Magnitude Conversion Research Articles

DeepPipe: A Multi-Stage Knowledge-Enhanced Physics-Informed Neural Network for Hydraulic Transient Simulation of Multi-Product Pipeline

In the chemical pipelining industry, owing to the high-pressure transportation process, an accurate hydraulic transient simulation tool plays a central role in preventing the slack line flow and overpressure from causing pipeline operation treacherous. Nevertheless, the current model-driven method often faces challenges in balancing computational efficiency with accuracy, and the existing data-driven models struggle to produce explainable results from the physics perspectives since insufficient theoretical principles are incorporated into the model training. Additionally, the existing physics-informed learning architecture fails to achieve a gradient-balanced training, resulting from the significant magnitude difference in outputs and multiple loss terms. Consequently, a Multi-Stage Knowledge-Enhanced Physics-Informed Neural Network (MS-KE-PINN) is proposed for the hydraulic transient simulation of multi-product pipelines. To enforce the neural network producing simulation results with high consistency to physical laws, the governing equations, boundary, and initial condition are incorporated into the training process for an efficient mesh-free simulation. Then, considering that the significant magnitude difference between outputs can easily lead to deficient performance in the gradient descent, the magnitude conversion on the outputs and the equivalent conversion of the governing equations are implemented to enhance the training effect of the neural network. Subsequently, to tackle the imbalanced gradient of multiple loss terms with fixed weights, a multi-stage hierarchical training strategy is designed to improve the approximation capacity of the neural network. Numerical simulation cases demonstrate a better approximation function of the proposed model than the state-of-art models, while the mean absolute percentage errors yielded by MS-KE-PINN are reduced by 77.4 %, 88.7 %, and 87.8 % in three simulation operation conditions for pressure prediction. Furthermore, experimental investigations from a real-world multi-product pipeline suggest that the proposed model can still draw accurate simulation results even under complex and dynamic hydraulic transient scenarios in practice, with root mean squared errors reduced by 94.8 % and 80 % than that of the physics-informed neural network. To this end, the proposed model can conduct accurate and effective hydraulic transient analysis, thus ensuring the safe operation of the pipeline.

Identification of the active faults and seismotectonic zonation of Laos territory

In this study, the main active faults in the territory of Laos were identified by analyzing the spatial relationship between the distributions of neo-tectonic faults and earthquake epicenters. The map of neo-tectonic faults was built by integrating the results of neo-tectonic faults research using geological-geomorphological data together with the lineament map obtained from remote sensing analysis. Nontectonic lineaments were eliminated by correlating the spatial distribution of the lineament field with a topographic map, DEM, and geological-geomorphological data. The earthquake data, including 4416 events in Laos and its surroundings, were collected from different sources: the International Seismological Center (ISC), the earthquakes recorded by the local seismic network in Laos, the seismic data in Vietnam, and the earthquake catalog provided by the Thailand Meteorological Department (TMD). Among these, 820 events were located using the hypocenter method, and the local network recorded the data. The magnitude conversion was applied to get a unified scale Mw. The catalog of 1617 main shocks obtained after eliminating foreshocks and aftershocks using the declustering technique was used for a spatial correlation with the neotectonic fault distribution to identify active faults. A total of 14 main active fault zones in the Laos territory were defined. Most are also seismogenic faults with Mw ≥ 5.0 occurring along their trace. Considering the characteristics of seismic activity and the active and neotectonic faults, the territory of Laos can be divided into six seismotectonic zones according to the decreasing level of seismic activity: the Western, the Northeastern Samnua, the Phongsali, the South Truong Son, the North Truong Son, and the Khorat zones. Each zone is characterized by relative homogeneity in the seismic activity and the characteristics of active and neotectonic faults.

