ of the Caribbean plate.

Description: [1]  We have measured interseismic deformation across the Ashkabad strike-slip fault using 13 Envisat interferograms covering a total effective timespan of ~30 years. Atmospheric contributions to phase delay are significant and variable due to the close proximity of the Caspian Sea. In order to retrieve the pattern of strain accumulation, we show it is necessary to use data from Envisat's Medium Resolution Imaging Spectrometer (MERIS) instrument, as well numerical weather model outputs from the European Centre for Medium-Range Weather Forecasting (ECMWF), to correct interferograms for differences in water vapour and atmospheric pressure respectively. This has enabled us to robustly estimate the slip rate and locking depth for the Ashkabad fault using a simple elastic dislocation model. Our data are consistent with a slip rate of 5–12 mm/yr below a locking depth of 5.5–17 km for the Ashkabad fault, and synthetic tests support the magnitude of the uncertainties on these estimates. Our estimate of slip rate is 1.25–6 times higher than some previous geodetic estimates, with implications for both seismic hazard and regional tectonics, in particular supporting fast relative motion between the South Caspian Block and Eurasia. This result reinforces the importance of correcting for atmospheric contributions to interferometric phase for small strain measurements. We also attempt to validate a recent method for atmospheric correction based on ECMWF ERA-Interim model outputs alone and find that this technique does not work satisfactorily for this region when compared to the independent MERIS estimates.

Description: [1]  The seafloor within the Perth Abyssal Plain (PAP), offshore Western Australia, is the only section of crust that directly records the early spreading history between India and Australia during the Mesozoic breakup of Gondwana. However, this early spreading has been poorly constrained due to an absence of data, including marine magnetic anomalies and data constraining the crustal nature of key tectonic features. Here, we present new magnetic anomaly data from the PAP that shows that the crust in the western part of the basin was part of the Indian Plate – the conjugate flank to the oceanic crust immediately offshore the Perth margin, Australia. We identify a sequence of M2 and older anomalies in the west PAP within crust that initially moved with the Indian Plate, formed at intermediate half-spreading rates (35 mm/yr) consistent with the conjugate sequence on the Australian Plate. More speculatively, we reinterpret the youngest anomalies in the east PAP, finding that the M0-age crust initially formed on the Indian Plate was transferred to the Australian Plate by a westward jump or propagation of the spreading ridge shortly after M0 time. Samples dredged from the Gulden Draak and Batavia Knolls (at the western edge of the PAP) reveal that these bathymetric features are continental fragments rather than igneous plateaus related to Broken Ridge. These microcontinents rifted away from Australia with Greater India during initial breakup at ~130 Ma, then rifted from India following the cessation of spreading in the PAP (~101-103 Ma).

Description: [1]  We develop a three-step Maximum-A-Posteriori probability (MAP) method for coseismic rupture inversion, which aims at maximizing the a posterior probability density function (PDF) of elastic deformation solutions of earthquake rupture. The method originates from the Fully Bayesian Inversion (FBI) and Mixed linear-nonlinear Bayesian inversion (MBI) methods, shares the same posterior PDF with them, while overcoming difficulties with convergence when large numbers of low-quality data are used and greatly improving the convergence rate using optimization procedures. A highly-efficient global optimization algorithm, Adaptive Simulated Annealing (ASA), is used to search for the maximum of a posterior PDF (" mode " in statistics) in the first step. The second step inversion approaches the " true" solution further using the Monte Carlo Inversion (MCI) technique with positivity constraints, with all parameters obtained from step one as the initial solution. Then slip artifacts are eliminated from slip models in the third step using the same procedure of the second step, with fixed fault geometry parameters. [2]  We first design a fault model with 45°-dip angle and oblique slip, and produce corresponding synthetic InSAR datasets to validate the reliability and efficiency of the new method. We then apply this method to InSAR data inversion for the coseismic slip-distribution of the April 14, 2010 Mw 6.9 Yushu, China earthquake. Our preferred slip model is composed of three segments with most of the slip occurring within 15 km depth and the maximum slip reaches 1.38 m at the surface. The seismic moment released is estimated to be 2.32e + 19 Nm, consistent with the seismic estimate of 2.50e + 19 Nm.

Description: The crystal structures of the alkali aluminium thiohypodiphosphates M I AlP 2 S 6 (M I = Li, Na) are reported. NaAlP 2 S 6 crystallizes in the orthorhombic space group Fdd 2 (no. 43) with a = 8.0400(2), b = 10.9452(2), c = 20.8801(4) Å, and V = 1837.44(7) Å 3 ( Z = 8). It is isostructural with AgAlP 2 S 6 , which is consistent with the similar ionic radii of Na and Ag. In contrast, LiAlP 2 S 6 crystallizes in a different structure type which has not been observed in the large number of thiohypodiphosphates reported so far. It crystallizes in the monoclinic space group C 2/ c (no. 15) with a = 6.783(3), b = 10.365(4), c = 11.776(4) Å, β = 94.399(5)°, and V = 825.46(5) Å 3 ( Z = 4).

Description: We present the synthesis of 7-(diphenylphosphine)-indole 1 ( HPinol ) as a novel mono- and bidentate P - and N, P -ligand and its coordination chemical behaviour towards the d 6 - and d 8 -transition metals rhodium(III), palladium(II) and rhenium(I). The reaction of 1 with [Cp*RhCl 2 ] 2 in a 1:2 molar ratio leads to the formation of the P -coordinated complex [RhCl 2 ( P –( HPinol ))] ( 2 ). In the presence of the weak base NEt 3 , HCl elimination occurs by forming the neutral amido-phosphine chelated complex [RhCl( N, P –( Pinol ))] ( 3 ). The same P - and N, P -coordination is observed for palladium(II), where two ligands 1 coordinate to the metal centre forming the neutral complexes [PdCl 2 ( P – HPinol ) 2 ] ( 4 ) and [Pd( N, P – Pinol ) 2 ] ( 5 ). The reaction of Re(CO) 5 Br in the presence of NEt 3 and PPh 3 delivers the amido-phosphine complex [Re(CO) 3 PPh 3 ( N, P – Pinol )] ( 6 ). All products were characterised by multinuclear NMR spectroscopy, MS and IR spectra as well as elemental analysis. Furthermore, crystal structures of ligand 1 and all complexes 2–6 are presented.

