100+ years of recomputed surface wave magnitude of shallow earthquakes

Among the multitude of magnitude scales developed to measure the size of an earthquake, the surface wave magnitude MS is the only magnitude type that can be computed since the dawn of modern observational seismology (beginning of the 20th century) for most shallow earthquakes worldwide. This is possible thanks to the work of station operators, analysts and researchers that performed measurements of surface wave amplitudes and periods on analogue instruments well before the development of recent digital seismological practice. As a result of a monumental undertaking to digitize such pre-1971 measurements from printed bulletins and integrate them in parametric data form into the database of the International Seismo- logical Centre (ISC, www.isc.ac.uk, last access: August 2021), we are able to recompute MS using a large set of stations and obtain it for the first time for several hundred earthquakes. We summarize the work started at the ISC in 2010 which aims to provide the seismological and broader geoscience community with a revised MS dataset (i.e., catalogue as well as the underlying station data) starting from December 1904 up to the last complete year reviewed by the ISC (currently 2018). This MS dataset is available at the ISC Dataset Repository at https://doi.org/10.31905/0N4HOS2D.

Magnitude Scales for Marsquakes Calibrated from InSight Data

ABSTRACT In preparation for the National Aeronautics and Space Administration Interior exploration using Seismic Investigations, Geodesy and Heat Transport (InSight) Discovery Program mission, Böse et al. (2018) calibrated magnitude scales for marsquakes that incorporated prelaunch knowledge of Mars’ interior structure and the expected ambient and instrumental noise. Now, using data collected during the first two years after the successful deployment of the InSight very-broadband seismometer on the Martian surface, we revise these relations to account for the seismic and noise characteristics observed on Mars. The data collected so far (until 12 October 2020) include 485 seismic event detections and suggest that (1) marsquakes are characterized by energy between ∼0.1 and 10 Hz; (2) whereas first arriving P- and S-wave phases are regularly identified and assigned, both surface waves and secondary phase arrivals are extremely challenging to identify; (3) the majority of identified events include a strong excitation of an unexpected 2.4 Hz ground resonance; and (4) so-called high-frequency (HF) events exist that are visible mainly as guided Pg/Sg wave trains. In view of these observations, we update our scaling relations for the spectral and body-wave magnitudes, Mw,specMa, mbMa, and mbSMa, and introduce a new magnitude scale, M2.4Ma, for HF events. We use these scales to determine that the magnitudes of events in the current InSight version 5 catalog range between 1.1 and 3.7, with event-specific uncertainties σM ranging from 0.2 to 0.4. Because of the currently unclear interpretation of HF events, magnitude estimates for these events primarily serve as a relative comparison.

Equivalent Hazard Magnitude Scale

Hazard magnitude scales are widely adopted to facilitate communication regarding hazard events and the corresponding decision making for emergency management. A hazard magnitude scale measures the strength of a hazard event considering the natural forcing phenomena and the severity of the event with respect to average entities at risk. However, existing hazard magnitude scales cannot be easily adapted for comparative analysis across different hazard types. Here, we propose an equivalent hazard magnitude scale, called the Gardoni Scale after Professor Paolo Gardoni, to measure hazard strength across multiple types of hazards. Using global historical records of hazard magnitude indicators and impacts of events of 12 hazard types from 1900 to 2020, we demonstrate that an equivalent hazard magnitude on the Gardoni Scale can be derived as correlated with the expectation of an impact metric of hazard event. In this study, we model the impact metric as a function of fatalities, total affected population, and total economic damage. Our results show that hazard magnitudes of events can be evaluated and compared across hazard types. For example, we find that tsunami and drought events tend to have large hazard magnitudes, while tornadoes are relatively small in terms of hazard magnitude. In addition, we demonstrate that the scale can be used to evaluate hazard equivalency of historical events. For example, we show that the hazard magnitude of the February 2021 North American cold wave event affecting the southern states of the United States of America was equivalent to the hazard magnitude of Hurricane Harvey in 2017 or a magnitude 7.5 earthquake. Future work will expand the current study in hazard equivalency to modelling of local intensities of hazard events and hazard conditions within a multi-hazard context.

