Superficial simplicity of the 2010 El Mayor–Cucapah earthquake of Baja California in Mexico

The geometry of faults is usually thought to be more complicated at the surface than at depth and to control the initiation, propagation and arrest of seismic ruptures. The fault system that runs from southern California into Mexico is a simple strike-slip boundary: the west side of California and Mexico moves northwards with respect to the east. However, the M_w 7.2 2010 El Mayor–Cucapah earthquake on this fault system produced a pattern of seismic waves that indicates a far more complex source than slip on a planar strike-slip fault. Here we use geodetic, remote-sensing and seismological data to reconstruct the fault geometry and history of slip during this earthquake. We find that the earthquake produced a straight 120-km-long fault trace that cut through the Cucapah mountain range and across the Colorado River delta. However, at depth, the fault is made up of two different segments connected by a small extensional fault. Both segments strike N130° E, but dip in opposite directions. The earthquake was initiated on the connecting extensional fault and 15 s later ruptured the two main segments with dominantly strike-slip motion. We show that complexities in the fault geometry at depth explain well the complex pattern of radiated seismic waves. We conclude that the location and detailed characteristics of the earthquake could not have been anticipated on the basis of observations of surface geology alone

EHealth and Its Role in Supporting Audiological Rehabilitation: Patient Perspectives on Barriers and Facilitators of Using a Personal Hearing Support System With Mobile Application as Part of the EVOTION Study

BACKGROUND: Hearing loss is a major public health challenge. Audiology services need to utilise a range of rehabilitative services and maximise innovative practice afforded by technology to actively promote personalized, participatory, preventative and predictive care if they are to cope with the social and economic burden placed on the population by the rapidly rising prevalence of hearing loss. Digital interventions and teleaudiology could be a key part of providing high quality, cost-effective, patient-centred management. There is currently very limited evidence that assesses the hearing impaired patient perspective on the acceptance and usability of this type of technology. AIM: This study aims to identify patient perceptions of the use of a hearing support system including a mobile smartphone app when used with Bluetooth-connected hearing aids across the everyday life of users, as part of the EVOTION project. METHODS: We applied a questionnaire to 564 participants in three countries across Europe and analysed the following topics: connectivity, hearing aid controls, instructional videos, audiological tests and auditory training. KEY FINDINGS: Older users were just as satisfied as younger users when operating this type of technology. Technical problems such as Bluetooth connectivity need to be minimised as this issue is highly critical for user satisfaction, engagement and uptake. A system that promotes user-controllability of hearing aids that is more accessible and easier to use is highly valued. Participants are happy to utilise monitoring tests and auditory training on a mobile phone out of the clinic but in order to have value the test battery needs to be relevant and tailored to each user, easy to understand and use. Such functions can elicit a negative as well as positive experience for each user. CONCLUSION: Older and younger adults can utilise an eHealth mobile app to complement their rehabilitation and health care. If the technology works well, is tailored to the individual and in-depth personalised guidance and support is provided, it could assist maximisation of hearing aid uptake, promotion of self-management and improving outcomes

The 2011 Magnitude 9.0 Tohoku-Oki Earthquake: Mosaicking the Megathrust from Seconds to Centuries

Geophysical observations from the 2011 moment magnitude (M_w) 9.0 Tohoku-Oki, Japan earthquake allow exploration of a rare large event along a subduction megathrust. Models for this event indicate that the distribution of coseismic fault slip exceeded 50 meters in places. Sources of high-frequency seismic waves delineate the edges of the deepest portions of coseismic slip and do not simply correlate with the locations of peak slip. Relative to the M_w 8.8 2010 Maule, Chile earthquake, the Tohoku-Oki earthquake was deficient in high-frequency seismic radiation-a difference that we attribute to its relatively shallow depth. Estimates of total fault slip and surface secular strain accumulation on millennial time scales suggest the need to consider the potential for a future large earthquake just south of this event

Resume transmission: re-reading the work of Felix Gonzalez-Torres

Resume transmission: re-reading the work of Felix Gonzalez-Torre

Accounting for uncertain fault geometry in earthquake source inversions – II: application to the Mw 6.2 Amatrice earthquake, central Italy

International audienceOur understanding of earthquake sources is limited by the availability and the quality of observations and the fidelity of our physical models. Uncertainties in our physical models will naturally bias our inferences of subsurface fault slip. These uncertainties will always persist to some level as we will never have a perfect knowledge of the Earth’s interior. The choice of the forward physics is thus ambiguous, with the frequent need to fix the value of several parameters such as crustal properties or fault geometry. Here, we explore the impact of uncertainties related to the choice of both fault geometry and elastic structure, as applied to the 2016 Mw 6.2 Amatrice earthquake, central Italy. This event, well instrumented and characterized by a relatively simple fault morphology, allows us to explore the role of uncertainty in basic fault parameters, such as fault dip and position. We show that introducing uncertainties in fault geometry in a static inversion reduces the sensitivity of inferred models to different geometric assumptions. Accounting for uncertainties thus helps infer more realistic and robust slip models. We also show that uncertainties in fault geometry and Earth’s elastic structure significantly impact estimated source models, particularly if near-fault observations are available

Accounting for uncertain fault geometry in earthquake source inversions – I: theory and simplified application

