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SUMMARY The Global Positioning System (GPS), although it has existed for only 30 years, is an important source for active tectonics, resulting in estimates of plate motions very close to geologic estimates over millions of years. GPS is also used for elastic block models to calculate slip rates for a better understanding of Earth’s active crustal deformation. GPS-derived velocity fields may be used as the basis for clustering analysis to create a preliminary definition of block geometry. In this study, we used published horizontal velocity fields to evaluate the effects of data dependences on determining the optimum number of clusters with algorithms. For this purpose, we used different variations of velocity fields in Turkey and tested four different algorithms that are Davies–Bouldin index, the elbow method, GAP statistics algorithm and the silhouette method. We also clustered velocity components with the k-means technique and compared the results with previous studies.

SUMMARYIn order to better assess earthquake hazards, it is vital to have a better understanding of the spatial and temporal characteristics of fault creep that occur on ruptured faults during the period following major earthquakes. Towards this end, we use new far-field GPS velocities from continuous stations (extending ∼50–70 km from the fault) and updated near-fault GPS survey observations, with high temporal and spatial density, to constrain active deformation along the Mw7.4, 1999 Izmit, Turkey Earthquake fault. We interpret and model deformation as resulting from post-seismic afterslip on the coseismic fault. In the broadest sense, our results demonstrate that logarithmically decaying post-seismic afterslip continues at a significant level 20 yr following 1999 Earthquake. Elastic models indicate substantially shallower apparent locking depths at present than prior to the 1999 Earthquake, consistent with continuing afterslip on the coseismic fault at depth. High-density, near-fault GPS observations indicate shallow creep on the upper 1–2 km of the coseismic fault, with variable rates, the highest and most clearly defined of which reach ∼12 mm yr−1 (10–15 mm yr−1, 95 per cent c.i.) near the epicentre between 2014–2016. This amounts to ∼half the long-term slip deficit rate.

Individual tennis points evolve over time and space, as each of the two opposing players are constantly reacting and positioning themselves in response to strikes of the ball. However, these reactions are diminished into simple tally statistics such as the amount of winners or unforced errors a player has. In this paper, a new way is proposed to evaluate how an individual tennis point is evolving, by measuring how many points a player can expect from each shot, given who struck the shot and where both players are located. This measurement, named “Expected Shot Value” (ESV), derives from stochastically modeling each shot of individual tennis points. The modeling will take place on multiple resolutions, differentiating between the continuous player movement and discrete events such as strikes occurring and duration of shots ending. Multi-resolution stochastic modeling allows for the incorporation of information-rich spatiotemporal player-tracking data, while allowing for computational tractability on large amounts of data. In addition to estimating ESV, this methodology will be able to identify the strengths and weaknesses of specific players, which will have the ability to guide a player’s in-match strategy.

SUMMARY The present-day tectonics of the southern Red Sea region is complicated by the presence of the overlapping Afar and southern Red Sea rifts as well as the uncertain kinematics and extent of the Danakil block in between. Here we combine up to 16 yr of GPS observations and show that the coherent rotation of the Danakil block is well described by a Danakil-Nubia Euler pole at 16.36°N, 39.96°E with a rotation rate of 2.83 deg Myr–1. The kinematic block modeling also indicates that the Danakil block is significantly smaller than previously suggested, extending only to Hanish-Zukur Islands (∼13.8°N) with the area to the south of the islands being a part of the Arabian Plate. In addition, the GPS velocity field reveals a wide inter-rifting deformation zone across the northern Danakil-Afar rift with ∼5.6 mm yr–1 of east–west opening across Gulf of Zula in Eritrea. Together the results redefine some of the plate boundaries in the region and show how the extension in the southern Red Sea gradually moves over to the Danakil-Afar rift.

