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We report the first detection of unrest at Socompa volcano during our recent survey of Central Andean volcanos in Northern Chile using Interferometric Synthetic Aperture Radar measurements spanning January 2018 to October 2021. We find that Socompa volcano, whilst initially undeforming and no recorded eruptions for 7.2 kyr, shows a steady uplift (17.5 mm/yr) from November 2019, independently recorded by near‐field continuous Global Positioning System data. The deformation pattern can be fitted with pressure increase in an ellipsoidal source region stretching from 2.1 to 10.5 km, with a volume change rate of ∼6.2 × 106 m3/yr. Our observations of the onset of uplift suggest it is unlikely that a nearby Mw 6.8 deep intraslab earthquake on 3 June 2020 triggered the unrest. The deformation signal we detect indicates the initiation of unrest at Socompa, after at least two decades without measurable deformation, and many thousands of years without volcanic activity. Plain Language Summary: Here we report the first observation of unrest of the Socompa volcano, Northern Chile, which is thought to have last erupted thousands of years ago. Using radar interferometry technique and differencing radar images from two dates, it is possible to retrieve millimeter‐level surface displacements during this period. Here, we use a time series of multiple images spanning January 2018 to January 2023, over the Central Andean volcanoes in Northern Chile, to estimate the change in ground movement through time. Combined with Global Positioning System data, we find Socompa volcano started to uplift in November 2019 at a relatively stable speed (of 17.5 mm/yr) without any trace of slowing down up to December 2021. Our analysis suggests that this volcanic deformation is unlikely to have been triggered by a nearby 112 km depth, Mw 6.8 earthquake, which occurred in June 2020, and was thus after the onset time. Deformation at Socompa has similarities with other volcanoes in the Central Andes, where low rates of magmatic uplift have been detected at other apparently quiescent volcanoes. Such large‐scale monitoring efforts using remote sensing data are important, as we can better understand the deformation style of these volcanoes in areas that are poorly instrumented. Key Points: We combine Interferometric Synthetic Aperture Radar and Global Positioning System data to survey the Central Andean volcanoes, some of which have been updated for the first time in over 10 yearsWe show the first detection of unrest at Socompa volcano with steady uplift up to 17.5 mm/yr since November 2019Deformation patterns are consistent with an ellipsoidal source, stretching from 2.1 to 10.5 km and with a volume change of ∼6.2 × 106 m3/yr [ABSTRACT FROM AUTHOR]

Interferometric Synthetic Aperture Radar (InSAR) is an established method to measure earthquake surface displacements. However, due to decorrelation and atmospheric noise, only a certain fraction of earthquakes is readily observable with single interferograms. To enhance the potential of retrieving InSAR earthquake observations, we apply InSAR time series analysis and use several recent earthquakes (Mw 5.6–6.3, 2018–2019) in Iran as case studies. We find that the coseismic displacement signals of these earthquakes, which might not be discernible within single interferograms, are better resolved using our approach. We reconstruct the coseismic deformation fields by fitting surface displacements using a time series approach. We find that the reconstructed coseismic deformation fields yield more robust and seismologically consistent earthquake modeling results when compared to single coseismic interferograms. Our work suggests that a time series approach is an effective way to improve the resolving power of InSAR for earthquake studies. Plain Language Summary: Earthquakes cause the ground to temporarily shake, but also result in permanent movement of the surface of the Earth. This surface displacement can be detected using sensitive radar echoes from satellites when it is large enough. By differencing phases of radar images from before and after the earthquake (a technique known as interferometry), it is possible to detect where an earthquake has happened and determine its source parameters. However, the atmosphere and different imaging conditions cause noise in individual interferogram images, masking the earthquake movement. Here, we use a method involving a time series of multiple images before and after the earthquake to improve the picture of the earthquake by observing how the estimates of ground movement change through time. We therefore improve measurement of the distribution and amount of ground movement, allowing the detection of smaller earthquakes than before. Using a sequence of recent earthquakes in Iran as a test case, our method improves the assessment of the type and the location of detected earthquakes compared with single image interferogram data (average 36% uncertainty reduction), with the validation from seismic data. Our work demonstrates the enhancement of this time series approach and its potential in future earthquake studies. Key Points: Using time series analysis, we can detect small coseismic displacements that are not readily visible or ambiguous in single interferogramsEarthquakes occurring close in time and space can be separated by a time‐dependent parameterized model fitted to Interferometric Synthetic Aperture Radar time series analysisWe can achieve more robust and seismologically consistent earthquake modeling results by using a time series approach [ABSTRACT FROM AUTHOR]