Integrated study on buried pipelines, co-seismic landslides, and magnitude conversion for 2023 Türkiye earthquake

Türkiye is known for its intricate tectonic structure and high seismic activity, which makes in-depth research on earthquakes necessary. This research paper presents a multifaceted examination of earthquake impact in Türkiye, encompassing critical elements of seismic vulnerability with a special focus on the latest twin earthquake of February 6, 2023. Firstly, a three-dimensional finite element (FE) analysis has been conducted to explore the buried pipeline behavior under left-lateral strike-slip faults. Secondly, making use of the earthquake data from 1976 to 2023, a new Newmark displacement-based model has been proposed which predicts co-seismic landslide displacement. Finally, new magnitude conversion relations are developed in the generalized moment magnitude scale (Mwg) for Türkiye using three statistical regression techniques. The maximum tensile strain was found to be around 2.0% based on the findings of the 3D numerical study of an underground pipe that was subjected to left-lateral strike-slip fault movement. The proposed co-seismic landslide displacement model was developed based on moment magnitude, yield acceleration, and peak ground acceleration, which yields an R-squared value of 0.93. Outcomes of the magnitude conversion study depicted that the improved general orthogonal regression (IGOR) relationships developed in this study performed better than the other conventional methods of regression. Also, the proposed regional relations based on Mwg scale perform better than global relations as they provide closer values to the observed ones. By offering a comprehensive perspective on seismic impact, the research lays the groundwork for upgraded predictive methods and refined seismic design considerations. The proposed models and conversion relations contribute to the strengthening of critical infrastructures, providing a forward-looking approach to enhance preparedness and resilience against earthquake disasters in Türkiye.

Virial Black Hole Masses for Active Galactic Nuclei behind the Magellanic Clouds

We use the spectroscopic data collected by the Magellanic Quasars Survey (MQS) and the photometric V- and I-band data from the Optical Gravitational Lensing Experiment (OGLE) to measure the physical parameters for active galactic nuclei (AGNs) located behind the Magellanic Clouds. The flux-uncalibrated MQS spectra were obtained with the 4 m Anglo-Australian Telescope and the AAOmega spectroscope (R = 1300) in a typical ∼1.5 hr visit. They span a spectral range of 3700–8500 Å and have signal-to-noise ratios in a range of 3–300. We report the discovery and observational properties of 161 AGNs in this footprint, which expands the total number of spectroscopically confirmed AGNs by MQS to 919. After the conversion of the OGLE mean magnitudes to the monochromatic luminosities at 5100, 3000, and 1350 Å, we were able to reliably measure the black hole masses for 165 out of 919 AGNs. The remaining physical parameters we provide are the bolometric luminosities and the Eddington ratios. A fraction of these AGNs have been observed by the OGLE survey since 1997 (all of them since 2001), enabling studies of correlations between the variability and physical parameters of these AGNs.

Homogenizing instrumental earthquake catalogs – a case study around the Dead Sea Transform Fault Zone

The creation of a homogenized earthquake catalog is a fundamental step in seismic hazard analysis. The homogenization procedure, however, is complex and requires a good understanding of the heterogeneities among the available bulletins. Common events within the bulletins have to be identified and assigned with the most suitable origin time and location solution, while all the events have to be harmonized into a single magnitude scale. This process entails several decision variables that are usually defined using qualitative measures or expert opinion, without a clear exploration of the associated uncertainties. To address this issue, we present an automated and data-driven workflow that defines spatio-temporal margins within which duplicate events fall and converts the various reported magnitudes into a common scale. Special attention has been paid to the fitted functional form and the validity range of the derived magnitude conversion relations. The proposed methodology has been successfully applied to a wide region around the Dead Sea Transform Fault Zone (27N-36N, 31E-39E), with input data from various sources such as the International Seismological Centre and the Geophysical Institute of Israel. The produced public catalog contains more than 5500 events, between 1900 and 2017, with moment magnitude Mw above 3. The MATLAB/Python scripts used in this study are also available.

Homogenization of magnitudes of the ISC Bulletin

SUMMARY We implemented an automatic procedure to download the hypocentral data of the online Bulletin of the International Seismological Centre (ISC) in order to produce in near real-time a homogeneous catalogue of the Global and EuroMediterranean instrumental seismicity to be used for forecasting experiments and other statistical analyses. For the interval covered by the reviewed ISC Bulletin, we adopt the ISC locations and convert the surface wave magnitude (Ms) and short-period body-wave magnitude (mb) as computed by the ISC to moment magnitude (Mw), using empirical relations. We merge the so obtained proxies with real Mw provided by global and EuroMediterranean moment tensor catalogues. For the most recent time interval (about 2 yr) for which the reviewed ISC Bulletin is not available, we do the same but using the preferred (prime) location provided by the ISC Bulletin and converting to Mw the Ms and mb provided by some authoritative agencies. For computing magnitude conversion equations, we use curvilinear relations defined in a previous work and the chi-square regression method that accounts for the uncertainties of both x and y variables.