Description: [1]  We conducted total magnetic field and Bouguer gravity measurements to investigate the shallow structure beneath the summit caldera of Kīlauea Volcano, Hawai‘i. Two significant and distinctive magnetic anomalies were identified within the caldera. One is interpreted to be associated with a long-lived pre-historic eruptive centre, the Observatory vent, located ~1 km east of the Hawaiian Volcano Observatory. The second magnetic anomaly corresponds to a set of eruptive fissures that strike northeast from Halema‘uma‘u Crater, suggesting this is an important transport pathway for magma. The Bouguer gravity data were inverted to produce 3D models of density contrasts in the upper 2 km beneath Kīlauea. The models detect 3.0 km 3 of material, denser than 2800 kg m -3 , beneath the caldera that may represent an intrusive complex centred northeast of Halema‘uma‘u. Recent temporal gravity studies indicate continual addition of mass beneath the caldera during 1975–2008 centred west of Halema‘uma‘u and suggest this is due to filling of void space. The growth of a large intrusive complex, apparent cyclical caldera formation, and continual mass addition without inflation, however, can also be explained by extensional rifting caused by the continual southward movement of Kīlauea's unstable south flank.

Description: [1]  The 2006-2007 doublet of M W  〉 8 earthquakes in the Kuril subduction zone caused postseismic transient motion in the asthenosphere, which we observed on the Kuril GPS Array in 2007–2011. Here we show that the Maxwell asthenospheric viscosity that best fits the geodetic data increased by nearly an order of magnitude over the interval of four years, from 2 × 10 17 to 1 × 10 18  Pa s. These effective values of viscosity can be explained by a power-law rheology for which strain rate is proportional to stress raised to a power n  〉 1. The apparent change in viscosity can also be caused by other factors such as coupling between afterslip and viscoelastic flow. The open and intriguing question in connection with postseismic data after the Kuril earthquake doublet is the magnitude of the long-term asthenospheric viscosity, which shall be revealed by continued observations. An asthenosphere with viscosity of about 1 × 10 19  Pa s is favored by the postseismic deformation still observed several decades after the 1960 Chile and 1964 Alaska M W ~9 earthquakes. However, postseismic deformation associated with the 1952 southern Kamchatka M W ~9 earthquake currently is not observed in the northern Kurils, an indication that the long-term asthenospheric viscosity in the Kurils is lower than in Chile and Alaska.

Description: [1]  The region of central Chile offers a unique opportunity to study the links between the subducting Juan Fernandez Ridge, the flat slab, the Double Seismic Zone (DSZ) and the absence of modern volcanism. Here, we report the presence and characteristics of the first observed DSZ within the intermediate-depth Nazca slab using two temporary seismic catalogues (OVA99 and CHARSME). The lower plane of seismicity (LP) is located 20–25 km below the upper plane (UP), begins at 50 km depth and merges with the lower plane at 120 km depth, where the slab becomes horizontal. Focal mechanism analysis and stress tensor calculations indicate that the slab's state of stress is dominantly controlled by plate convergence and overriding crust thickness: Above 60–70 km depth, the slab is in horizontal compression, and below, it is in horizontal extension, parallel to plate convergence, which can be accounted for by vertical loading of the overriding lithosphere. Focal mechanisms below 60–70 km depth are strongly correlated with offshore outer rise bend faults, suggesting the reactivation of pre-existing faults below this depth. The large interplane distances for all Nazca DSZs can be related to the slab's unusually cold thermal structure with respect to its age. Since LPs globally seem to mimic mantle mineral dehydration paths, we suggest that fluid migration and dehydration embrittlement provide the mechanism necessary to weaken the rock and that the stress field determines the direction of rupture.

Description: In the course of investigations relating to magnesia oxysulfate cement the basic magnesium salt hydrate 3Mg(OH) 2 · MgSO 4 · 8H 2 O (3–1–8 phase) was found as a metastable phase in the system Mg(OH) 2 -MgSO 4 -H 2 O at room temperature (the 5–1–2 phase is the stable phase) and was characterized by thermal analysis, Raman spectroscopy, and X-ray powder diffraction. The complex crystal structure of the 3–1–8 phase was determined from high resolution laboratory X-ray powder diffraction data [space group C 2/ c , Z = 4, a = 7.8956(1) Å, b = 9.8302(2) Å, c = 20.1769(2) Å, β = 96.2147(16)°, and V = 1556.84(4) Å 3 ]. In the crystal structure of the 3–1–8 phase, parallel double chains of edge-linked distorted Mg(OH 2 ) 2 (OH) 4 octahedra run along [–110] and [110] direction forming a pattern of crossed rods. Isolated SO 4 tetrahedra and interstitial water molecules separate the stacks of parallel double chains.

Description: [1]  Among the different types of waves embedded in seismic noise, body waves present appealing properties but are still challenging to extract. Here we first validate recent improvements in numerical modeling of microseismic compressional ( P ) body waves and then show how this tool allows fast detection and location of their sources. We compute sources at ~ 0.2 Hz within typical P teleseismic distances (30-90 degrees) from the South California Seismic Network (SCSN) and analyze the most significant discrete sources. The locations and relative strengths of the computed sources are validated by the good agreement with beam-forming analysis. These ~75 noise sources exhibit a highly heterogeneous distribution, and cluster along the usual storm tracks in the Pacific and Atlantic oceans. They are mostly induced in the open ocean, at or near water depths of 2800 and 5600 km, most likely within storms or where ocean waves propagating as swell meet another swell or wind sea. We then emphasize two particularly strong storms to describe how they generate noise sources in their wake. We also use these two specific noise bursts to illustrate the differences between microseismic body- and surface-waves in terms of source distribution and resulting recordable ground motion. The different patterns between body- and surface-waves result from distinctive amplification of ocean wave-induced pressure perturbation and different seismic attenuation. Our study demonstrates the potential of numerical modeling to provide fast and accurate constraints on where and when to expect microseismic body waves, with implications for seismic imaging and climate studies.

