Seismic Changes Research Articles

Eye genes: Looking forward, glancing back

AbstractWhen we began the identification of genes implicated in eye disease, the process was slow and laborious. It is three decades since we identified PAX6 as the gene mutated in aniridia, before the launch of the Human Genome Project. Since then there have been seismic changes in technology: in sequencing, gene expression studies, including database generation and data mining and the use of AI (artificial intelligence). The building of the Human Cell Atlas is revolutionizing our understanding of microanatomy. Patient phenotyping has also evolved with great strides in ocular imaging and psychophysics. Two decades ago, we identified further key eye development genes, SOX2 and OTX2, implicated in anophthalmia and microphthalmia. Together with retinal disease gene discovery, the era of functional network building began. Our interests encompassed defining not only coding region mutations—now much aided by advances in protein structure prediction—but also non‐coding regulatory variation. Exploration of dynamic and established genome organization is contributing to improved understanding of these aspects normal and abnormal function. Our speedy tour will take us through much territory.

Time Bomb from the West: Video, the Advertising Industry, and Consumer Culture in Late-Socialist Czechoslovakia

Time Bomb from the West: Video, the Advertising Industry, and Consumer Culture in Late-Socialist Czechoslovakia

Advanced monitoring of tailings dam performance using seismic noise and stress models

Tailings dams retain the waste by-products of mining operations and are among the world’s largest engineered structures. Recent tailings dam failures highlight important gaps in current monitoring methods. Here we demonstrate how ambient noise interferometry can be applied to monitor dam performance at an active tailings dam using a geophone array. Seismic velocity changes of less than 1% correlate strongly with water level changes at the adjacent tailings pond. We implement a power-law relationship between effective stress and shear wave velocity, using the pond level recordings with shear wave velocity profiles obtained from cone penetration tests to model changes in shear wave velocities. The resulting one-dimensional model shows good agreement with the seismic velocity changes. As shear wave velocity provides a direct measure of soil stiffness and can be used to infer numerous other geotechnical design parameters, this method provides important advances in understanding changes in dam performance over time.

Editorial

This special issue of the Journal of Higher Education in Africa examines global debates concerned with higher education as a public good, in the context of the lived realities, political and economic constraints as well as opportunities in contemporary Africa. While the articles draw on research and analysis conducted from 2017 to 2019, and were completed before the seismic changes associated with the COVID pandemic, the framing ideas regarding a contextualised understanding of the relationship between higher education and the public good are highly resonant with the processes of the COVID conjuncture. In this Editorial, we distil the key ideas that have shaped this collection of works, describe the research study that connected them, and draw out some of the implications of the findings for thinking about higher education and the public good in the light of the major disruptions of 2020–2021 for higher education in many African countries.

Assessing similarity in continuous seismic cross-correlation functions using hierarchical clustering: application to Ruapehu and Piton de la Fournaise volcanoes

SUMMARY Passive seismic interferometry has become a popular technique towards monitoring. The method depends on the relative stability of background seismic sources in order to make repeatable measurements of subsurface properties. Such stability is typically assessed by examining the similarity of cross-correlation functions through time. Thus, techniques that can better assess the temporal similarity of cross-correlation functions may aid in discriminating between real subsurface processes and artificial changes related variable seismic sources. In this study, we apply agglomerative hierarchical clustering to cross-correlation functions computed using seismic networks at two volcanoes. This allows us to form groups of data that share similar characteristics and also, unlike common similarity measures, does not require a defined reference period. At Piton de la Fournaise (La Réunion island), we resolve distinct clusters that relate both to changes in the seismic source (volcanic tremor onset) and changes in the medium following volcanic eruptions. At Mt Ruapehu (New Zealand), we observe a consistency to cross-correlation functions computed in the frequency band of volcanic tremor, suggesting tremor could be useful as a repeatable seismic source. Our results demonstrate the potential of hierarchical clustering as a similarity measure for cross-correlation functions, suggesting it could be a useful step towards recognizing structure in seismic interferometry data sets. This can benefit both decisions in processing and interpretations of observed subsurface changes.