A monosurfactant-stabilized dual-responsive and versatile emulsion lubricant

Emulsions consisting of lubricating base oil and water have extensive applications in the fields of metalworking and heavy-duty machinery. Due to the compositional complexity that confines an effective recycling of emulsion constituents and the frequent use of toxic, non-biodegradable mineral base oil, an industrial emulsion lubricant is usually easy to produce severe environmental burdens and health issues. Here we report a dual-responsive and versatile lubricating emulsion solely consisting of water, an eco-friendly ester base oil and a synthetic cationic emulsifier. Taking advantage of the inclusion of azobenzene moiety, [CeCl3Br]- anion and methylimidazole head-group, the surfactant can not only undergo tribochemical reactions to function as a lubricant additive to achieve very low interfacial friction, but also endow the resulting emulsion efficient anticorrosion, antibiosis and both light- and magneto-responsiveness. Based on a reversibly photo-triggered variation in the hydrophobicity of surfactant, an on-demand separation and recycling of emulsion component followed by a nearly one order of magnitude conversion in the friction can be realized. Together with its magneto-controlled migration and adaptivity to high normal loads, we envision that the emulsion lubricant may find potential applications in a broad range of industrial systems requiring lubrication and heat dissipation as well as smart devices needing control over the friction between two contacting surfaces.

Regression relationships for conversion of body wave and surface wave magnitudes toward Das magnitude scale, Mwg

A reliable and standardized estimation of earthquake size is a fundamental requirement for all tectonophysical and engineering applications. Several investigations raised questions about the determinations of smaller and intermediate earthquakes using Mw scale. Recent investigations (Das et al. in Bull Seismol Soc Am 108(4):1995–2007, 2018b) show that the moment magnitude scale Mw is not applicable for lower and intermediate ranges throughout the world and does not efficiently represent the seismic source potential due to its dependence on surface wave magnitudes; therefore, an observed seismic moment (M0)-based magnitude scale, Mwg, which smoothly connects seismic source processes and highly correlates with seismic-radiated energy (Es) compared to the Mw scale is suggested. With the goal of constructing a homogeneous data set of Mwg to be used for earthquake-related studies, relationships for body wave (mb) and surface wave magnitudes (Ms) toward Mwg have been developed using regression methodologies such as generalized orthogonal regression (GOR) (GOR1: GOR relation is expressed in terms of the observed independent variable; and GOR2: GOR relation is used inappropriately in terms of theoretical true point of GOR line) and standard least-square regression (SLR). In order to establish regression relationships, global data have been considered during 1976–2014 for mb magnitudes of 524,790 events from the International Seismological Centre (ISC) and 326,201 events from the National Earthquake Information Center (NEIC), Ms magnitudes of 111,443 events from ISC along with 41,810 Mwg events data from the Global Centroid Moment Tensor (GCMT). Scaling relationships have been obtained between mb and Mwg for magnitude range 4.5 ≤ mb ≤ 6.2 for ISC and NEIC events using GOR1, GOR2 and SLR methodologies. Furthermore, scaling relationships between Ms and Mwg have been obtained for magnitude ranges 3.0 ≤ Ms ≤ 6.1 and 6.2 ≤ Ms ≤ 8.4 using GOR1, GOR2 and SLR procedures. Our analysis found that GOR1 provides improved estimates of dependent variable compared to GOR2 and SLR on the basis of statistical parameters (mainly uncertainty on slope and intercept, RMSE and Rxy) as reported in Das et al. (2018b). The derived global scaling relationships would be helpful for various seismological applications such as seismicity, seismic hazard and Risk assessment studies.