Southern Africa is typically considered to belong to a single tectonic plate, Nubia, despite active faulting along the southwestern branch of the East African Rift System. We analyze regional Global Navigation Satellite System (GNSS) measurements, and find that the “San” microplate, situated south of the southwestern branch of the East African Rift, is statistically distinct from Nubia, with 0.4–0.7 mm/yr of extension across the boundary. Adding nine new campaign GNSS sites, we show that the extension rate across the southern Malawi Rift is 2.2 ± 0.3 mm/yr, with 75% of the relative velocity occurring over 890 km, despite the surface expression of faulting being

Author(s): Floyd, Michael; Funning, Gareth; Fialko, Yuri; Terry, Rachel; Herring, Thomas | Abstract: Abstract The Mwn6.4 and Mwn7.1 Ridgecrest, California, earthquakes of July 2019 occurred within 34nhr of each other on conjugate strike-slip faults in the Mojave Desert, just north of the central Garlock fault. Here, we present the results of a survey of 18 Global Navigation Satellite Systems (GNSS) sites conducted in the immediate aftermath of the earthquakes, including five sites that recorded the motion of the second earthquake after having been set up immediately following the first, as well as processed results from continuous GNSS sites throughout the region. Our field work in response to the earthquakes provides additional constraints on the ground displacement due to both earthquakes, complementing data from a spatially sparser network of continuously recording GNSS sites in the area, as well as temporally sparser Interferometric Synthetic Aperture Radar data that were able to capture a combined deformation signal from the two earthquakes.

Author(s): Konca, A Ozgun; Guvercin, Sezim Ezgi; Ozarpaci, Seda; Ozdemir, Alpay; Funning, Gareth J; Dogan, Ugur; Ergintav, Semih; Floyd, Michael; Karabulut, Hayrullah; Reilinger, Robert | Abstract: SUMMARY The 2017 July 20, Mw6.6 Bodrum–Kos earthquake occurred in the Gulf of Gokova in the SE Aegean, a region characterized by N–S extension in the backarc of the easternmost Hellenic Trench. The dip direction of the fault that ruptured during the earthquake has been a matter of controversy where both north- and south-dipping fault planes were used to model the coseismic slip in previous studies. Here, we use seismic (seismicity, main shock modelling, aftershock relocations and aftershock mechanisms using regional body and surface waves), geodetic (GPS, InSAR) and structural observations to estimate the location, and the dip direction of the fault that ruptured during the 2017 earthquake, and the relationship of this event to regional tectonics. We consider both dip directions and systematically search for the best-fitting locations for the north- and south-dipping fault planes. Comparing the best-fitting planes for both dip directions in terms of their misfit to the geodetic data, proximity to the hypocenter location and Coulomb stress changes at the aftershock locations, we conclude that the 2017 earthquake ruptured a north-dipping fault. We find that the earthquake occurred on a 20–25 km long, ∼E–W striking, 40° north-dipping, pure normal fault with slip primarily confined between 3 and 15 km depth, and the largest slip exceeding 2 m between depths of 4 and 10 km. The coseismic fault, not mapped previously, projects to the surface within the western Gulf, and partly serves both to widen the Gulf and separate Kos Island from the Bodrum Peninsula of SW Anatolia. The coseismic fault may be an extension of a mapped, north-dipping normal fault along the south side of the Gulf of Gokova. While all of the larger aftershocks are consistent with N–S extension, their spatially dispersed pattern attests to the high degree of crustal fracturing within the basin, due to rapid trenchward extension and anticlockwise rotation within the southeastern Aegean.

Glioblastoma (GBM) is the most common type of primary brain tumor in adults, with a 5-year overall survival of only 7%. Oncolytic viruses are a promising and active area of research in GBM with the recent approval of an oncolytic HSV-1 vector, teserpaturev (Delytact, also known as G47Δ, Daiichi Sankyo) for recurrent GBM based on an overall survival of 92% at 1 year. G207, an HSV-1 vector more attenuated than teserpaturev, recently reported acceptable tolerability with evidence of responses in children with recurrent or progressive high-grade glioma. These vectors are not expressing any cDNA transgene that may enhance and prolong antitumor activity. We report here the development of ONCR-GBM, an oncolytic HSV-1 vector specifically engineered for safety using a microRNA attenuation strategy to limit viral replication in healthy cell type of the CNS. ONCR-GBM has been developed from a novel potently oncolytic strain of HSV-1 and optimized for infection of GBM tumor cells. Antitumor efficacy has been further enhanced through the expression of multiple payloads designed to modify the immunosuppressive tumor microenvironment of GBM. We previously reported that a vector expressing IL-12 and a PD-1 antagonist nanobody achieved > 90% survival after a single injection in the GL261-Nectin1 orthotopic model. This vector promoted immune cell recruitment and activation in tumors and protected surviving animals from a subsequent tumor rechallenge. Additional payloads selected for interfering with the immune suppressive stroma in GBM have been evaluated for potentiating the response of IL-12 and anti PD-1 expressing HSV-1. We will present the outcome of the in vivo screen, and the selection of the optimal combination of payloads featured in ONCR-GBM clinical candidate.