International audienceThe ill-posed nature of earthquake source estimation derives from several factors including the quality and quantity of available observations and the fidelity of our forward theory. Observational errors are usually accounted for in the inversion process. Epistemic errors, which stem from our simplified description of the forward problem, are rarely dealt with despite their potential to bias the estimate of a source model. In this study, we explore the impact of uncertainties related to the choice of a fault geometry in source inversion problems. The geometry of a fault structure is generally reduced to a set of parameters, such as position, strike and dip, for one or a few planar fault segments. While some of these parameters can be solved for, more often they are fixed to an uncertain value. We propose a practical framework to address this limitation by following a previously implemented method exploring the impact of uncertainties on the elastic properties of our models. We develop a sensitivity analysis to small perturbations of fault dip and position. The uncertainties of our fixed fault geometry are included in the inverse problem under the formulation of the misfit covariance matrix that combines both prediction and observation uncertainties. We validate this approach with the simplified case of a fault that extends infinitely along strike, using both Bayesian and optimization formulations of a static slip inversion. If epistemic errors are ignored, predictions are overconfident in the data and slip parameters are not reliably estimated. In contrast, inclusion of uncertainties in fault geometry allows us to infer a robust posterior slip model. Epistemic uncertainties can be many orders of magnitude larger than observational errors for great earthquakes (Mw > 8). Not accounting for uncertainties in fault geometry may partly explain observed shallow slip deficits for continental earthquakes. Similarly, ignoring the impact of epistemic errors can also bias estimates of near-surface slip and predictions of tsunamis induced by megathrust earthquakes

Children using a unilateral cochlear implant and contralateral hearing aid: bimodal hearing outcomes when one ear is outside the UK (NICE 2009) audiological criteria for cochlear implantation – a single site case–control study

Introduction In the new revised National Institute for Health & Care Excellence (NICE, TA566, 2019) guidelines for cochlear implantation (CI) have clearly stipulated that the hearing loss must be bilateral. Prior to this revision, children and young people (CYP) with asymmetrical thresholds have been considered for unilateral CI when one ear was in audiological criteria. Children with asymmetrical hearing loss represent an important cohort of potential CI candidates, who will continue to be prevented from benefiting from CI unless evidence is produced to support implantation and maximise subsequent benefit.The aim of this study is to evaluate the ‘real-life’ hearing performance in a group of children who have received a unilateral CI and who have hearing thresholds in the contralateral ear that are outside the current UK NICE 2019 audiological criteria for CI. The contralateral ear will be aided using a conventional hearing aid (HA). The outcomes from this ‘bimodal’ group will be compared with a group of children who have received bilateral CI, and a group of children using bilateral HA, to extend the current knowledge about the different performance levels between bilateral CI, bilateral HA and bimodal hearing in CYP.Methods and analysis Thirty CYP aged 6–17 years old, 10 bimodal users, 10 bilateral HA users and 10 bilateral cochlear implant users will be subjected to a test battery consisting of: (1) spatial release from masking, (2) complex pitch direction discrimination, (3) melodic identification, (4) perception of prosodic features in speech and (5) TEN test. Subjects will be tested in their optimal device modality. Standard demographic and hearing health information will be collected. In the absence of comparable published data to power the study, sample size was determined on pragmatic grounds. Tests are exploratory and for hypothesis generating purposes. Therefore, the standard criterion of p<0.05 will be used.Ethics and dissemination This has been approved by the Health Research Authority and NHS REC within the UK (22/EM/0104). Industry funding was secured via a competitive researcher-led grant application process. Trial results will be subject to publication according to the definition of the outcome presented in this protocol

'Real-life' benefit of hearing preservation cochlear implantation in the paediatric population: a single-site case–control study

Introduction Cochlear implantation with hearing preservation (HPCI) has allowed a cochlear implant (CI) electrode to be implanted while trying to preserve residual acoustic low-frequency hearing. The concept arises from the importance of this low-frequency information and the limitations of a CI in several auditory domains. The combination of electrical hearing with either preserved acoustic hearing or amplified ‘natural’ hearing has the potential to address these issues and enable children with HPCI to closely follow normal auditory development.The aim of this study is to evaluate the ‘real-life’ benefit of preserved acoustic low-frequency hearing in children with a CI, understand the benefits of preserved natural hearing in complex listening situations and so enable parents and children to make an informed choice about implantation. Ultimately, helping to ensure the maximum number of children benefit from this life-changing intervention.Methods and analysis Nineteen ears in children and young people aged 6–17 years old with ‘successful’ HPCI will be subjected to a test battery consisting of: (1) spatial release from masking; (2) complex pitch direction discrimination; (3) melodic identification; (4) perception of prosodic features in speech and (5) threshold equalising noise test. Subjects will be tested in the electro-acoustic stimulation (EAS)/electro-natural stimulation (ENS) and the electric-only (ES) condition, thereby acting as their own control group. Standard demographic and hearing health information will be collected. In the absence of comparable published data to power the study, sample size was determined on pragmatic grounds. Tests are exploratory and for hypothesis-generating purposes. Therefore, the standard criterion of p<0.05 will be used.Ethics and dissemination This study has been approved by the Health Research Authority and NHS Research Ethics Committee (REC) within the UK (22/EM/0017). Industry funding was secured via a competitive researcher-led grant application process. Trial results will be subject to publication according to the definition of the outcome presented in this protocol

sj-xlsx-2-tia-10.1177_23312165221137116 - Supplemental material for Exploring the Correlations Between Measures of Listening Effort in Adults and Children: A Systematic Review with Narrative Synthesis

Supplemental material, sj-xlsx-2-tia-10.1177_23312165221137116 for Exploring the Correlations Between Measures of Listening Effort in Adults and Children: A Systematic Review with Narrative Synthesis by Callum Shields, Mark Sladen, Iain Alexander Bruce, Karolina Kluk and Jaya Nichani in Trends in Hearing</p