Comment on “Earthquake Magnitude Conversion Problem” by Ranjit Das, H. R. Wason, Gabriel Gonzalez, M. L. Sharma, Deepankar Choudhury, Conrad Lindholm, Narayan Roy, and Pablo Salazar

Article Commentary| March 01, 2023 Comment on “Earthquake Magnitude Conversion Problem” by Ranjit Das, H. R. Wason, Gabriel Gonzalez, M. L. Sharma, Deepankar Choudhury, Conrad Lindholm, Narayan Roy, and Pablo Salazar Paolo Gasperini; Paolo Gasperini * 1Dipartimento di Fisica e Astronomia, Università di Bologna, Bologna, Italy2Istituto Nazionale di Geofisica e Vulcanologia, Bologna, Italy *Corresponding author: paolo.gasperini@unibo.it https://orcid.org/0000-0002-5314-0563 Search for other works by this author on: GSW Google Scholar Barbara Lolli; Barbara Lolli 2Istituto Nazionale di Geofisica e Vulcanologia, Bologna, Italy https://orcid.org/0000-0003-4186-9055 Search for other works by this author on: GSW Google Scholar Silvia Castellaro Silvia Castellaro 1Dipartimento di Fisica e Astronomia, Università di Bologna, Bologna, Italy https://orcid.org/0000-0001-7714-7041 Search for other works by this author on: GSW Google Scholar Author and Article Information Paolo Gasperini https://orcid.org/0000-0002-5314-0563 * 1Dipartimento di Fisica e Astronomia, Università di Bologna, Bologna, Italy2Istituto Nazionale di Geofisica e Vulcanologia, Bologna, Italy Barbara Lolli https://orcid.org/0000-0003-4186-9055 2Istituto Nazionale di Geofisica e Vulcanologia, Bologna, Italy Silvia Castellaro https://orcid.org/0000-0001-7714-7041 1Dipartimento di Fisica e Astronomia, Università di Bologna, Bologna, Italy *Corresponding author: paolo.gasperini@unibo.it Publisher: Seismological Society of America First Online: 01 Mar 2023 Online ISSN: 1943-3573 Print ISSN: 0037-1106 © Seismological Society of America Bulletin of the Seismological Society of America (2023) https://doi.org/10.1785/0120180243 Article history First Online: 01 Mar 2023 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Paolo Gasperini, Barbara Lolli, Silvia Castellaro; Comment on “Earthquake Magnitude Conversion Problem” by Ranjit Das, H. R. Wason, Gabriel Gonzalez, M. L. Sharma, Deepankar Choudhury, Conrad Lindholm, Narayan Roy, and Pablo Salazar. Bulletin of the Seismological Society of America 2023; doi: https://doi.org/10.1785/0120180243 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyBulletin of the Seismological Society of America Search Advanced Search Similar to the previous ones, the latest paper by Das and Colleagues (Das et al., 2018) on the application of the general orthogonal regression (GOR) method (Fuller, 1987; Castellaro et al., 2006), for the conversions between different types of earthquake magnitudes, is a collection of incorrect or undemonstrated assertions, most of which have already been pointed out in several contributions that have been published in the last few years (Gasperini and Lolli, 2014a, b; Gasperini et al., 2015, 2018; Pujol, 2018). We recall below only some... You do not have access to this content, please speak to your institutional administrator if you feel you should have access.

Comments on “Unbiased Estimation of Moment Magnitude from Body- and Surface-Wave Magnitudes,” by R. Das, H. Wason, and M. Sharma and “Earthquake Magnitude Conversion Problem” by R. Das, H. Wason, G. Gonzalez, M. Sharma, D. Choudhury, C. Lindholm, N. Roy, and P. Salazar