In this paper, we illustrate some of the current methods for the exploitation of data from Earth Observing satellites to measure and understand earthquakes and shallow crustal tectonics. The aim of applying such methods to Earth Observation data is to improve our knowledge of the active fault sources that generate earthquake shaking hazards. We provide examples of the use of Earth Observation, including the measurement and modelling of earthquake deformation processes and the earthquake cycle using both radar and optical imagery. We also highlight the importance of combining these orbiting satellite datasets with airborne, in situ and ground-based geophysical measurements to fully characterise the spatial and timescale of temporal scales of the triggering of earthquakes from an example of surface water loading. Finally, we conclude with an outlook on the anticipated shift from the more established method of observing earthquakes to the systematic measurement of the longer-term accumulation of crustal strain. [ABSTRACT FROM AUTHOR]

Earthquakes pose a significant hazard, and due to the growth of vulnerable, exposed populations, global levels of seismic risk are increasing. In the past three decades, a dramatic improvement in the volume, quality and consistency of satellite observations of solid earth processes has occurred. I review the current Earth Observing (EO) systems commonly used for measuring earthquake and crustal deformation that can help constrain the potential sources of seismic hazard. I examine the various current contributions and future potential for EO data to feed into aspects of the earthquake disaster management cycle. I discuss the implications that systematic assimilation of Earth Observation data has for the future assessment of seismic hazard and secondary hazards, and the contributions it will make to earthquake disaster risk reduction. I focus on the recent applications of Global Navigation Satellite System (GNSS) and increasingly the use of Interferometric Synthetic Aperture Radar (InSAR) for the derivation of crustal deformation and these data's contribution to estimates of hazard. I finish by examining the outlook for EO in geohazards in both science and decision-making, as well as offering some recommendations for an enhanced acquisition strategy for SAR data. [ABSTRACT FROM AUTHOR]

The relationship between individual earthquakes and the longer-term growth of topography and of geological structures is not fully understood, but is key to our ability to make use of topographic and geological data sets in the contexts of seismic hazard and wider-scale tectonics. Here we investigate those relationships at an active fold-and-thrust belt in the southwest Tarim Basin, Central Asia. We use seismic waveforms and interferometric synthetic aperture radar (InSAR) to determine the fault parameters and slip distribution of the 2015 M w6.3 Pishan earthquake-a blind, reverse-faulting event dipping toward the Tibetan Plateau. Our earthquake mechanism and location correspond closely to a fault mapped independently by seismic reflection, indicating that the earthquake was on a preexisting ramp fault over a depth range of ∼9-13 km. However, the geometry of folding in the overlying fluvial terraces cannot be fully explained by repeated coseismic slip in events such as the 2015 earthquake nor by the early postseismic motion shown in our interferograms; a key role in growth of the topography must be played by other mechanisms. The earthquake occurred at the Tarim-Tibet boundary, with the unusually low dip of 21°. We use our source models from Pishan and a 2012 event to argue that the Tarim Basin crust deforms only by brittle failure on faults whose effective coefficient of friction is ≤0.05 ± 0.025. In contrast, most of the Tibetan crust undergoes ductile deformation, with a viscosity of order 1020-1022 Pa s. This contrast in rheologies provides an explanation for the low dip of the earthquake fault plane. [ABSTRACT FROM AUTHOR]