Correlation between Seismic Waves Velocity Changes and the Occurrence of Moderate Earthquakes at the Bending of the Eastern Carpathians (Vrancea)

Seismic velocity is the geophysical property that has a key role in characterizing dynamic processes and the state of the stress around the faults, providing valuable information regarding the change in the tectonic regime. The stress in the crust is an important indicator of the possible occurrence of a major earthquake, and the variation of seismic velocities, in time, can provide a clearer picture on the tectonic processes taking place in the region. In the crust, velocities change before, during, and after earthquakes through several mechanisms related to fault deformations, pore pressure, stress changes, and recovery processes. In this study, we investigate the possible correlation between the changes of seismic velocities (Vp/Vs) in time and the occurrence of moderate size crustal and intermediate depth earthquakes from the Vrancea region. Our findings show that there are no significant variations in Vp/Vs for the intermediate depth earthquakes, while crustal events have decreased seismic activity prior to the main earthquake and no high Vp/Vs anomalies. Our results indicate key aspects, and such analyses should be carried out in real-time to continuously explore any unusual pattern pointed out by the seismic velocity changes. Vp/Vs and their standard errors can also be used to describe seismic activity patterns that shape the tectonic evolution of the area.

On 3D printed meta-structure-based functional prototype as an innovative solution for repair and online health monitoring of heritage structures

• Dual-material 3D-printed meta -structure of polyvinylidene fluoride (PVDF)-graphene (Gr)-Mn-doped ZnO and PVDF-CaCO 3. • Repair and health monitoring solution for non-structural cracks in heritage buildings. • Effect of joint length and angle of meta -structure for acceptable electrical and mechanical properties. • 3D printed IoT-based solution for a repaired crack of heritage structures. In the recent past, some studies have been reported on the internet of things (IoT) based 3D printed solutions for heritage structure health monitoring (HSHM). But hitherto little has been reported on dual-material 3D-printed meta -structure-inspired IoT-based solutions, to assist HSHM (in form of varying modulus of toughness (MoT), strain hardening coefficient, stiffness to accommodate the seismic changes, weathering effect, etc.). This study reports the dual-material 3D-printed meta -structure of polyvinylidene fluoride (PVDF)-6%graphene (Gr)-3%Mn-doped ZnO and PVDF-6%CaCO 3 composite as a repair and health monitoring solution (operatable in industry scientific medicine (ISM) band using Bluetooth application). The mechanical properties and sensing features (of dual-material 3D-printed sandwich meta -structure) were tested for the HSHM. The results highlighted that tri-hexagonal meta -structure is one of the acceptable solutions for the fabrication of 3D printed functional prototypes for online HSHM. For the proposed tri-hexagonal meta -structure, return loss (S 11 ) 2.51 GHz, MoT (0.94GPa), and strain hardening coefficient (78.55 MPa) were observed, and correspondingly the effect of joint length and angle was also explored.

Spatio-temporal changes in degassing behavior at Stromboli volcano derived from two co-exposed SO2 camera stations

Improving volcanic gas monitoring techniques is central to better understanding open-vent, persistently degassing volcanoes. SO2 cameras are increasingly used in volcanic gas studies, but observations are commonly limited to one single camera alone viewing the volcanic plume from a specific viewing direction. Here, we report on high frequency (0.5 Hz) systematic measurements of the SO2 flux at Stromboli, covering a 1-year long observation period (June 2017-June 2018), obtained from two permanent SO2 cameras using the same automated algorithm, but imaging the plume from two different viewing directions. Our aim is to experimentally validate the robustness of automatic SO2 camera for volcano monitoring and to demonstrate the advantage of using two co-exposed SO2 camera stations to better capturing degassing dynamics at open-vent volcanoes. The SO2 flux time-series derived from the two SO2 camera stations exhibit good match, demonstrating the robustness of the automatic SO2 camera method. Our high-temporal resolution SO2 records resolve individual Strombolian explosions as transient, repetitive gas bursts produced by the sudden release of over pressurized gas pockets and scoriae. Calculations show that explosive degassing activity accounts for ∼10% of the total SO2 emission budget (dominated by passive degassing) during mild regular open-vent activity. We show that the temporal variations of the explosive SO2 flux go in tandem with changes in total SO2 flux and VLP seismicity, implicating some commonality in the source processes controlling passive degassing and explosive activity. We exploited the spatial resolution of SO2 camera to discriminate degassing at two distinct regions of the crater area, and to minimize biases due by the station position respect to the target plume. We find that the SO2 fluxes from southwest-central (SWCC) and northeast (NEC) crater areas oscillate coherently but those from the NEC are more sensitive to the changes in the volcanic intensity. We interpret this as due to preferential gas/magma channeling into the structurally weaker north-eastern portion of the crater terrace in response to increasing supply rate of buoyant, bubble-rich magma in the shallow plumbing system.