Equivalent Hazard Magnitude Scale

Effective management of natural hazards requires the capability of cross-hazard evaluations. However, existing hazard magnitude scales cannot be easily adapted to evaluate sizes of events across different hazard types. Here, we propose a regression-based methodology with historical data on hazard impacts and magnitude indicators worldwide from 1900 to 2020 to derive an equivalent magnitude scale, called the Gardoni Scale after Professor Paolo Gardoni, to effectively quantify and compare sizes of events across twelve natural hazard types. Our results suggest that when compared on the Gardoni Scale, tsunami and drought disasters tend to have large magnitudes, while tornadoes are relatively small in size. We further propose hazard equivalency as a new area of research for cross-hazard evaluations of sizes and intensities of natural hazard events. Continuing efforts in this new area will strengthen guidance for resource allocation for hazard management, facilitate disaster communication, and enhance risk analysis within a multi-hazard context.

Erring Experts? A Critique of Wine Ratings as Hedonic Scaling

Consumers use expert ratings to help choose wine, and economists find correlations between ratings and transaction prices. Rating scales resemble hedonic scales in the behavioral sciences, which suffer from an “intersubjectivity” problem. Taste is a private sensation; people taste differently (an external validity problem), so ratings are often unreliable hedonic markers of enjoyment. But why? Hedonic measurements from food science (“general Labeled Magnitude Scales”) attempt to adjust for differences in perceived sensory sensitivity and offer clues. Resulting insights illustrate wine ratings’ shortcomings as reliable guides to enjoyment. (JEL Classifications: C14, D12, D91, L15, L66)

Harsh and Sweet Sensations Predict Acute Liking of Electronic Cigarettes, but Flavor Does Not Affect Acute Nicotine Intake: A Pilot Laboratory Study in Men

Introduction Electronic cigarette use is increasing in popularity, and thousands of flavors are available. Adolescent vaping rates in the United States have nearly doubled in the past year. Unlike combustible tobacco, added flavors are not currently regulated for some types of electronic cigarette products. Here, we investigated the role of flavor in electronic cigarette liking and acute intake. Methods Men (n = 39) aged 18–45 vaped in a controlled laboratory setting after being randomized to one of four e-liquids: 6 mg nicotine/mL cherry, 18 mg/mL cherry, 6 mg/mL chocolate, or 18 mg/mL chocolate. They completed several questionnaires, and vaped ad libitum for 10 minutes. After the first puff, participants rated sensations (sweetness, bitterness, coolness, harshness/irritation) on general labeled magnitude scales (gLMS) and rated overall liking on a generalized hedonic scale. Once the 10-minute session ended, participants made another set of ratings. Results Liking was generally stable across the vaping session and liking varied substantially across the four conditions. Across all conditions, sensory ratings predicted liking: harshness/irritation was negatively associated with first puff liking, whereas perceived sweetness was positively associated with first puff liking. First puff liking associated with increased amount of e-liquid vaped, but not total nicotine intake. Participants appeared to titrate their nicotine intake regardless of assigned condition. Conclusion Flavored e-liquids affect acute liking ratings, but not acute nicotine intake. Implications These data suggest individuals who regularly vape may titrate their nicotine intake, regardless of flavor, and contrary to expectations, acute liking did not predict total nicotine intake. However, more-liked flavors may potentially make higher nicotine levels more tolerable by adding pleasant sensations directly, rather than by perceptual masking that reduces aversive sensations.

Gutenberg-Richter b value studies along the Mexican Subduction Zone and data constraints

The Gutenberg-Richter b value is one of the most important tools for seismic hazard studies; this value is most useful in estimating seismicity rates, and also is related to ambient stress levels and shows changes precursory to the occurrence of large earthquakes. However, correct and reliable determinations of the b value are critically dependent on having adequate data samples. Studies oriented to corroborate whether precursory changes in the b value occur before large (M ? 7.0) along the Mexican subduction zone, were done based on data from the Servicio Sismológico Nacional (SSN, Mexico’s National Seismological Service) seismic catalog, from 1988 to 2018. Results for five earthquakes are suggestive that precursory changes may occur, but differences between measured values are not significant because of large uncertainties due to the SSN using different magnitude scales for small (below M ~4.5) and medium to large (above M ~4.5) magnitudes. We submit that until an appropriate scale is implemented for small magnitudes, results from b-value studies based on SSN data should be considered critically.