Article Commentary| March 01, 2023 Comments on “Unbiased Estimation of Moment Magnitude from Body‐ and Surface‐Wave Magnitudes,” by R. Das, H. Wason, and M. Sharma and “Earthquake Magnitude Conversion Problem” by R. Das, H. Wason, G. Gonzalez, M. Sharma, D. Choudhury, C. Lindholm, N. Roy, and P. Salazar Jose Pujol Jose Pujol * 1Department of Earth Sciences, University of Memphis, Memphis, Tennessee, U.S.A. *Corresponding author: jpujol@memphis.edu Search for other works by this author on: GSW Google Scholar Author and Article Information Jose Pujol * 1Department of Earth Sciences, University of Memphis, Memphis, Tennessee, U.S.A. *Corresponding author: jpujol@memphis.edu Publisher: Seismological Society of America First Online: 01 Mar 2023 Online ISSN: 1943-3573 Print ISSN: 0037-1106 © Seismological Society of America Bulletin of the Seismological Society of America (2023) https://doi.org/10.1785/0120180198 Article history First Online: 01 Mar 2023 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Jose Pujol; Comments on “Unbiased Estimation of Moment Magnitude from Body‐ and Surface‐Wave Magnitudes,” by R. Das, H. Wason, and M. Sharma and “Earthquake Magnitude Conversion Problem” by R. Das, H. Wason, G. Gonzalez, M. Sharma, D. Choudhury, C. Lindholm, N. Roy, and P. Salazar. Bulletin of the Seismological Society of America 2023; doi: https://doi.org/10.1785/0120180198 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyBulletin of the Seismological Society of America Search Advanced Search The conversion between two sets of different types of magnitudes is frequently carried out using a linear regression approach that takes into account the error in both variables. Once a linear relation has been derived, the following question arises: given a new value of one of the magnitudes, what value should be assigned to the other magnitude? This is a prediction problem, and the standard approach to solve it is to insert the new value in the linear relation, ignoring the fact that the new value may be affected by error. This approach was questioned by Das et al. (2014)... You do not have access to this content, please speak to your institutional administrator if you feel you should have access.

Magnitude relations between the teleseismic mb, the regional mR and Mw for intraplate earthquakes in Brazil

Magnitude conversions between different scales are important for comparison of seismic activity between different regions, homogenization of earthquake catalogs for seismic hazard calculations, and use of ground motion relations derived from other regions. Despite the trend of adopting Mw as the standard, reference magnitude scale, other scales are still much used for practical reasons and ease of calculation, such as the local ML for events detected by local networks, and short-period teleseismic mb for events in worldwide catalogues. In Brazil, a regional magnitude (mR), based on the maximum amplitude in the whole P-wave train recorded between 200 and 1500 km distance, has been adopted in our catalogues. The regional magnitude is equivalent to the teleseismic mb from 3.5 to 5.5.Empirical relations between the regional (mR), the teleseismic (mb) and the moment (Mw) magnitudes were determined for Brazilian intraplate earthquakes. Mw can be estimated from m by Mw = 1.10 m - 0.69. In this empirical relation, “m" is mb, mR, or the average of the two. However, despite the average consistency of the regional (mR) and teleseismic (mb) scales, it has been found that difference between mb and mR depend on the type of faulting mechanism: mb > mR for dip-slip earthquakes (reverse and normal faulting), and mb < mR for strike-slip events. This can be explained by the differences in the average radiation patterns of upper crustal earthquakes recorded at regional distances (more horizontally oriented take-off angles) or at teleseismic distances (more vertically oriented take-off angles). This brings the possibility to use the difference between regional and teleseismic magnitudes to indicate the probable type of focal mechanism.

Bring Back Systematic Broadband Surface-Wave Magnitude Practice

Editorial| May 13, 2022 Bring Back Systematic Broadband Surface‐Wave Magnitude Practice Domenico Di Giacomo Domenico Di Giacomo * 1International Seismological Centre, Pipers Lane, Thatcham, Berkshire, United Kingdom *Corresponding author: domenico@isc.ac.uk https://orcid.org/0000-0001-8472-8979 Search for other works by this author on: GSW Google Scholar Seismological Research Letters (2022) 93 (5): 2413–2417. https://doi.org/10.1785/0220220094 Article history first online: 13 May 2022 Cite View This Citation Add to Citation Manager Share Icon Share Twitter LinkedIn Tools Icon Tools Get Permissions Search Site Citation Domenico Di Giacomo; Bring Back Systematic Broadband Surface‐Wave Magnitude Practice. Seismological Research Letters 2022;; 93 (5): 2413–2417. doi: https://doi.org/10.1785/0220220094 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietySeismological Research Letters Search Advanced Search Seismologists often use the surface‐wave magnitude Ms (Gutenberg, 1945) to estimate the size of an earthquake and as basis for different types of seismological studies. Those include, among others, earthquake catalogs (e.g., Abe, 1981; Pacheco and Sykes, 1992), magnitude conversion relationships (e.g., Ekström and Dziewonski, 1988; Scordilis, 2006), and tsunami earthquakes (Kanamori, 1972; Jia et al., 2022). The computation of Ms is relatively simple because it is based on the measurement of the amplitude and period of surface waves generated by shallow earthquakes (usually considered as such if... You do not have access to this content, please speak to your institutional administrator if you feel you should have access.