The 2011 October 23 MW 7.1 Van earthquake in eastern Turkey caused ~600 deaths and caused widespread damage and economic loss. The seismogenic rupture was restricted to 10-25 km in depth, but aseismic surface creep, coincident with outcrop fault exposures, was observed in the hours to months after the earthquake. We combine observations from radar interferometry, seismology, geomorphology and Quaternary dating to investigate the geological slip rate and seismotectonic context of the Van earthquake, and assess the implications for continuing seismic hazard in the region. Transient post-seismic slip on the upper Van fault started immediately following the earthquake, and decayed over a period of weeks; it may not fully account for our long-term surface slip-rate estimate of ≥0.5 mm yr-1. Post-seismic slip on the Bostanic,i splay fault initiated several days to weeks after the main shock, and we infer that it may have followed the MW 5.9 aftershock on the 9th November. The Van earthquake shows that updip segmentation can be important in arresting seismic ruptures on dip-slip faults. Two large, shallow aftershocks show that the upper 10 km of crust can sustain significant earthquakes, and significant slip is observed to have reached the surface in the late Quaternary, so there may be a continuing seismic hazard from the upper Van fault and the associated splay. The wavelength of folding in the hanging wall of the Van fault is dominated by the structure in the upper 10 km of the crust, masking the effect of deeper seismogenic structures. Thus, models of subsurface faulting based solely on surface folding and faulting in regions of reverse faulting may underestimate the full depth extent of seismogenic structures in the region. In measuring the cumulative post-seismic offsets to anthropogenic structures, we show that Structure-from-Motion can be rapidly deployed to create snapshots of postseismic displacement. We also demonstrate the utility of declassified Corona mission imagery (1960s-1970s) for geomorphic mapping in areas where recent urbanization has concealed the geomorphic markers. [ABSTRACT FROM AUTHOR]

Determining the relationship between folding and faulting in fold and thrust belts is important for understanding the growth of geological structures, the depth extent of seismic slip, and consequently, the potential earthquake hazard. The 2013 Mw 6.2 Khaki‐Shonbe earthquake occurred in the Simply Folded Belt of the Zagros Mountains, Iran. We combine seismological solutions, aftershock relocations, satellite interferometry, and field observations to determine fault geometry and its relationship with the structure, stratigraphy, and tectonics of the central Zagros. We find reverse slip on two along‐strike, southwest dipping fault segments. The main shock rupture initiated at the lower northern end of the larger northwest segment. Based upon the hypocenter and rupture duration, slip on the smaller southern segment is likely aseismic. Both faults verge away from the foreland, toward the high‐range interior, contrary to the fault geometries depicted in many structural cross sections of the Zagros. The modeled slip occurred over two mutually exclusive depth ranges above 10 km, resulting in long (∼16 km), narrow rupture segments (∼7 km). Aftershocks cluster in the depth range 3–14 km. This indicates reverse slip and coseismic shortening occurred mostly or exclusively in the sedimentary cover, with slip distributions likely to be lithologically controlled in depth by the Hormuz salt at the base of the sedimentary cover (∼10–12 km), and the Kazhdumi Formation mudrocks at upper levels (∼4–5 km). Our findings suggest lithology plays a significant role in the depth extent of slip found in reverse faults in folded belts, providing an important control on the potential size of earthquakes. [ABSTRACT FROM AUTHOR]

A model predictive controller (MPC) in the form of dynamic matrix control (DMC) is implemented for attenuating in-plane vibrations of a two flexible link planar manipulator. The rotation of the joints and inertia effect of both the joints and links induce vibration. Piezoelectric actuators, mounted in a bimorph configuration, provide the control actions to reduce vibrations. Implementation of this control scheme is shown to provide appreciable attenuation of vibration over the uncontrolled case, increasing the damping ratio for the first and second link by a factor of 5.99 and 3.40, respectively. DMC control is further shown to reduce the mean amplitude of dominant vibrations from the uncontrolled case by 90.0% and 87.4%, respectively, for the first and second links. Furthermore, for the two link setup, this control is shown to outperform the more conventional ProportionalIntegral-Derivative (PID) control and is sufficiently robust to handle an unknown payload. [ABSTRACT FROM AUTHOR]

A finite element based model predictive controller (FEMPC) is developed and practically implemented for attenuating in-plane vibration of a two flexible link planar manipulator. This FEMPC structure is based on that used in dynamic matrix control (DMC), with the exception that a finite element (FE) model replaces how the predictions are formulated. A linear FE model is developed for each individual link, which is used with the current measured strain and control actions, to predict the response of each link. These predictions are carried out at each time step to address the geometric non-linearities associated with the orientation of the second link and those associated with friction, backlash and compliance of the geared motors. Furthermore, the use of FE modelling enables the control structure to be formulated based on known properties of the system, eliminating the need for open loop testing. The resulting FEMPC scheme is shown to outperform DMC and is capable of providing substantial attenuation of vibration, reducing the mean amplitude of dominant vibration by 92.5% and 15.6%, for the first and second links, respectively. [ABSTRACT FROM AUTHOR]