Being a part of ongoing continental collision between the Arabian and Eurasian plates, the Caucasus region is a remarkable site of moderate to strong seismicity, where devastating earthquakes caused significant losses of lives and livelihood. In this article, we survey geology and geodynamics of the Caucasus and its surroundings; magmatism and heat flow; active tectonics and tectonic stresses caused by the collision and shortening; gravity and density models; and overview recent geodetic studies related to regional movements. The tectonic development of the Caucasus region in the Mesozoic-Cenozoic times as well as the underlying dynamics controlling its development are complicated processes. It is clear that the collision is responsible for a topographic uplift / inversion and for the formation of the fold-and-thrust belts of the Greater and Lesser Caucasus. Tectonic deformations in the region is influenced by the wedge-shaped rigid Arabian block indenting into the relatively mobile region and producing near N-S compressional stress and seismicity in the Caucasus. Regional seismicity is analysed with an attention to sub-crustal seismicity under the northern foothills of the Greater Caucasus, which origin is unclear – whether the seismicity associated with a descending oceanic crust or thinned continental crust. Recent seismic tomography studies are in favour of the detachment of a lithospheric root beneath the Lesser and Greater Caucasus. The knowledge of geodynamics, seismicity, and stress regime in the Caucasus region assists in an assessment of seismic hazard and risk. We look finally at existing gaps in the current knowledge and identify the problems, which may improve our understanding of the regional evolution, active tectonics, geodynamics, shallow and deeper seismicity, and surface manifestations of the lithosphere dynamics. Among the gaps are those related to uncertainties in regional geodynamic and tectonic evolution (e.g., continental collision and associated shortening and exhumation, lithosphere structure, deformation and strain-stress partitioning) and to the lack of comprehensive datasets (e.g., regional seismic catalogues, seismic, gravity and geodetic surveys).

A seismic gap along the western segment of the North Anatolian Fault, in the Marmara-Izmit region, was identified before the 1999 M7.6, Izmit and M7.4 Duzce earthquakes, so the region along the coseismic fault has been monitored with geodetic techniques for decades, providing well defined pre-, co- and post-seismic deformations. Here, we report new continuous and survey GPS measurements with near-fault (~2 – 10 km to the fault) and far-fault (~50 – 70 km from the fault) stations, including 7 years (2013 – 2019) of continuous observations, and 5 near-fault campaigns (every six months between 2014 – 2016) to further investigate postseismic deformation. GPS observations were processed with the GAMIT/GLOBK (v10.7) GNSS software. We used these observations to estimate the spatial distribution of current aseismic after-slip, along the 1999 Izmit rupture. We also searched for spatiotemporal changes of shallow creep events along the surface trace. With elastic models and GPS observations, we determined a shallow creep rate that reaches a maximum around the epicenter of the 1999 Izmit earthquake of about 12.7 ± 1.2 mm/yr, consistent with published InSAR results. Creep rates decrease both east and west of the epicentral region. Moreover, we show that broad-scale postseismic effects that diminish logarithmically, continue at present. (This study is supported by TUBITAK 1001 project no: 113Y102 and 117Y278)

Author(s): Xu, W; Wu, S; Materna, K; Nadeau, R; Floyd, M; Funning, G; Chaussard, E; Johnson, CW; Murray, JR; Ding, X; Burgmann, R | Abstract: The detailed spatial variations of strain accumulation and creep on major faults in the northern San Francisco Bay Area (North Bay), which are important for seismic potential and evaluation of natural hazards, remain poorly understood. Here we combine interferometric synthetic aperture radar data from the ERS-1/2 and Envisat satellites between 1992 and 2010 with continuous and campaign GPS data to obtain a high spatial and temporal coverage of ground deformation of the North Bay. The SAR data from both ascending and descending orbits are combined to separate horizontal and vertical components of the deformation. We jointly invert the horizontal component of the mean velocities derived from these data to infer the deep strike-slip rates on major locked faults. We use the estimated deep rates to simulate the long-wavelength deformation due to interseismic elastic strain accumulation along these locked faults. After removing the long-wavelength signal from the InSAR horizontal mean velocity field, we estimate fault-parallel surface creep rates of up to 2nmm/year along the central section of the Rodgers Creek fault and surface creep rates ranging between 2 and 4nmm/year along the Concord fault. No surface creep is geodetically resolved along the West Napa and Green Valley fault zones. We identified characteristically repeating earthquakes on the Rodgers Creek fault, the West Napa fault, the Green Valley fault, and the Concord fault. Nontectonic deformation in the Geysers geothermal field and in Late Cenozoic basins (Rohnert Park and Sonoma basins) are also observed, likely due to hydrological and sediment-compaction processes, respectively.