Description: [1]  Earthquakes that rupture across steps between faults can be larger than those predicted from individual fault lengths, making understanding multifault events critical to assessing earthquake hazard. Empirical data from earthquake surface ruptures suggest that the distances between faults that rupture together can range from 〈1 km to 5 km. Dynamic and quasi-static models of planar faults determine similar distances. However, studies of interactions between realistic, 3D non-planar faults are few. A general comparison of quasi-static stress perturbations and triggering potentials with mechanical models incorporating either planar or non-planar faults highlight the sensitivity of planar fault models to model parameters and reveal no clear relationship between mean fault slip and triggering potential. More specifically, planar fault models predict triggering across a 3 km extensional step, while models incorporating non-planar faults indicate that a connecting fault is necessary to transfer slip through a 3 km step along the 1992 Landers, California earthquake rupture. The mechanical approach taken captures the stress changes as well as the total stress following fault slip, improving the criterion used to determine triggered failure potential. This underscores the need for additional constraint on fault strength and cohesion. The focus on complex fault geometry restricts analyses to the quasi-static realm, limiting the application of results to fault interactions over the short distances and slow rupture velocities for which the quasi-static stress field is relevant or approximates the dynamic stress field.

Description: [1]  Batch and flow-through experiments were performed on quartz-feldspar granular aggregates and sandstone samples to investigate time-dependent effects of fluid-rock interactions on fluid and rock conductivity, respectively. The experiments were conducted at temperatures up to 164, at confining and pore pressures up to 10 and 5 MPa, respectively, and for up to 136 days. It showed that changes in rock conductivity were unequivocally related to changes in pore fluid conductivity. It is inferred that these changes were dependent on kinetically controlled dissolution reactions between the mineral grains and the fluid. The time-dependent signature of rock conductivity implied a detectable transition from initial dissolution towards some state of equilibrium. The response of rock conductivity to temperature changes followed an Arrhenius-type behavior. An exploratory kinetic evaluation of the conductivity data for sandstone samples yielded an apparent activation energy of approximately 32 kJ/mol. A concurrent chemical fluid analysis showed that this is an integrated value over all reactions occurring in parallel within a sample. These reactions namely concern silica and silicate dissolutionbut also the dissolution of accessory salt minerals. It is concluded that measuring the evolution of rock conductivity in combination with chemical pore fluid analysis constitutes a powerful and quantitative tool for monitoring time-dependent changesin pore fluid chemistry and thus fluid-rock interactions in real time.

Description: [1]  We describe a multi-parameter experiment at Erebus volcano, Antarctica, employing Doppler radar, video, acoustic, and seismic observations to estimate the detailed energy budget of large (up to 40-m-diameter) bubble bursts from a persistent phonolite lava lake. These explosions are readily studied from the crater rim at ranges of less than 500 m, and present an ideal opportunity to constrain the dynamics and mechanism of magmatic bubble bursts that can drive Strombolian and Hawaiian eruptions. We estimate the energy budget of the first second of a typical Erebus explosion as a function of time and energy type, and constrain gas pressures and forces using an analytic model for the expansion of a gas bubble above a conduit that incorporates conduit geometry and magma and gas parameters. The model, consistent with video and radar observations, invokes a spherical bulging surface with a base diameter equal to that of the lava lake. The model has no ad hoc free parameters, and geometrical calculations predict zenith height, velocity and acceleration during shell expansion. During explosions, the energy contained in hot over-pressured gas bubbles is freed and partitioned into other energy types, where by far the greatest non-thermal energy component is the kinetic and gravitational potential energy of the accelerated magma shell (〉10 9 J). Seismic source energy created by explosions is estimated from radar measurements and is consistent with source energy determined from seismic observations. For the generation of the infrasonic signal, a dual mechanism incorporating a terminally disrupted slug is proposed, which clarifies previous models and provides good fits to observed infrasonic pressures. A new and straightforward method is presented for determining gas volumes from slug explosions at volcanoes from remote infrasound recordings.

Description: [1]  We explore the application of GPS data to earthquake early warning and investigate whether the co-seismic ground deformation can be used to provide fast and reliable magnitude estimations and ground shaking predictions. We use an algorithm to extract the permanent static offset from GPS displacement time series and invert for the slip distribution on the fault plane, which is discretized into a small number of rectangular patches. We developed a completely “self-adapting” strategy in which the initial fault plane model is built based on a quick, approximate magnitude estimation, and is then allowed to increase in size based on the evolutionary magnitude estimation resulting from the slip inversion. Two main early warning outputs are delivered in real-time: magnitude and the along-strike extent of the rupture area. These are finally used to predict the expected ground shaking due to the finite source. We tested the proposed strategy by simulating real-time environments for three earthquakes. For the Mw 9.0, 2011 Tohoku-Oki earthquake our algorithm provides the first magnitude estimate of 8.2 at 39 sec after the origin time, and then gradually increases to 8.9 at 120 sec. The estimated rupture length remains constant from the outset at ~360 km. For the Mw 8.3, 2003 Tokachi-Oki earthquake the initial magnitude estimate is 8.5 at 24 sec and drops to 8.2 at 40 sec with a rupture length of 290 km. Finally, for the Mw 7.2, 2010 El Mayor-Cucapah earthquake the magnitude estimate is 7.0 from the outset with a rupture length of 140 km. The accuracy of the ground shaking prediction using the GPS-based magnitude and finite extent is significantly better than existing seismology-based point source approaches. This approach would also facilitate more rapid tsunami warnings