Production of a homogeneous seismic catalog based on machine learning for northeast Egypt

Abstract This research presents a new approach which addresses the conversion of earthquake magnitude as a supervised machine-learning problem through a multistage approach. First, the moment magnitude (M w) calculations were extended to lower magnitude earthquakes using the spectral P-wave analyses of the vertical component seismograms to improve the scaling relation of M w and the local magnitude (M L) of 138 earthquakes in northeastern Egypt. Second, using unsupervised clustering and regression analysis, we applied the k-means clustering technique to subdivide the mapped area into multiple seismic activity zones. This clustering phase created five spatially close seismic areas for training regression algorithms. Supervised regression analysis of each seismic area was simpler and more accurate. Conversion relations between M w and M L were calculated by linear regression, general orthogonal regression (GOR), and random sample consensus (RANSAC) regression techniques. RANSAC and GOR produced better results than linear regression, which provides evidence for the effects of outliers on regression accuracy. Moreover, the overall multistage hybrid approach produced substantial improvements in the measured-predicted dataset residuals when individual seismic zones rather than all datasets were considered. In 90% of the analyzed cases, M w values could be regarded as M L values within 0.2 magnitude units. Moreover, predicted magnitude conversion relations in the current study corresponded well to magnitude conversion relations in other seismogenic areas of Egypt.

Regional Earthquake Magnitude Conversion Relations for the Himalayan Seismic Belt

AbstractWe 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.

The Homogenized Instrumental Seismic Catalog (HORUS) of Italy from 1960 to Present

AbstractWe implemented an automatic procedure to update in near-real time (daily to hourly) a homogeneous catalog of Italian instrumental seismicity to be used for forecasting experiments and other statistical analyses. The magnitudes of all events are homogeneously revalued to be consistent with Mw standard estimates made by the Global Centroid Moment Tensor project. For the time interval from 1960 to 15 April 2005, catalogs and online resources available for the Italian area were merged and all magnitudes were homogenized to Mw according to empirical relationships computed using the chi-square regression method, which properly consider the uncertainties of both variables. From 16 April 2005 to the present, an automatic procedure periodically downloads the data of the online bulletin of the Istituto Nazionale di Geofisica e Vulcanologia and of online moment tensor catalogs from respective websites, merges the different sources, and applies traditional magnitude conversions to Mw. The final catalog is provided on a website for public dissemination.

Seismic magnitude conversion and its effect on seismic hazard analysis

The aim of this study is to demonstrate the bias created in the seismic hazard studies due to the choice of magnitude scaling equations without any statistical basis. The earthquake catalogue of Tripura, India, has been used for the purpose of this study. The catalogue was homogenized using the various scaling equations suitable for the region. Then, the bias created on parameters, like the magnitude of completeness (Mc), a and b values of the Gutenberg–Richter recurrence relation, maximum magnitude (Mmax), and peak ground acceleration, was demonstrated. The standard deviations of Mc, a, and b parameters were observed to be 0.23, 0.27, and 0.037 respectively. The maximum variations in the Mmax and ground motion estimates were found to be 0.7 magnitude units and 0.2 g respectively. Then, the robustness of the regional rupture characters in overcoming the observed variations has been demonstrated. The trend of the rupture behavior of the seismic sources seems to be unaffected by the change in the magnitude scaling equations. The Mmax calculated from the rupture-based procedure was observed to be higher than that calculated from the probabilistic method. This variation in Mmax estimation has been utilized to critically assess the suitability of the magnitude scaling equations for the particular study area.