We identify a reduction reaction of boron oxide by Si during melt fluxing of the Fe-Co-Si-B-P system, which results in an unexpected and significant B enrichment and Si depletion in the alloy. Taking this reaction into account, an optimized Fe-Co-Si-B-P alloy free from oxide inclusions and demonstrating a global peak in glass forming ability is formed. Following a 22-h high temperature fluxing of the melt, alloy with composition Fe_(57.5)Co_(20.2)Si_(10.2)B_(2.1)P_(10) transforms to Fe_(57)Co_(19.2)Si_(6.8)B_(7.4)P_(9.6), and its critical rod diameter increases from 1 mm to 5 mm. The alloy also demonstrates excellent soft ferromagnetic performance characterized by a magnetic saturation of 1.53 T.

We present and interpret newly determined site motions derived from GPS observations made from 2008 through 2016 in the Republic of Georgia, which constrain the rate and locus of active shortening in the Lesser–Greater Caucasus continental collision zone. Observation sites are located along two ∼160 km-long profiles crossing the Lesser–Greater Caucasus boundary zone: one crossing the Rioni Basin in western Georgia and the other crossing further east near the longitude of Tbilisi. Convergence across the Rioni Basin Profile occurs along the southern margin of the Greater Caucasus, near the surface trace of the north-dipping Main Caucasus Thrust Fault (MCTF) system, and is consistent with strain accumulation on the fault that generated the 1991 MW6.9 Racha earthquake. In contrast, convergence along the Tbilisi Profile occurs near Tbilisi and the northern boundary of the Lesser Caucasus (near the south-dipping Lesser Caucasus Thrust Fault), approximately 50–70 km south of the MCTF, which is inactive within the resolution of geodetic observations ( ± 0.5 mm/yr ) at the location of the Tbilisi Profile. We suggest that the southward offset of convergence along strike of the range is related to the incipient collision of the Lesser–Greater Caucasus, and closing of the intervening Kura Basin, which is most advanced along this segment of the collision zone. The identification of active shortening near Tbilisi requires a reevaluation of seismic hazards in this area.

The 2019 Ridgecrest earthquakes pose interesting questions about the nature of intersecting conjugate ruptures, and also the possibility of re-rupture of fault segments. Aftershocks of the July 4th...

Forming of composite laminates is an effective manufacturing method that improves repeatability, enables tailoring of material orientations, and reduces time and cost when compared to more labour-intensive alternatives. However, this process is often prone to defects - leading to delays and ultimately scrapping of expensive parts - that are traditionally mitigated through resource intensive trial and error approaches. The risks of the forming process can be mitigated by using process simulation as a tool to develop a robust process window. In order to successfully model the forming of composite materials, the relevant deformation mechanisms and material attributes, shown in Figure 1, need to be considered. This paper presents a finite element simulation framework to predict the occurrence of defects in the forming and consolidation steps of the manufacturing process of fibre reinforced composites. The modelling approach presents a novel discretization strategy for each ply with a superposition of solid and shell elements. This solution uses a coupled pressure-displacement implicit analysis procedure that allows for the simulation of resin flow and is well suited to simulate autoclave consolidation and simple forming cases where through-thickness deformations are important. Simulation results show good agreement with experimental forming trials and other work found in literature in terms of deformation mechanisms and defects observed., 34th Technical Conference of the American Society for Composites, ASC 2019, September 23-25, 2019, Atlanta, USA

We present fast algorithms for estimating common parameters in geodetic time series based on statistical approaches to assess the impact of temporal correlations. One such assessment is based on the characteristics of the time series residuals averaged over different durations and with the statistical characteristics extrapolated with a first-order Gauss–Markov process to infinite averaging time. This approach circumvents a limitation of spectral methods, which cannot reliably account for the impact of temporal correlations over periods longer than the length of a given time series. The subsequent fast approach is the use of a Kalman filter with process noise values determined from the first-order Gauss–Markov characteristics to estimate all parameters. These methods are particularly useful for assessing long and numerous geodetic time series, which are nowadays ubiquitous, because they are much less computationally intensive than comprehensive methods, such as maximum likelihood estimators. Our approaches are compared to other commonly used programs, such as Hector, to understand the speed and impact of outliers on the algorithms, and to provide advice and suggestions on the uses of such algorithms in operational geodetic processing.