Description: The cover picture shows the synthesis and the molecular structure of a zwitterionic [4.3.0]-bicyclic aluminum-phosphorus compound with annulated C 3 P 2 and Al 2 C 2 PH heterocycles and a 3c-2e Al–H–Al bond. Treatment of the dialkynylphosphine Mes–P(–C=C–CMe 3 ) 2 ( 1 ) with diethylaluminum hydride ( 2 ) in an equimolar ratio afforded a mixture of compounds, in which a [3.2.0]-bicyclic compound 3 with annulated fourmembered AlC 2 P and five-membered P 2 C 3 heterocycles could be identified by NMR spectroscopy. Excess of the hydride 2 yielded small quantities of the zwitterionic [4.3.0]-bicyclic compound 4 , which formally resulted from the unique insertion of a diethylaluminum hydride molecule into the Al–C(vinyl) bond of the strained fourmembered heterocycle of 3 . A six-membered ring is formed which contains an Al–H–Al 3c-2e bond. More details can be found in the Article by Werner Uhl et al. on page 1181 ff.

Description: Using the bis(pyrazolyl)pyridinylmethane ligand α,α,α-bis(1-pyrazolyl)(2-pyridinyl)toluene {(ph)C(pz) 2 (py)} for bioinorganic inspired coordination chemistry studies, we synthesised and structurally characterised three monofacial complexes [{(ph)C(pz) 2 (py)}CoCl 2 ] ( C1 ), [{(ph)C(pz) 2 (py)}CuCl 2 ] ( C2 ), [{(ph)C(pz) 2 (py)}ZnCl 2 ] ( C3 ) and the binuclear halogenido-bridged complexes [{(ph)C(pz) 2 (py)} 2 (μ-Cl) 2 Fe 2 Cl 2 ] ( C4 ) and [{(ph)C(pz) 2 (py)} 2 (μ-Br) 2 Cu 2 Br 2 ] ( C5 ). In four of these complexes, severe disorders between pyrazolyl and pyridinyl donor groups are observed such that bis(pyrazolyl) and (pyrazolyl)(pyridinyl) coordination modes are concomitantly found. The donor competition is dissected by DFT calculation of the energy differences between the two coordination modes and NBO analysis of the donor situation. The pyrazolyl units provide with more donor strength although pyridine is considerably more basic.

Description: Metal ions poisoning can result from environmental factors, intentional action, or disruption of homeostasis. Although the origin of toxicity may be different, the treatment is similar. Chelation therapy aims to remove the excess of metal ions from tissues to stop further damage of cells. For almost every metal ion, molecules that are able to bind it and remove from the human body are known. Over the years some new chelating agents were discovered and introduced into clinical treatment. In this paper we have focused on typical chelators for metal ions, both essential and toxic for humans. The treatment of poisoning caused by essential metal ions is hard due to the risk of removing them from the biologically relevant molecules (e.g. enzymes). Acute metal ions poisoning is rather rare, so the development of chelators for such cases are historical, but prolonged toxicity of, especially, essential metal ions is extensively studied.

Description: The reactions of [Os(NO)Cl 5 ] 2– with glycine (GlyH), picolinic acid (PicoH), L -proline ( L -ProH) and D -proline ( D -ProH) afforded four novel complexes of the general formula [Os(NO)Cl 3 (AA)] – , where AA = Gly, Pico, L -Pro and D -Pro, respectively. X-ray diffraction studies have revealed that in all cases the same isomer type from three theoretically possible, has been isolated, namely mer (Cl), trans (NO, O)-[Os(NO)Cl 3 (AA)] – . Spectroscopic and electrochemical properties, behavior in aqueous solution and antiproliferative activity in three human cancer cell lines are also reported.

Description: The electron distributions in position and in momentum space of the hcp metals magnesium and zinc are investigated experimentally and compared to results of quantum-chemical calculations. Furthermore, a survey is given on recent analyses of the bonding properties of zinc and cadmium, using the method of increments. The experimental deformation densities were obtained by refining multipole models to X-ray diffraction data sets measured at 100 K with either Mo- K α (Mg) or Ag- K α (Zn) radiation. The final R F values (Valray/Jana2006) are 0.0028/0.0034 (Mg) and 0.0068/0.0068 (Zn). The differences to deformation densities obtained from periodic density functional calculations are discussed. The effect of dynamical electron correlation on the electron density was analyzed, using cluster models. Compton profiles were measured with 88.67 keV synchrotron radiation at beamline ID15B at the ESRF in Grenoble. Varied orientations of the samples allowed for probing the projected momentum distribution along the [100], [423] and [001] directions. Fourier transforms of the computed reciprocal form factor B ( r ) resulted in the corresponding theoretical Compton profiles. It is suggested that the anomalous hcp structure of zinc is favored by a kinetic balancing of the valence electrons, i.e. correlation mediated 4 s -3 d interactions.

Description: . This Research Report provides an overview on synthesis, structure, and reactivity of the recently discovered carboranylamidinate ligands. Carboranylamidinate anions of the type [( o -C 2 B 10 H 10 C(NHR)(=N R )] – ( R = i Pr, cyclohexyl) are readily accessible via addition of o -lithiocarborane to N , N ′-carbodiimides R –N=C=N– R . They combine the highly versatile characteristics of both amidinates and carboranes in one unique ligand system. Unlike simple amidinate anions, the carboranylamidinates coordinate to metal ions not as typical N , N ′-chelating ligands but adopt an unexpected κ 2 C, N -bonding mode. The free imine functionality in carboranylamidinates can be further deprotonated. The resulting dianions were demonstrated to be excellent starting materials for novel boron-rich heterocycles incorporating e.g. Si, Sn, P, or transition metals such as Ti, Zr, Rh, and Ir. Further modification of the carboranylamidinate cage structure includes the introduction of additional functional groups like –SH or –SeH as well as the selective removal of a boron atom with formation of novel nido -type dicarbollylamidinate ligands. An initial study already showed that transition metal carboranylamidinates are potentially useful as polymerization catalysts.