Low-complex processing element architecture for successive cancellation decoder

A low-complexity design architecture for implementing the Successive Cancellation (SC) decoding algorithm for polar codes is presented. Hardware design of polar decoders is accomplished using SC decoding due to the reduced intricacy of the algorithm. Merged processing element (MPE) block is the primary area occupying factor of the SC decoder as it incorporates numerous sign and magnitude conversions. Two’s complement method is typically used in the MPE block of SC decoder. In this paper, a low-complex MPE architecture with minimal two’s complement conversion is proposed. A reformulation is also applied to the merged processing elements at the final stage of SC decoder to generate two output bits at a time. The proposed merged processing element thereby reduces the hardware complexity of the SC decoder and also reduces latency by an average of 64%. An SC decoder with code length 1024 and code rate 1/2 was designed and synthesized using 45-nm CMOS technology. The implementation results of the proposed decoder display significant improvement in the Technology Scaled Normalized Throughput (TSNT) value and an average 48% reduction in hardware complexity compared to the prevalent SC decoder architectures. Compared to the conventional SC decoder, the presented method displayed a 23% reduction in area.

Comment on “Unbiased Estimation of Moment Magnitude from Body‐ and Surface‐Wave Magnitudes,” by R. Das, H. R. Wason, and M. L. Sharma, and “Comparative Analysis of Regression Methods Used for Seismic Magnitude Conversions” by P. Gasperini, B. Lolli, and S. Castellaro

Article Commentary| November 14, 2017 Comment on “Unbiased Estimation of Moment Magnitude from Body‐ and Surface‐Wave Magnitudes,” by R. Das, H. R. Wason, and M. L. Sharma, and “Comparative Analysis of Regression Methods Used for Seismic Magnitude Conversions” by P. Gasperini, B. Lolli, and S. Castellaro J. Pujol J. Pujol Search for other works by this author on: GSW Google Scholar Author and Article Information J. Pujol Publisher: Seismological Society of America First Online: 14 Nov 2017 Online Issn: 1943-3573 Print Issn: 0037-1106 © Seismological Society of America Bulletin of the Seismological Society of America (2018) 108 (1): 533–539. https://doi.org/10.1785/0120160176 Article history First Online: 14 Nov 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation J. Pujol; Comment on “Unbiased Estimation of Moment Magnitude from Body‐ and Surface‐Wave Magnitudes,” by R. Das, H. R. Wason, and M. L. Sharma, and “Comparative Analysis of Regression Methods Used for Seismic Magnitude Conversions” by P. Gasperini, B. Lolli, and S. Castellaro. Bulletin of the Seismological Society of America 2017;; 108 (1): 533–539. doi: https://doi.org/10.1785/0120160176 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyBulletin of the Seismological Society of America Search Advanced Search Because the conversion between different types of magnitudes is frequently an essential component to seismotectonic and seismic hazard studies, it is important to understand the advantages and limitations of different conversion methods that have been proposed in the literature. In fact, there is an aspect of the conversion that is the matter of current debate, which can be summarized as follows. Given two sets of different types of magnitudes, the conversion generally takes the form of a linear relation between the two magnitudes. As both magnitudes are affected by errors, this relation is obtained using regression techniques that take into... You do not have access to this content, please speak to your institutional administrator if you feel you should have access.

Reply to “Comment on ‘Unbiased Estimation of Moment Magnitude from Body‐ and Surface‐Wave Magnitudes’ by R. Das, H. R. Wason, and M. L. Sharma and ‘Comparative Analysis of Regression Methods Used for Seismic Magnitude Conversions’ by P. Gasperini, B. Lolli, and S. Castellaro” by J. Pujol

Reply to “Comment on ‘Unbiased Estimation of Moment Magnitude from Body‐ and Surface‐Wave Magnitudes’ by R. Das, H. R. Wason, and M. L. Sharma and ‘Comparative Analysis of Regression Methods Used for Seismic Magnitude Conversions’ by P. Gasperini, B. Lolli, and S. Castellaro” by J. Pujol

Magnitude Conversion of Earthquake Rate Forecasts

Magnitude Conversion of Earthquake Rate Forecasts