Seismic velocity changes in the Groningen reservoir associated with distant drilling

In this study, we show that passively recorded data of nearby passing trains by a deep borehole geophone array could be linked to fluctuations of the gas-water contact in the Groningen reservoir in The Netherlands. During a period of 1.5 months, changes of inter-geophone P-wave travel times were detected by deconvolution interferometry of the recorded train signals. P-to-S converted waves, obtained by deconvolution of the horizontal component by the vertical component at individual geophones, showed simultaneous variations. The observed travel-time changes could be related to fluctuations of the gas-water contact in the observation well caused by pressure variations at a well drilling 4.5 km away. The sim 3.5 day delay between drilling in the reservoir and the seismic response yields a hydraulic diffusivity of approximately 5 m^2/s and suggests that the pressure front is effectively propagated over such a long distance. Our observations illustrate that downhole geophone arrays can be used to monitor changes in the subsurface if repeating noise sources are available, and that unexpected effects may occur due to drilling.

A combination of tides and nontidal variations in ocean bottom pressure may generate interannual slip fluctuations in the transition zone along a subduction plate interface

The tidal triggering of earthquakes has been studied for many years. The discovery of slow earthquakes in the early 2000s, including slow slip, has urged scientists to investigate the tidal responses of these earthquakes due to their sensitivity to weak stress perturbations. Previous studies have shown that slow earthquakes correlate with diurnal and semidiurnal tides and seasonal variations in surface loads more clearly than ordinary earthquakes. However, little is known about long-term responses to external stresses. In this paper, based on a widely accepted frictional law for faults, a mechanism is proposed by which nontidal variations in ocean bottom pressure, when combined with tides, promote the occurrence of slow earthquakes. Because slow earthquakes accompany a slip on the plate interface, this mechanism allows one to estimate slip modulations. A one-degree-of-freedom slip model is constructed and applied to Ise Bay in the Tonankai region of southwestern Japan, where large-scale ocean mass redistributions have occurred. The model calculated with parameters determined from the observation of tectonic tremors is quantitatively consistent with the slip during 1997–2013 inferred from GNSS data, suggesting that the decrease in the sea-level change in approximately 2006 could cause the acceleration of a slip observed after that. This result implies that the decreases in sea level in approximately 1996 and 2014 could also cause subsequent slip accelerations. These three slip acceleration periods temporally coincide with the increases in background seismicity in a shallower portion of the plate interface. These changes in seismicity are common to shallow earthquakes in the Tokai area, and a similar model can reproduce them. Further studies are expected to reveal causality between shallow earthquakes and long-term slip fluctuations based on modeling that considers changes in the frictional property along the plate interface.

Spatio-temporal variations of shallow seismic velocity changes in Salton Sea Geothermal Field, California in response to large regional earthquakes and long-term geothermal activities

We measure spatio-temporal variations of seismic velocity changes in Salton Sea Geothermal Field, California based on cross correlations of daily seismic traces recorded by a borehole seismic network from December 2007 to January 2014. We find clear co-seismic velocity reductions during the 2010 M 7.2 ​El Mayor–Cucapah, Mexico earthquake at ∼100 ​km further south, followed by long-term recoveries. The co-seismic reductions are larger with longer post-seismic recoveries in higher frequency bands, indicating that material damage and healing process mostly occurred in the shallow depth. In addition, the co-seismic velocity reductions are larger for ray paths outside the active fluid injection/extraction regions. The ray paths inside injection/extraction regions are associated with smaller co-seismic reductions, but subtle long-term velocity increases. We also build 3D transient water flow models based on monthly injection/extraction rates, and find correlations between several water flow parameters and co-seismic velocity reductions. We interpret the relative lack of co-seismic velocity changes within the geothermal region as unclogging of fracture network due to persistent fluid flows of geothermal production. The long-term velocity increase is likely associated with the ground water depletion and subsidence due to net production.

Queer Anxieties of Young Adult Literature and Culture

Queer Anxieties of Young Adult Literature and Culture

Monitoring Seismic Velocity Changes Across the San Jacinto Fault Using Train-Generated Seismic Tremors.

Microseismic noise has been used for seismic velocity monitoring. However, such signals are dominated by low-frequency surface waves that are not ideal for detecting changes associated with small tectonic processes. Here we show that it is possible to extract stable, high-frequency body waves using seismic tremors generated by freight trains. Such body waves allow us to focus on small velocity perturbations in the crust with high spatial resolution. We report on 10 years of seismic velocity temporal changes at the San Jacinto Fault. We observe and map a two-month-long episode of velocity changes with complex spatial distribution and interpret the velocity perturbation as produced by a previously undocumented slow-slip event. We verify the hypothesis through numerical simulations and locate this event along a fault segment believed to be locked. Such a slow-slip event stresses its surroundings and may trigger a major earthquake on a fault section approaching failure.