Description: KSbWO 6 was prepared by sol-gel method. N-doped KSbWO 6 (KSbWO 6– x N x ) was obtained by heating KSbWO 6 and urea at 400 °C. Both the compounds are characterized by powder X-ray diffraction (XRD), TEM, SEM-EDS, X-ray photo electronic spectroscopy (XPS), and UV/Vis diffuse reflectance spectroscopy (UV-DRS). A shift in the peak positions of powder XRD and XPS spectra was observed. The band gap energy ( E g ) of KSbWO 6 and N-doped KSbWO 6 was obtained from their diffused reflectance spectra. E g was reduced from 3.17 eV to 2.56 eV upon nitrogen doping in KSbWO 6 . The reduction of the E g is attributed to the lifting of valence band of N-doped KSbWO 6 , due to the mixing of O 2p states with N 2p states. The photocatalytic activity of both the samples was studied by degradation of methylene blue (MB). The nitrogen doped KSbWO 6 shows higher photocatalytic activity compared to that of KSbWO 6 .

Description: ABSTRACT [1]  Analysis of Lake Bonneville shorelines using LIDAR digital elevation data challenges accepted models of Wasatch fault deformation since the late Pleistocene. While footwall deformation of the Weber segment of the Wasatch fault is consistent with back-rotation of the footwall block and greatest displacement rate towards the center of the segment, shorelines along the footwall of the Salt Lake City segment decrease in elevation towards the interior and are highest at the segment boundaries, an opposite pattern of footwall deformation than predicted for boundaries arresting or strongly inhibiting displacement during earthquakes. The spatial pattern of footwall rebound implies that some of the proposed persistent fault segment boundaries do not stop earthquake ruptures that originate on adjacent fault segments, nor constrain ruptures initiated within the Salt Lake City segment. Net vertical fault displacement at the boundary between the Salt Lake and Provo segments is 16—20 m over the past 16.3—18.5 ka, corresponding to a vertical displacement rate of 0.8—1.2 mm/yr, a net fault slip rate of 2.0—2.8 mm/yr and horizontal extension rate of 1.8—2.6 mm/yr on the 25 o west-southwest dipping fault that forms the southern Salt Lake City segment boundary. Shoreline analysis suggests isostatic rebound caused by a drop in lake level was concentrated during a relatively short (~2000 yr) time period following the Bonneville flood at ~16 ka. LIDAR-derived topography in conjunction with robust geomorphic datums improves our ability to map deformation associated with lithospheric flexure and faulting while demonstrating the limitation of lacustrine shorelines in this type of analysis.

Description: [1]  We use recent results on statistical analysis of seismicity to present a robust method for comprehensive detection and analysis of earthquake clusters. The method is based on nearest-neighbor distances of events in space-time-energy domain. The method is applied to a 1981–2011 relocated seismicity catalog of southern California having 111,981 events with magnitudes m  ≥ 2, and corresponding synthetic catalogs produced by the Epidemic Type Aftershock Sequence (ETAS) model. Analysis of the ETAS model demonstrates that the cluster detection results are accurate and stable with respect to (i) three numerical parameters of the method, (ii) variations of the minimal reported magnitude, (iii) catalog incompleteness, and (iv) location errors. Application of the method to the observed catalog separates the 111,981 examined earthquakes into 41,393 statistically significant clusters comprised of foreshocks , mainshocks and aftershocks . The results reproduce the essential known statistical properties of earthquake clusters, which provide overall support for the proposed technique. In addition, systematic analysis with our method allows us to detect several new features of seismicity that include (i) existence of a significant population of single-event clusters ; (ii) existence of foreshock activity in natural seismicity that exceeds expectation based on the ETAS model; and (iii) dependence of all cluster properties, except area, on the magnitude difference of events from mainshocks but not on their absolute values. The classification of detected clusters into several major types, generally corresponding to singles, burst-like and swarm-like sequences, and correlations between different cluster types and geographic locations is addressed in a companion paper.

Description: [1]  For the first time, we report the amplitude variation with angle (AVA) pattern of bottom simulating reflectors (BSRs) beneath fracture-filled gas hydrate deposits when the effective medium is anisotropic. The common depth point (CDP) gathers of two mutually perpendicular multi-channel seismic profiles, located in the vicinity of Site NGHP-01-10, are appropriately processed such that they are fit for AVA analysis. AVA analysis of the BSR shows normal-incidence reflection coefficients of -0.04 to -0.11 with positive gradients of 0.04 to 0.31 indicating class IV pattern. The acoustic properties from isotropic rock physics model predict class III AVA pattern which cannot explain the observed class IV AVA pattern in Krishna-Godavari basin due to the anisotropic nature of fracture-filled gas hydrate deposits. [2]  We modeled the observed class IV AVA of the BSR by assuming that the gas hydrate bearing sediment can be represented by horizontally transversely isotropic (HTI) medium after accounting for anisotropic wave propagation effects on BSR amplitudes. The effective medium properties are estimated using Backus averaging technique and the AVA pattern of BSRs is modeled using the properties of overlying HTI and underlying isotropy/HTI media with or without free gas. Anisotropic AVA analysis of the BSR from the inline seismic profile shows 5–30 % gas hydrate concentration (equivalent to fracture density) and the azimuth of fracture system (fracture orientation) with respect to the seismic profile is close to 45°. Free gas below the base of gas hydrate stability zone is interpreted in the vicinity of fault system (F1).