Following earthquakes, faults are often observed to continue slipping aseismically. It has been proposed that this afterslip occurs on parts of the fault with rate-strengthening friction that are stressed by the main shock, but our understanding has been limited by a lack of immediate, high-resolution observations. Here we show that the behavior of afterslip following the 2014 South Napa earthquake in California varied over distances of only a few kilometers. This variability cannot be explained by coseismic stress changes alone. We present daily positions from continuous and survey GPS sites that we remeasured within 12 h of the main shock and surface displacements from the new Sentinel-1 radar mission. This unique geodetic data set constrains the distribution and evolution of coseismic and postseismic fault slip with exceptional resolution in space and time. We suggest that the observed heterogeneity in behavior is caused by lithological controls on the frictional properties of the fault plane.

Author(s): Funning, Gareth J; Brooks, Benjamin; Fialko, Yuri; Floyd, Michael; Haase, Jennifer; Hammond, William; Sandwell, David T; Svarc, Jerry; Xu, Xiaohua

©2015. American Geophysical Union. All Rights Reserved. Campaign GPS data collected from 2002 to 2014 result in 41 new site velocities from the San Bernardino Mountains and vicinity. We combined these velocities with 93 continuous GPS velocities and 216 published velocities to obtain a velocity profile across the Pacific-North America plate boundary through the San Bernardino Mountains. We modeled the plate boundary-parallel, horizontal deformation with 5-14 parallel and one obliquely oriented screw dislocations within an elastic half-space. Our rate for the San Bernardino strand of the San Andreas Fault (6.5±3.6mm/yr) is consistent with recently published latest Quaternary rates at the 95% confidence level and is slower than our rate for the San Jacinto Fault (14.1±2.9mm/yr). Our modeled rate for all faults of the Eastern California Shear Zone (ECSZ) combined (15.7±2.9mm/yr) is faster than the summed latest Quaternary rates for these faults, even when an estimate of permanent, off-fault deformation is included. The rate discrepancy is concentrated on faults near the 1992 Landers and 1999 Hector Mine earthquakes; the geodetic and geologic rates agree within uncertainties for other faults within the ECSZ. Coupled with the observation that postearthquake deformation is faster than the pre-1992 deformation, this suggests that the ECSZ geodetic-geologic rate discrepancy is directly related to the timing and location of these earthquakes and is likely the result of viscoelastic deformation in the mantle that varies over the timescale of an earthquake cycle, rather than a redistribution of plate boundary slip at a timescale of multiple earthquake cycles or longer.

BACKGROUND: Human immunodeficiency virus (HIV)–infected individuals are at increased risk of age-associated functional impairment, even with effective antiretroviral therapy (ART). A concurrent characterization of skeletal muscle, physical function, and immune phenotype in aviremic middle-aged HIV-infected adults represents a knowledge gap in prognostic biomarker discovery. METHODS: We undertook a prospective observational study of 170 middle-aged, HIV-infected ambulatory men and women with CD4(+) T-cell counts of at least 350/µL and undetectable plasma viremia while on effective ART, and uninfected control participants. We measured biomarkers for inflammation and immune activation, fatigue, the Veterans Aging Cohort Study mortality index, and physical function. A subset also received a skeletal muscle biopsy and computed tomography scan. RESULTS: Compared to the uninfected participants, HIV-infected participants displayed increased immune activation (P < .001), inflammation (P = .001), and fatigue (P = .010), and in a regression model adjusting for age and sex displayed deficits in stair-climb power (P < .001), gait speed (P = .036), and predicted metabolic equivalents (P = .019). Skeletal muscle displayed reduced nuclear peroxisome proliferator-activated receptor-γ coactivator 1α–positive myonuclei (P = .006), and increased internalized myonuclei (P < .001) that correlated with immune activation (P = .003) and leukocyte infiltration (P < .001). Internalized myonuclei improved a model for HIV discrimination, increasing the C-statistic from 0.84 to 0.90. CONCLUSIONS: Asymptomatic HIV-infected middle-aged adults display atypical skeletal muscle profiles, subclinical deficits in physical function, and persistent inflammation and immune activation. Identifying biomarker profiles for muscle dysregulation and risk for future functional decline in the HIV-infected population will be key to developing and monitoring preventive interventions. CLINICAL TRIALS REGISTRATION: NCT03011957.