In 2011 two significant earthquakes tested the world's most seismically resilient communities: the Christchurch earthquake in New Zealand and the Tohoku earthquake in Japan. These events challenged some of the best enforced, high-quality seismic building codes in the world and shocked two resilient communities. Although both countries coped extremely well, the concern lies with the many seismically vulnerable countries that are becoming rapidly industrial and urban centric. This commentary briefly examines the Christchurch and Tohuku earthquakes and considers what makes a community resilient and what can be learnt about resilience from 'disasters' in the global North. [ABSTRACT FROM AUTHOR]

We use InSAR and body wave modelling to determine the faulting parameters for a series of five 5.9-7.1 normal faulting earthquakes that occurred during 2008, including the March 20 Yutian earthquake ( 7.1), one of the largest normal faulting events to have occurred recently on the continents. We also study three earlier normal faulting earthquakes that occurred in southern Tibet between 1992 and 2005. Coseismic deformation for each of these eight events is measured with ascending and descending interferograms from ENVISAT, ERS and ALOS SAR data. Elastic dislocation modelling of the line-of-sight InSAR displacements and body wave seismological modelling of and waves are used to estimate fault parameters and are found to be in good agreement for all the events studied. The use of InSAR to measure deformation allows a relatively precise determination of the fault location in addition to resolving the focal plane ambiguity. Only five of the eight events are associated with a clear surface topographic feature, suggesting that an underestimation of the amount of extension would result from using the surface expressions of normal faulting alone. The observations, in all cases, are consistent with slip on planar surfaces, with dips in the range 40-50°, that penetrates the uppermost crust to a depth of 10-15 km. We find no evidence for active low-angle (dip less than 30°) normal faulting. The contribution of the normal faulting to overall extension estimated by summing seismic moments over earthquakes for the past 43 yr is 3-4 mm yr−1, or 15-20 per cent of the rates of extension measured across the plateau using GPS. 85 per cent of the moment release in normal faulting over the past 43 yr has occurred in regions whose surface height exceeds 5 km. This observation adds weight to the suggestions that the widespread normal faulting on the plateau is the result of variations in the gravitational potential energy of the lithosphere. [ABSTRACT FROM AUTHOR]

We investigate the source processes and tectonic significance of two earthquakes that occurred on 2010 December 20 (Mw 6.5) and 2011 January 27 (Mw 6.2) within a desert region south of the town of Rigan, SE Iran. The two earthquakes, which we refer to as the South Rigan events, occurred close to one another at the northern margin of the Shahsavaran mountains: a mainly volcanic chain in which the potential for active faulting has not previously been considered in detail. Surface displacements mapped using SAR interferometry, multiple-event relocation analysis of epicentres, body-waveform modelling and field measurements of surface rupture together reveal that the 2010 December 20 earthquake involved an average of ∼1.3 m right-lateral slip on a vertical fault trending ∼210° whereas the 2011 January 27 resulted from ∼0.6 m of slip on a conjugate left-lateral fault striking ∼310°, parallel to the trend of the Shahsavaran mountains and confined within a zone of increased Coulomb stress from the earlier main shock. The main slip for the 2010 and 2011 main shocks failed to reach the surface though minor cracks and en-echelon fissures were mapped following both events. Some of the surface cracks may have been enhanced during a period of minor afterslip in the days following the 2010 main shock. Using the insights gained from our investigation of the two South Rigan earthquakes we perform a regional reconnaissance of the active faulting using SPOT5 (2.5 m) satellite imagery. We show that distributed ∼N–S right-lateral faulting is widely distributed north of the Shahsavaran mountains. We also show evidence for left-lateral strike-slip faulting parallel to the Shahsavaran mountains, with a component of extension in the east and shortening in the west, which is likely to accommodate regional N–S right-lateral shearing by clockwise rotation about a vertical axis. The distributed strike-slip faulting is closely associated with the distribution of towns and villages and constitutes a continuing hazard to local populations. [ABSTRACT FROM AUTHOR]

We present the results of extensive new molecular dynamic (MD) simulations in the one-phase region for square well fluids with well widths λ  =  1.10, 1.15, 1.20, 1.25, 1.375, 1.50, 1.75, 1.90, 2.0, and 2.10. These data have been used in developing a crossover equation of state (CR EOS) for square-well fluids with well widths 1.1  ≤  λ  ≤  2.1. The CR EOS incorporates non-analytic scaling laws in the critical region, and in the limit of low densities yields the exact second and third virial coefficients. Also in the high-temperature region, it reproduces first-order perturbation theory results. The CR EOS was tested against our new MD simulations, and earlier MD and Monte-Carlo (MC) simulations reported by other authors as well. Excellent agreement between calculated values and simulation data for all SW fluids is observed. In combination with the density-functional theory, the CR EOS is also capable of reproducing surface tension simulations with high accuracy. Application of the CR EOS for solid–liquid equilibrium calculations in combination with the Lennard–Jones and Devonshire cell model for the solid phase, is also discussed. [ABSTRACT FROM AUTHOR]