Description: The chemistry of cytotoxic platinum(II) complexes is more or less restricted to ligand exchange reactions, derivatization of coordinated ligands is cumbersome, and subsequent purification in many cases impossible. Consequently, kinetically more inert platinum(IV) complexes found their way into the development of novel, promising anticancer drugs. Research has focused more and more during the last years on the use of platinum(IV) complexes featuring one or two axial succinato ligands in which one carboxylic acid moiety is available for further derivatization. In order to gain a deeper insight into the mechanism of action, isotopically labeled platinum(IV) complexes with axial (1,4– 13 C 2 )succinato ligands were synthesized and fully characterized by multinuclear ( 1 H, 13 C, 15 N, and 195 Pt) 1D- and 2D-NMR spectroscopy. Especially of note in this context is a long range 1 H, 13 C shift correlation signal detected between the equatorial ammine protons and the axially coordinated carboxylato moiety. Furthermore, their behavior in extracts of SW480 cancer cells was investigated. Preliminary results demonstrate that cisplatin analogs are reduced significantly faster in comparison to carboplatin analogs.

Description: The Cu II solution chemistry of synthetic derivatives of naturally occurring pseudo-octapeptides (patellamides and ascidiacyclamide) is described. The complex stabilities [mono- and dicopper(II) complexes] of five different ligands were determined by isothermal microcalorimetry (ITC), and square wave voltammetry (SQW) was used to elucidate the electrochemical properties. In agreement with published spectroscopic data, there is cooperative binding of two Cu II ions and the overall stabilities are, in agreement with known stabilities of the natural ligands and expectations based on the donor sets (two N-based heterocycles and one amide per Cu II ), only moderate ( K ≤ 10 6 ). There is a slight dependence of the stabilities on the ligand structure (configuration of the side chains), and that derived from the natural products forms the most stable complexes. Due to the complex equilibria in solution and the instability of the reduced forms, voltammetry shows complex equilibria, which preclude the full assignment of all processes. The positive reduction potentials are in agreement with relatively low complex stabilities. These observations complete earlier studies, concentrating on spectroscopy and structural aspects, and are also discussed in relation to the possible biological function of the cyclic peptides, i.e. metal ion transport, oxygen activation, carboanhydrase, and phosphatase activities.

Description: Setting out from protected L -cysteine a 2,5-diketopiperazine V can be synthesized, the reduction of which with NaBH 4 /TiCl 4 leads to (6 R ,8 aR )-7-methyl-6-(sulfanylmethyl)-thiazolidine [3,4- a ] piperazine, L 1 H as well as N , N ′-dimethyl-(2 R ,5 R )-bis(sulfanylmethyl) piperazine, L 2 H 2 , which were separated and characterized. L 2 H 2 can be obtained selectively, if V is reduced by NaBH 4 /TiCl 4 in the presence of DIEA · HCl, and it represents a precursor for a novel, chiral ligand, as after deprotonation it provides two thiolato and two amino donor functions for the coordination of a metal atom. Deprotonation of L 1 H and L 2 H 2 with NaOMe followed by treatment with NiBr 2 (dme) led to the isolation of the dimeric complexes [L 1 NiBr] 2 ( 1 ) and [L 2 Ni] 2 ( 2 ), respectively. Both were fully characterized, and cyclic voltammetry indicated the possibility of Ni II → Ni III oxidations for complex 2 . 2 can be regarded as a structural model for the A clusters of the acetyl coenzyme A synthase.

Description: [1]  Sequestration of large amounts of CO 2 within deep underground reservoirs has been proposed as a potential approach for reducing atmospheric emissions of greenhouse gases. A CO 2 sequestration project should address the associated environmental and safety issues and, in this respect, the importance of geomechanics has recently been widely recognized. Geomechanics is even more important when fluid injection is planned in faulted reservoirs. How much CO 2 can be safely injected into multi-compartment reservoirs? Are geomechanical constraints more restrictive than flow-dynamic constraints? These and other questions are addressed in the present study using a three-dimensional Finite Element - Interface Element geomechanical model. We simulate the possible mechanical failure in both the injected formation and the caprock, the fault/thrust reactivation, and the ground surface displacement in a faulted reservoir of the off-shore northern Italy, where seismic surveys provided an accurate characterization of the faulted geological structure. Based on reliable petrophysical/geomechanical properties from well-logs and pore overpressure as predicted by a fluid-dynamic model, the results show that the injection of 1 × 10 6  ton/a of CO 2 may be performed over a few years only. Thereafter part of the injected formation fails by shear stress. A number of parametric scenarios are investigated to address the major uncertainties on the geomechanical response to CO 2 injection. The modeling outcome suggests that shear failure and faults/thrusts reactivation can occur much before attaining the hydraulic fracturing pressure, hence representing two major constraints for a safe and permanent containment.

Description: [1]  We present numerical subduction models to investigate overriding plate deformation at subduction zones. All models show forearc shortening, resulting predominantly from shear stresses at the subduction zone interface and opposite-sense mantle shear stresses at the base of the forearc lithosphere. Models dominated by backarc extension show that it results from trench-normal positive velocity gradients in the mantle below the overriding plate. Such gradients result from toroidal mantle flow induced by slab rollback, with velocities below the leading part of the backarc faster than the overriding plate velocity. The velocity gradients induce basal shear stresses that increase trenchward and cause trenchward overriding plate motion at a velocity ( v OP⊥ ) whose spatial average is below the trench retreat velocity ( v T⊥ ). The combination of basal shear stresses and average v OP⊥ 〈 v T⊥ causes trench-normal deviatoric tension in the backarc and backarc extension. Models dominated by backarc shortening show that it results from a relatively immobile subduction hinge and trenchward overriding plate motion driven by poloidal mantle flow. The poloidal mantle flow is induced by downdip slab sinking and causes the average v OP⊥ 〉 v T⊥ . This results in trench-normal deviatoric compression and shortening in the leading part of the overriding plate as it collides with the subduction hinge. Ultimately, the geodynamic models demonstrate that backarc extension is favored for narrow slabs and near lateral slab edges, and is driven by rollback induced toroidal mantle flow, while backarc shortening is favored for the center of wide slabs, and is driven by poloidal mantle flow resulting from downdip slab motion.