Author(s): Gonzalez-Ortega, A; Fialko, Y; Sandwell, D; Nava-Pichardo, FA; Fletcher, J; Gonzalez-Garcia, J; Lipovsky, B; Floyd, M; Funning, G | Abstract: El Mayor-Cucapah earthquake occurred on 4 April 2010 in northeastern Baja California just south of the U.S.-Mexico border. The earthquake ruptured several previously mapped faults, as well as some unidentified ones, including the Pescadores, Borrego, Paso Inferior and Paso Superior faults in the Sierra Cucapah, and the Indiviso fault in the Mexicali Valley and Colorado River Delta.We conducted several Global Positioning System (GPS) campaign surveys of preexisting and newly established benchmarks within 30 km of the earthquake rupture. Most of the benchmarks were occupied within days after the earthquake, allowing us to capture the very early postseismic transient motions. The GPS data show postseismic displacements in the same direction as the coseismic displacements; time series indicate a gradual decay in postseismic velocities with characteristic time scales of 66 ± 9 days and 20 ± 3 days, assuming exponential and logarithmic decay, respectively. We also analyzed interferometric synthetic aperture radar (InSAR) data from the Envisat and ALOS satellites. The main deformation features seen in the line-of-sight displacement maps indicate subsidence concentrated in the southern and northern parts of the main rupture, in particular at the Indiviso fault, at the Laguna Salada basin, and at the Paso Superior fault. We show that the near-field GPS and InSAR observations over a time period of 5 months after the earthquake can be explained by a combination of afterslip, fault zone contraction, and a possible minor contribution of poroelastic rebound. Far-field data require an additional mechanism, most likely viscoelastic relaxation in the ductile substrate. ©2014. American Geophysical Union.

We use survey and continuous GPS observations during the period 1997-2010 to investigate active deformation in the Isparta Angle region of SW Anatolia, Turkey. This region, bordered by the Fethiye Burdur Fault Zone (FBFZ) in the west and the SE extension of the Aksehir Simav Fault Zone (AKSFZ) in the east, accommodates a part of the active deformation of W Turkey. Our results show that the Isparta Angle region rotates counter-clockwise (CCW) with respect to Anatolia. Both the FBFZ and the AKSFZ are predominantly transtensional boundaries that accommodate southward motion of the Isparta region with respect to Anatolia. The FBFZ has left-lateral strike-slip behaviour along its SW segment that changes to right-lateral strike-slip along its NE extension. This change in the sense of strike-slip motion is accommodated by extension on a NW-SE striking normal fault system that is associated with the Menderes Graben system. Transtensional fault systems along the boundaries of the Isparta Angle with Anatolia are inconsistent with extrusion models for present-day southward motion. An increase in motion rates towards the Hellenic and Cyprus arc subduction systems, and CCW of the Isparta region, supports dynamic models involving active rollback of the subducting African Plate, toroidal mantle flow around the eastern edge of the subducting African slab near the Hellenic arc/Florence Rise junction, and/or gravitational collapse of the overriding Anatolia Plate.

Territory of Azerbaijan is located within the central part of the Mediterranean tectonic belt seismicity of which is caused by intensive geodynamic interaction of the Eurasian and Arabian lithospheric plates (Khain 2000).

Historical accounts describe an earthquake and tsunami on 21 July AD 365 that destroyed cities and drowned thousands of people in coastal regions from the Nile Delta to modern-day Dubrovnik. The location and tectonic setting of this earthquake have been uncertain until now. Here, we present evidence from radiocarbon data and field observations that western Crete was lifted above sea level, by up to 10 m, synchronously with the AD 365 earthquake. The distribution of uplift, combined with observations of present-day seismicity, suggest that this earthquake occurred not on the subduction interface beneath Crete, but on a fault dipping at about 30∘ within the overriding plate. Calculations of tsunami propagation show that the uplift of the sea floor associated with such an earthquake would have generated a damaging tsunami through much of the eastern Mediterranean. Measurement of the present rate of crustal shortening near Crete yields an estimate of ∼5,000 yr for the repeat time of tsunamigenic events on this single fault in western Crete, but if the same process takes place along the entire Hellenic subduction zone, such events may occur approximately once every 800 yr. In the year AD 365, an earthquake and tsunami destroyed much of the eastern Mediterranean coastal regions. The distribution of uplift at the time suggests that the earthquake occurred on a fault within the overriding plate at the subduction zone beneath Crete, and not on the subduction interface itself.