The geometry and frictional properties of a fault system are key parameters required to understand its seismic behavior. The Main Himalayan Thrust in Nepal is the type example of a continental megathrust and forms part of a fault system which accommodates a significant fraction of India-Eurasia convergence. Despite extensive study of this zone of shortening, the geometry of the fault system remains controversial. Here, we use interseismic, coseismic, and postseismic geodetic data in Nepal to investigate the proposed downdip geometries. We use interseismic and coseismic data from previous studies, acquired before and during the 2015 Mw 7.8 Gorkha earthquake. We then supplement these by processing our own postseismic deformation data, acquired following the Gorkha earthquake. We find that kinematic modeling of geodetic data alone cannot easily distinguish between the previously proposed geometries. We therefore develop a mechanical joint coseismic-postseismic slip inversion which simultaneously solves for the distribution of coseismic slip and rate-strengthening friction parameters. We run this inversion using the proposed geometries and find that they are all capable of explaining the majority of geodetic data. We find values for the rate parameter, a, fromthe rate-and-state friction law that are between 0.8 and 1.6×10-3, depending on the geometry used. These values are in agreement with results from laboratory studies and those inferred from other earthquakes. We suggest that the limitations of earthquake cycle geodesy partly explain the continued controversy over the geometry and role of various faults in the Nepal Himalaya. [ABSTRACT FROM AUTHOR]

The 2001 Report of the National Confidential Enquiry into Perioperative Deaths recommended that an echocardiogram should be performed on patients with aortic stenosis prior to anaesthesia. In this study we present the patient details, management and outcome of the 272 hip fracture patients with a previously undiagnosed murmur and echocardiographically proven aortic stenosis admitted from 2001-2005 in our hospital. The patients with aortic stenosis were significantly older, and had significantly lower Abbreviated Mental Test Scores, than the control group of 3698 hip fracture patients without aortic stenosis. There were significant trends toward general anaesthesia over spinal anaesthesia, and use of invasive monitoring of blood pressure, as the severity of the aortic stenosis increased. There were no significant trends towards higher 30-day or 1-year mortality rates as the severity of the aortic stenosis increased. Resources for rapid pre-operative echocardiograms should be made available for hip fracture patients as the results have significant implications for their subsequent anaesthetic management. [ABSTRACT FROM AUTHOR]

The 2001 Report of the National Confidential Enquiry into Perioperative Deaths recommended that an echocardiogram should be performed on patients with aortic stenosis prior to anaesthesia. In this study we present the patient details, management and outcome of the 272 hip fracture patients with a previously undiagnosed murmur and echocardiographically proven aortic stenosis admitted from 2001–2005 in our hospital. The patients with aortic stenosis were significantly older, and had significantly lower Abbreviated Mental Test Scores, than the control group of 3698 hip fracture patients without aortic stenosis. There were significant trends toward general anaesthesia over spinal anaesthesia, and use of invasive monitoring of blood pressure, as the severity of the aortic stenosis increased. There were no significant trends towards higher 30-day or 1-year mortality rates as the severity of the aortic stenosis increased. Resources for rapid pre-operative echocardiograms should be made available for hip fracture patients as the results have significant implications for their subsequent anaesthetic management. [ABSTRACT FROM AUTHOR]

The article reports on a research that was conducted to examine continuous improvement for hip fracture patients taking clopidogrel using the Model for Improvement. It mentions that the goal of the research was to reduce delays to operation theatre while providing an effective plan of action if perioperative haemorrhage required intervention. The research found reduction in time to theatre associated with the negative effect of a increase in blood transfusion requirements.

A response by M.E. McBrien, G. Heyburn, M. Stevenson to a letter to the editor about their article "Previously Undiagnosed Aortic Stenosis Revealed by Auscultation in the Hip Fracture Population: Echocardiographic Findings, Management and Outcome" published in a previous issue of the journal.