Regional Earthquake Magnitude Conversion Relations for the Himalayan Seismic Belt

We present regional earthquake magnitude conversion relations among different magnitude scales (Mw, Ms, mb, ML, and MD) for the Himalayan seismic belt developed from data of local, regional, and international seismological agencies (International Seismological Centre [ISC], National Earthquake Information Centre [NEIC], Global Centroid Moment Tensor Solution [CMT], International Data Centre [IDC], China Earthquake Administration [BJI], and National Centre for Seismology [NDI]). The intra- (within the same magnitude scale) and inter- (with different magnitude scales) magnitude regression relations have been established using the general orthogonal regression and orthogonal distance regression techniques. Results show that the intra-magnitude relations for Mw, Ms, and mb reported by the Global CMT, ISC, and NEIC exhibit 1:1 relationships, whereas ML reported by the IDC, BJI, and NDI deviates from this relationship. The IDC underestimates Ms and mb compared with the ISC, NEIC, and Global CMT; this may be due to different measurement procedures adopted by the IDC agency. The inter-magnitude relations are established between Mw,Global CMT and Ms, mb, and ML reported by the ISC, NEIC, IDC, and NDI, and compared with the previously developed regional and global regression relations. The duration (MD) and local (ML) magnitudes reported by NDI exhibit a 1:1 relationship. The derived magnitude regression relations are expected to support the homogenization of the earthquake catalogs and to improve seismic hazard assessment in this region.

Fuzzy Expert System for Earthquake Prediction in Western Himalayan Range

Fuzzy Expert System (FES) with application to earthquake prediction has been presented to reproduce the performance of a human expert in earthquake prediction using expert systems. This research aims to predict future earthquakes having a magnitude 5.5 or greater. Previous earthquake data from 2000 to 2019 have been collected for this purpose. Since the earthquake data for the specified region have been reported on different magnitude scales, suitable relationships were determined to obtain uniform data. The uniform data have been used to calculate seismicity indicators according to the guidelines provided by Gutenberg-Richter’s scale for quantitative determination of earthquake features. The relationships among these seismic indicators have been used by the human expert to set the rule base of Fuzzy expert system. These rules have been mathematically validated and tested on instrumentally recorded earthquake data. The results obtained from the proposed FES presented 47 % accuracy in predicting future earthquakes that may occur in the 100 km radial area from 34.708 ° N, 72.5478 ° E.

Discrimination of Isointense Bitter Stimuli in a Beer Model System

Prior work suggests humans can differentiate between bitter stimuli in water. Here, we describe three experiments that test whether beer consumers can discriminate between different bitterants in beer. In Experiment 1 (n = 51), stimuli were intensity matched; Experiments 2 and 3 were a difference from control (DFC)/check-all-that-apply (CATA) test (n = 62), and an affective test (n = 81). All used a commercial non-alcoholic beer spiked with Isolone (a hop extract), quinine sulfate dihydrate, and sucrose octaacetate (SOA). In Experiment 1, participants rated intensities on general labeled magnitude scales (gLMS), which were analyzed via ANOVA. In Experiment 2, participants rated how different samples were from a reference of Isolone on a 7-point DFC scale, and endorsed 13 attributes in a CATA task. DFC data were analyzed via ANOVA with Dunnett’s test to compare differences relative to a blind reference, and CATA data were analyzed via Cochran’s Q test. In Experiment 3, liking was assessed on labeled affective magnitude scales, and samples were also ranked. Liking was analyzed via ANOVA and rankings were analyzed with a Cochran–Mantel–Haenszel test. Experiment 1 confirmed that samples were isointense. In Experiment 2, despite being isointense, both quinine (p = 0.04) and SOA (p = 0.03) were different from Isolone, but no significant effects were found for CATA descriptors (all p values > 0.16). In Experiment 3, neither liking (p = 0.16) or ranking (p = 0.49) differed. Collectively, these data confirm that individuals can discriminate perceptually distinct bitter stimuli in beer, as shown previously in water, but these differences cannot be described semantically, and they do not seem to influence hedonic assessments.