To gain insight into the large toughness variability observed between metallic glasses (MGs), we examine the origin of fracture toughness through bending experiments and molecular dynamics (MD) simulations for two binary MGs: Pd_(82)Si_(18) and Cu_(46)Zr_(54). The bending experiments show that Pd_(82)Si_(18) is considerably tougher than Cu_(46)Zr_(54), and the higher toughness of Pd_(82)Si_(18) is attributed to an ability to deform plastically in the absence of crack nucleation through cavitation. The MD simulations study the initial stages of cavitation in both materials and extract the critical factors controlling cavitation. We find that for the tougher Pd_(82)Si_(18), cavitation is governed by chemical inhomogeneity in addition to topological structures. In contrast, no such chemical correlations are observed in the more brittle Cu_(46)Zr_(54), where topological low coordination number polyhedra are still observed around the critical cavity. As such, chemical inhomogeneity leads to more difficult cavitation initiation in Pd_(82)Si_(18) than in Cu_(46)Zr_(54), leading to a higher toughness. The absence of chemical separation during cavitation initiation in Cu_(46)Zr_(54) decreases the energy barrier for a cavitation event, leading to lower toughness.

The potential for large, shallow earthquakes and their associated seismic hazard in the eastern Caucasus, an area of dense population and sensitive industrial infrastructure, remains speculative based on historical precedent and current geologic and seismologic observations. Here we present updated and expanded results from a GPS network between the northern edge of the Lesser Caucasus and Greater Caucasus, providing geodetic constraints to the problem. A significant strain rate is observed in a profile over a distance of about 150 km across the Kura Basin. We attribute this to inter-seismic strain accumulation on buried fault structures and present simple elastic dislocation models for their plausible geometry and slip rate based on the known geology, seismicity and the GPS velocities. Due to the close proximity of the strain anomaly to Baku, further observations are needed to determine whether observed contraction is due to inter-seismically locked faults and, if so, implications for the seismic hazard in the region.

SUMMARY The Mw 8.8 Maule earthquake occurred off the coast of central Chile on 2010 February 27 and was the sixth largest earthquake to be recorded instrumentally. This subduction zone event was followed by thousands of aftershocks both near the plate interface and in the overriding continental crust. Here, we report on a pair of large shallow crustal earthquakes that occurred on 2010 March 11 within 15 min of each other near the town of Pichilemu, on the coast of the O’Higgins Region of Chile. Field and aerial reconnaissance following the events revealed no distinct surface rupture. We infer from geodetic data spanning both events that the ruptures occurred on synthetic SW-dipping normal faults. The first, larger rupture was followed by buried slip on a steeper fault in the hangingwall. The fault locations and geometry of the two events are additionally constrained by locations of aftershock seismicity based on the International Maule Aftershock Data Set. The maximum slip on the main fault is about 3 m and, consistent with field results, the onshore slip is close to zero near the surface. Satellite radar data also reveal that significant aseismic afterslip occurred following the two earthquakes. Coulomb stress modelling indicates that the faults were positively stressed by up to 40 bars as a result of slip on the subduction interface in the preceding megathrust event; in other words, the Pichilemu earthquakes should be considered aftershocks of the Maule earthquake. The occurrence of these extensional events suggests that regional interseismic compressive stresses are small. Several recent large shallow crustal earthquakes in the overriding plate following the 2011 Mw 9.0 Tohoku-Oki earthquake in Japan may be an analogue for the triggering process at Pichilemu.

Bulk platinum-rich glasses exhibiting high bulk moduli and Poisson ratios are introduced. A bulk modulus of 217 GPa and a Poisson’s ratio of 0.43 are measured, the highest values reported to date for a metallic glass. The present glasses demonstrate an unusual capacity for “liquid-like” deformation characterized by low resistance to shear flow and high resistance to cavitation, enabling extensive bending ductility in the absence of fracture. An indirect estimate of the fracture toughness yields a value of ∼125 MPa m^(1/2).