Unlearning school attendance and its problems: Moving from historical categories to postmodern dimensions

School attendance and its problems have been a focus of myriad stakeholders for over a century, which has led both to important advancements in this area as well as compartmentalized categorical approaches to explain at least part of the vast ecology of these issues. Recent seismic events and changes, however, have provided a unique opportunity to unlearn calcified notions of school attendance and its problems and to consider more inclusive paradigms. This article focuses on several categorical approaches that have been historically a focus of research, health-based clinical work, and educational and social policy in this area: defining school attendance problems, demarcating school attendance problems, subtyping school attendance problems, risk and protective factors for school attendance/problems, interventions for school attendance problems, and school completion. For each area, alternative dimensional approaches are discussed that are emerging from different disciplines and that may provide additional flexibility and comprehensiveness for avenues of endeavor relevant to a postmodern era. The article concludes with a call to abandon historical, discipline-specific, categorical silos in favor of a spectrum of postmodern, multidisciplinary systemic-analytic collaborations and shared alliances to better conceptualize and manage the full ecology of school attendance and its problems.

Temporal changes of seismicity in Salton Sea Geothermal Field due to distant earthquakes and geothermal productions

SUMMARY The Salton Sea Geothermal Field (SSGF) is one of the most seismically active and geothermally productive fields in California. Here we present a detailed analysis of short-term seismicity change in SSGF from 2008 to 2013 during and right following large distant earthquakes, as well as long-term seismicity change due to geothermal productions. We first apply a GPU-based waveform matched-filter technique (WMFT) to the continuous data recorded by the Calenergy Borehole (EN) Network and detect more than 70 000 new micro-earthquakes than listed in the standard Southern California Seismic Network catalogue. We then analyse the seismicity rate changes in the SSGF associated with transient stress fluctuations triggered by regional and large teleseismic earthquakes from 1999 to 2019. We find triggered seismicity in the SSGF following seven regional M > 5.5 earthquakes. In comparison, most teleseismic earthquakes with M > 8.0 did not trigger significant seismicity rate change in the SSGF, likely indicating a frequency dependence in remote dynamic triggering. We further characterize the correlation between the long-term seismicity rate and geothermal production rates, and the temporal and spatial distribution of Guttenberg–Richter b-values inside and outside the SSGF with the newly detected catalogue. The long-term seismicity shows that events with M > 1.5 are likely correlated with net production rates, while smaller events do not show any correlation. The b-values inside the SSGF are higher than those outside the SSGF, and the locations of dynamically triggered events are close to locations with high b-values.

A machine‐learning framework to estimate saturation changes from 4D seismic data using reservoir models

Time-lapse seismic (four-dimensional seismic) data play a preeminent role in closed-loop reservoir management by providing a full-field image of dynamic reservoir behaviour during production. Nonetheless, the multidisciplinary nature of four-dimensional closed-loop approaches demands more quantitative and fast methods to integrate rock physics models, reservoir flow simulation models and four-dimensional seismic analysis. In this work, we tackle this time-consuming and expensive process and develop a data-driven quantitative approach to leverage the inherent physics between four-dimensional seismic and reservoir property changes. We propose an inversion flow method using machine learning strategies to estimate changes in reservoir properties directly from a fast-derived four-dimensional seismic attribute. This study was carried out in a Brazilian deep-water field where production started in 2013 with 3 years of production and injection history. For this reservoir, the estimation of fluid saturation maps is a critical objective to assist engineers with data assimilation procedures. We also generated millions of training data samples using 200 simulation models from the field mentioned above (before history matching) to highlight the benefits of restricting training samples to proper fluid flow consistent combinations. Results demonstrate high prediction accuracy for the targeted reservoir property changes. Additionally, it provides insights for the detection of sweet spots and positioning of infill wells. We significantly simplify the four-dimensional seismic integration process, allowing initial engagements of reservoir engineers with decision-making processes and data assimilation applications.