Description: [1]  The Gamburtsev Subglacial Mountains (GSM), located near the center of East Antarctica, remain one of the most enigmatic mountain ranges on earth. A lack of direct geologic samples renders theirtectonic history almost totally unconstrained. We utilize teleseismic Rayleigh wave data from a two-year deployment of broadband seismic stations across the region to image shear velocity structure and analyze the lithospheric age of the GSM and surrounding regions. We solve for 2-D phase velocitiesand invert these results for 3-D shear velocity structure. We perform a Monte Carlo simulation to improve constraints of crustal thickness and shear velocity structure.Beneath the core of the GSM, we find crustal thickness in excess of 55 km.Mantle shear velocities remain faster than global average models to a depth of approximately 250 km, indicating a thick lithospheric root. Thinner crust and slower upper mantle velocities are observed beneath the Lambert Rift System and the Polar Subglacial Basin.When compared with phase velocity curves corresponding to specific tectonothermal ages elsewhere in the world, average phase velocity results for the GSM are consistent with regions of Archean – Paleoproterozoic origin. Combined with radiometric ages of detrital zircons found offshore, these results indicate a region of old crust that has undergone repeated periods of uplift and erosion, most recently during the Mesozoic breakup of Gondwana. Lower crustal seismic velocities imply a moderately dense lower crust beneath the core of the GSM, but with lower density than suggested by recent gravity models.

Description: [1]  This is a second paper in a study of statistical identification and classification of earthquake clusters using a relocated catalog of 1981–2011 seismicity in southern California and synthetic catalogs produced by the ETAS model. Here we focus on classification of event families – statistically significant clusters comprised of foreshocks , mainshocks and aftershocks – that are detected with the methodology discussed in part I of the study. The families are analyzed using their representation as time oriented tree graphs. The results (i) demonstrate that the clustering associated with the largest earthquakes, m  〉 7, is statistically different from that of small-to-medium earthquakes; (ii) establish the existence of two dominant types of small-to-medium magnitude earthquake families– burst-like and swarm-like sequences – and a variety of intermediate cluster forms obtained as a mixture of the two dominant types; (iii) suggest a simple new quantitative measure for identifying the cluster type based on its topological structure; (iv) demonstrate systematic spatial variability of the cluster characteristics on a scale of tens of kilometers in relation to heat flow and other properties governing the effective viscosity of a region; and (v) establish correlation between the family topological structure and a dozen of metric properties traditionally considered in the literature (number of aftershocks, duration, spatial properties, b -value, parameters of Omori-Utsu and Båth law, etc .). The burst-like clusters likely reflect highly-brittle failures in relatively cold regions, while the swarm-like clusters are likely associated with mixed brittle-ductile failures in regions with relatively high temperature and/or fluid content. The results of this and paper I may be used to develop improved region-specific hazard estimates and earthquake forecasts.

Description: A new chiral racemic ligand ( o -carboranyl)bis(2-hydroxymethyl)pyridine oCB(hmpH) 2 , that is composed of a central o -carborane unit where two arms radiate out of the cluster carbons each one containing a 2-pyridylmethylalcohol chelating arms, provides two potentially bidentate {NO} or one tetradentate {N 2 O 2 } binding pockets. An unprecedented octahedral Co II complex [CoCl 2 ( anti - oCB (hmpH) 2 ] was obtained under aerobic conditions and characterized by X-ray crystallography as well as IR and NMR spectroscopy. anti - oCB (hmpH) 2 acts as a tetradentate N 2 O 2 -ligand affording the complex as a racemic mixture of cis- α Δ-[CoCl 2 ( RR anti - oCB (hmpH) 2 )] and Λ-[CoCl 2 ( SS anti - oCB (hmpH) 2 )]. The new ligand oCB(hmpH) 2 appears to be suitable for producing a variety of new chiral-at-metal complexes.

Description: Abstract. The title compounds NH 4 [Cu(S 2 CNH 2 ) 2 ] · H 2 O (A) and CuS 2 CNH 2 (B) were prepared from aqueous alcoholic solutions by reaction of ammoniumdithiocarbamate with copper sulfate in presence of excess cyanide as reductive. (A) crystallizes in the orthorhombic space group C 222 1 (No. 20) with a = 8.9518(6), b = 9.6414(6) and c = 10.6176(8) Å, Z = 4. (B) crystallizes in the orthorhombic space group P 2 1 2 1 2 1 (No. 19) with a = 5.9533(4), b = 6.6276(4) and c = 9.4834(5) Å, Z = 4. In the crystal structure of (A) copper has a tetrahedral surrounding of four monodentate dithiocarbamate ligands. These structural units form 2D nets stacked along [001]. Staggered chains consisting of H 2 O and NH 4 + penetrate the crystal structure along [001] yielding additional coherence via hydrogen bonds. The crystal structure of (B) comprises a three-dimensional tetrahedral framework of CuS 4 units exclusively linked by vertices. The arrangement is reminiscent of a filled β -cristobalite structure with the dithiocarbamate ligands extending into the hollow spaces. Thermal decomposition precedes stepwise finally giving Cu 2 S in each case.

Description: A thorough study on the thermoelectric potential of the layered compound SnBi 2 Te 4 is presented. Phase range studies on SnBi 2 Te 4 , unit cell parameters by powder X-ray diffraction, and electronic structure calculations (both LDA and GGA functional) were performed. Physical property measurements regarding substitution of tin and bismuth with the triel ( Tr = Ga, In, Tl) elements are presented towards the improvement of thermoelectric properties, according to Tr x Sn 1– x Bi 2 Te 4 and Tr x SnBi 2– x Te 4 . The range of inclusion was generally over 0.01 ≤ x ≤ 0.15 to monitor compound changes as well as phase purity limits. Seebeck coefficient, S , electrical conductivity, σ , and thermal conductivity, κ , were measured, yielding the dimensionless Figure of merit, ZT , data over a temperature range between 300 K and 680 K. Results of partial replacements of tin and bismuth are compared and reported. ZT max values range from 0.10 to 0.34 depending on the dopant, achieved at temperatures from 355 K to 420 K.

