5,965 research outputs found
Fault reactivation by fluid injection: insights from laboratory friction experiments with multiple reactivation sequences
No full textHow “good” are real-time ground motion predictions from Earthquake Early Warning systems?
No full textReal-time ground motion alerts, as can be provided by Earthquake Early Warning (EEW) systems, need to be both timely and sufficiently accurate to be useful. Yet how timely and how accurate the alerts of existing EEW algorithms are is often poorly understood. In part, this is because EEW algorithm performance is usually evaluated not in terms of ground motion prediction accuracy and timeliness but in terms of other metrics (e.g., magnitude and location estimation errors), which do not directly reflect the usefulness of the alerts from an end user perspective. Here we attempt to identify a suite of metrics for EEW algorithm performance evaluation that directly quantify an algorithm's ability to identify target sites that will experience ground motion above a critical (user-defined) ground motion threshold. We process 15,553 recordings from 238 earthquakes with M > 5 (mostly from Japan and southern California) in a pseudo-real-time environment and investigate two end-member EEW methods. We use the metrics to highlight both the potential and limitations of the two algorithms and to show under which circumstances useful alerts can be provided. Such metrics could be used by EEW algorithm developers to convincingly demonstrate the added value of new algorithms or algorithm components. They can complement existing performance metrics that quantify other relevant aspects of EEW algorithms (e.g., false event detection rates) for a comprehensive and meaningful EEW performance analysis
How “good” are real-time ground motion predictions from Earthquake Early Warning systems?
No full textAdvancing Real-Time Seismic Risk Mitigation: Probabilistic Earthquake Early Warning and Physics Based Earthquake Triggering Models
No full textThe Kaplan-Meier survival probability among men and women.
No full textThe Kaplan-Meier survival probability among men and women.</p
Applying Depth Distribution of Seismicity to Determine Thermo-Mechanical Properties of the Seismogenic Crust in Southern California: Comparing Lithotectonic Blocks
No full textWe analyze waveform-relocated seismicity (1981–2016) and other geophysical and geological datasets from 16 lithotectonic crustal blocks in southern California. We explore how earthquake depth histograms (EDH) are related to crustal strength, lithology, and temperature of the crust. First, we calculate relative EDHs to quantify the depth distribution of seismicity for each lithotectonic block. Second, we calculate depth profiles of maximum differential stress (“yield strength envelopes”, YSEs) using Byerlee’s law and a non-linear dislocation creep law. We use observed average heat flow values, strain rates, and states of stress to parameterize YSEs for five different crustal candidate lithologies in each lithotectonic block. We assume that seismicity ceases where the mechanical rock strength falls below a critical threshold level, and identify the YSE that best predicts the depth extent of seismicity in each block. The lithologies of the best matching YSEs are found to agree well with expectations from past tectonics: they are mostly quartz-dominated except for the feldspar-rich diorite lithologies in the Great Valley, the southernmost western Sierra Nevada, Inner Continental Borderland, and Rifted crust in the Salton Trough. Similarly, the inferred thermo-mechanical properties, including differential stress, lithology, and geotherms reflect the previously mapped tectonic variability between the 16 lithotectonic blocks. On average, the differential yield stress is smaller and peaks at a shallower depth in hotter and more quartz rich crust but is larger and peaks at greater depths for colder and predominantly diorite crust. The good agreement between the modeled YSEs, the EDHs and tectonic considerations suggests that EDHs indeed reflect long-term geophysical properties of the crust and can be used to infer thermo-mechanical properties at depth. In contrast, shallow seismicity may be more likely to reflect short-term strain transients from fluid flow or recent anthropogenic disturbances
Uncoupling of Behavioral and Metabolic Twenty-Four-Hour Rhythms in Reindeer (Current Biology, Meier et al. 2024): Actigraphy data
No full text<p>Raw reindeer actigraphy data collected and analysed in the course of the study "Uncoupling of Behavioral and Metabolic Twenty-Four-Hour Rhythms in Reindeer" (Current Biology, Meier et al. 2024). Details on data processing and plotting can be found in the published article. Further information and codes can be requested from the first author Sara A. Meier.</p>
Labour Force Behaviour of Men and Women in Elderly Two-Adult Households: Evidence from EU Countries. ENEPRI Research Reports No. 7, 1 April 2005
No full textThis paper studies the effect of individual and spousal characteristics on the labour force participation of individuals living in elderly two-adult households. The comparative approach taken here studies men and women separately and uses the first eight waves (1994-2001) of the European Community Household Panel (ECHP). We compare results of three countries: Finland (a country with a high degree of women’s labour force participation), Belgium and Germany (countries where women’s labour force participation is relatively low). Results of multinomial logit model estimations suggest that are substantive differences between countries as well as between the behaviour of men and women across the various channels out of employment. We find evidence that a wife exerts a stronger influence on a husband’s retirement decision. One explanation for this may be found in asymmetric complementarities of leisure – a husband’s enjoyment of non-employment may depend much more on his wife also being non-employed than vice versa. There is evidence that the complementarities of leisure hypothesis dominates the hypothesis concerning the added worker (where the labour supply of one spouse increases when the other spouse’s income is reduced or disappears). These results are in line with evidence from the US and have some important implications: simulations of the effect of changes in the pension system on men’s retirement may yield incorrect answers if spillover effects are ignored
The Kaplan-Meier curves of cumulative incidences of in-hospital death between women and men.
No full textThe Kaplan-Meier curves of cumulative incidences of in-hospital death between women and men.</p
Evidence for universal earthquake rupture initiation behavior
No full textEarthquake onsets provide a unique opportunity to study physical rupture processes because they are more easily observable than later rupture stages. Despite this relative simplicity, the observational basis for rupture onsets is unclear. Numerous reports of evidence for magnitude-dependent rupture onsets (which imply deterministic rupture behavior, e.g. Colombelli et al., 2014) stand in contradiction to a large body of physics-based rupture modeling efforts, which are mostly based on inherently non-deterministic principles (e.g. Rice, 1993). Here we make use of the abundance of short-distance recordings available today; a magnitude-dependency of onsets should appear most prominently in such recordings. We use a simple method to demonstrate that all ruptures in the studied magnitude range (4 < M < 8) share a universal initial rupture behavior and discuss ensuing implications for physical rupture processes and earthquake early warning
- …