Space-time monitoring of groundwater fluctuations with passive seismic interferometry

Historic levels of drought, globally, call for sustainable freshwater management. Under pressing demand is a refined understanding of the structures and dynamics of groundwater systems. Here we present an unconventional, cost-effective approach to aquifer monitoring using seismograph arrays. Employing advanced seismic interferometry techniques, we calculate the space-time evolution of relative changes in seismic velocity, as a measure of hydrological properties. During 2000–2020 in basins near Los Angeles, seismic velocity variations match groundwater tables measured in wells and surface deformations inferred from satellite sensing, but the seismological approach adds temporal and depth resolutions for deep structures and processes. Maps of long-term seismic velocity changes reveal distinct patterns (decline or recovery) of groundwater storage in basins that are adjacent but adjudicated to water districts conducting different pumping practices. This pilot application bridges the gap between seismology and hydrology, and shows the promise of leveraging seismometers worldwide to provide 4D characterizations of groundwater and other near-surface systems.

Construction and use of real-time seismic velocity change detection system to monitor the temporal and spatial changes of crustal stress and fault activity in Taiwan

Taiwan is a hotbed of seismic and orogeny activity and this is the basis of the research of Dr Hsin-Hua Huang, Earth Structures Laboratory, Institute of Earth Sciences, Academia Sinica, Taiwan. He has illuminated detailed crustal and slab structures that have furthered understanding of Taiwan orogeny, incorporated ambient noise data to resolve high-resolution imaging of the volcanic and fault structure in northern Taiwan and conducted research that led to the discovery of multi-layering magma beneath the Yellowstone supervolcano in the US. The ultimate goal of his diverse studies is to achieve an improved imaging of the structure of the Earth and establish better understanding of the orogenic tectonic process and assess and mitigate natural hazards, such as volcanoes and earthquakes. In their latest project, Huang and the team are using the seismic wave interferometry method, combined with Taiwan's existing real-time signal transmission Taiwan Broadband Seismic Network (BATS) and the Central Weather Bureau Seismic Network (CWB24), to develop an automated real-time seismicity change detection system. The idea is that by measuring changes in the transmission velocity of seismic waves in the crust, physical parameters such as the degree of rock compression or changes in porosity can be linked and discussed. The researchers have performed an extensive review of knowledge about the current stage of fault zone failure and healing processes,the advantages of seismic noise interferometry and the need for Taiwan fault zone monitoring and related seismic interferometry research. In order to understand the temporal changes in crustal structure and the behaviour of velocity changes across faults, a long-term and stable real-time seismic velocity change monitoring system is necessary.

The Use of Modern Technologies in Post-COVID-19 Cardiopulmonary Rehabilitation

Managing cardiopulmonary rehabilitation in patients with COVID-19 remains a global challenge due to the facets of this virus. The technologies used in the rehabilitation of post-COVID-19 patients fail to keep pace with the global epidemiological developments. The purpose of this article is to review the medical technologies used in post-COVID-19 cardiopulmonary rehabilitation and the innovations that have allowed us to adapt and care for our patients. The pandemic highlighted the need for seismic changes in diagnostic and rehabilitation paradigms. We discuss advances in telemedicine and telemedicine-based rehabilitation, remote patient monitoring and emerging technologies used in cardiopulmonary rehabilitation. The rapid adoption of modern technologies in the practice of post-COVID-19 cardiopulmonary rehabilitation is promising and can improve patients’ access to complex rehabilitation programs with outstanding results.

Covid-19 and the lost hidden curriculum: locating an evolving narrative ecology of Schools-in-Covid

ABSTRACT The Covid-19 pandemic brought seismic changes to children and families, with schools at the forefront of the daily battle to maintain learning. We report on our reflexive thematic analysis of data collected with 28 participants in 14 schools in England during the summer of 2021, following two extensive national lockdowns, and two transition points of returning to school under Covid safety measures. Our data reflects an emerging narrative ecology of Schools-in-Covid, developing as the pandemic continued to unfold for children and families, schools, policy makers and ourselves, in a co-construction of what this pandemic has brought to our lives. We present our findings as a reportage, as our collective experience continues to unfold. Our superordinate themes re-position the UK Government priority of academic catch up as secondary to mental health, and argue the re-establishment of the hidden curriculum was the main vehicle for social and emotional learning (SEL) and wellbeing through direct instruction, modelling and practice, typically associated with improved attitudes about the self, others and school and with consequential higher attainment. We report a partial inversion of expectations; rather than a heavy emphasis towards widening disadvantage, our participants report some benefit to vulnerable children and young people who gained from a changed in-person learning environment, and overwhelming distress to those deemed less vulnerable. Our findings identify Schools in the Community, Care before Curriculum, Agility (adapt, survive and thrive), and Reflective and Responsive, as the key aspects of an emerging narrative ecology of Schools-in-Covid.