Description: A new two-step procedure for the synthesis of MoS 2 nanotubes using lead as a growth promoter is reported. In the first step, molybdenum suboxide nanowhiskers containing a small amount of lead atoms were created by exposing a pressed MoS 2 +Pb mixture to highly compressed shock-heated argon gas, with estimated temperatures exceeding 9900 K. In the second step, these molybdenum suboxide nanowhiskers served as templates for the sulfidization of the oxide into MoS 2 nanotubes (by using H 2 S gas in a reducing atmosphere at 820 °C). Unlike the case of WS 2 nanotubes, the synthesis of a pure phase of MoS 2 nanotubes from molybdenum oxide has proven challenging, due mostly to the volatile nature of the latter at the high requisite reaction temperatures (〉800 °C). In contrast, the nature and apparent reaction mechanism of the method reported herein are amenable to future scale-up. The high-temperature shockwave system should also facilitate the synthesis of new nanostructures from other layered materials.

Description: The reaction of RuCl 2 (PPh 3 ) 3 with N -pyrazolylpropanamide ( N -ppa) displaces a single PPh 3 producing the six-coordinate complex RuCl 2 (PPh 3 ) 2 ( N -ppa) ( 1 ). A crystal structure determination of the dichloromethane solvate RuCl 2 (PPh 3 ) 2 ( N -ppa) · 2CH 2 Cl 2 ( 1·2CH 2 Cl 2 ) revealed that the geometry about the central Ru atom is distorted octahedral with the chloride ligands in trans -position and the N -ppa acting as N , O -chelating ligand. In the solid state, RuCl 2 (PPh 3 ) 2 ( N -ppa) molecules are dimerized via N–H ··· Cl hydrogen bonds. The dimers pack as chains in the c direction and form voids that are occupied by dichloromethane solvent molecules.

Description: Four complexes with supramolecular architectures, namely, MZCA · 3H 2 O ( 1 ), [Zn(H 2 O) 6 ] 2+ · [MZCA] 2 · [H 2 O] 6 ( 2 ), [Mn(MZCA) 2 (H 2 O) 4 ] · 2H 2 O ( 3 ), and [Ni(MZCA) 2 (H 2 O) 4 ] · 2H 2 O ( 4 ) [MZCA = 3-(carboxymethyl)-2, 7-dimethyl-3H-benzo[d]imidazole-5-carboxylic acid], were synthesized and characterized by elemental analysis, IR spectroscopy, and single-crystal X-ray diffraction. Complexes 1 and 2 display a remarkable 3D network with 1D hydrophilic channels. Complexes 3 and 4 are isostructural and exhibit a 3D structure encapsulating 1D 24-membered ring microporous channels. The UV/Vis and fluorescent spectra were measured to characterize complexes 1 – 4 . The thermal stability of complexes 2 – 4 were also examined.

Description: The transition metal dihydrogen hypodiphosphate hydrates K 2 [Co(H 2 P 2 O 6 ) 2 (H 2 O) 2 ] · H 2 O ( 1 ), K 2 [Ni(H 2 P 2 O 6 ) 2 (H 2 O) 2 ] · H 2 O ( 2 ), K 2 [Cu(H 2 P 2 O 6 ) 2 (H 2 O) 2 ] · H 2 O ( 3 ) and K 2 [Zn(H 2 P 2 O 6 ) 2 (H 2 O) 2 ] · H 2 O ( 4 ) were synthesized and characterized by single crystal structure determination. The compounds 1 – 4 crystallize isotypic in the monoclinic space group C 2/ m (no. 12) with two formula units in the unit cell. The crystal structure is built up by [H 2 P 2 O 6 ] 2– units in an eclipsed conformation, by the corresponding transition metal, potassium cations, and water molecules. The eclipsed conformation of the [H 2 P 2 O 6 ] 2– has not been previously observed in none of known hypodiphosphates(IV) analyzed via X-ray diffraction. However, its proposed based on spectroscopic methods. FT-IR/FIR and FT-Raman spectra of the crystalline salts were recorded and the thermal behavior of the compounds was investigated.

Description: Two coordination polymers, [Co 2 (Hcpip) 2 (phth)] n · 3 n (H 2 O) ( 1 ) and [Mn 2 (Hcpip) 2 (phth)] n ( 2 ), {H 2 cpip = 2-(2-carboxyphenyl)imidazo[4,5-f](1,10)- phenanthroline, H 2 phth = phthalic acid}, were hydrothermally synthesized and characterized by elemental analysis, IR spectroscopy, and single-crystal X-ray diffraction. Complex 1 is a 1D chain, in which the dinuclear [Co 2 (Hcpip) 2 ] 2+ units are linked through (phth) 2– anions. Complex 2 is a 2D layer structure, which is constructed from the 1D chains bridged by (phth) 2– anions. The magnetic properties of 1 and 2 show that the weak ferromagnetic interactions occurred between Co II ions in 1 and a weak antiferromagnetic interactions exist between Mn II ions in 2 . These two complexes have good thermal stabilities.

Description: Three tungsten oxychloride clusters containing the nearly D 3 d symmetric [(W 6 O 6 i Cl 6 i )Cl 6 a ] n – ( n = 2, 3) core were prepared from the cluster acid (H 5 O 2 ) 2 [W 6 O 6 Cl 12 ] · 4H 2 O and structurally characterized by single-crystal X-ray diffraction. The copper compound [Cu(H 2 O) 4 ][W 6 O 6 Cl 12 ] · 12H 2 O releases water molecules to yield [Cu(H 2 O) 6 ][W 6 O 6 Cl 12 ]. Both compounds are represented as diamagnetic clusters, having 14 electrons in W–W bonding states. Magnetic measurements on the calcium compound [Ca(H 2 O) 7 ] 2 [W 6 O 6 Cl 12 ]Cl revealed a paramagnetic cluster having 15 valence electrons.