Local Catalog Research Articles

Improving back projection imaging with a novel physics‐based aftershock calibration approach: A case study of the 2015 Gorkha earthquake

AbstractThe 2015 Mw 7.8 Nepal‐Gorkha earthquake with casualties of over 9000 people was the most devastating disaster to strike Nepal since the 1934 Nepal‐Bihar earthquake. Its rupture process was imaged by teleseismic back projections (BP) of seismograms recorded by three, large regional networks in Australia, North America, and Europe. The source images of all three arrays reveal a unilateral eastward rupture; however, the propagation directions and speeds differ significantly between the arrays. To understand the spatial uncertainties of the BP analyses, we analyze four moderate size aftershocks recorded by all three arrays exactly as had been conducted for the main shock. The apparent source locations inferred from BPs are systematically biased from the catalog locations, as a result of a slowness error caused by three‐dimensional Earth structures. We introduce a physics‐based slowness correction that successfully mitigates the source location discrepancies among the arrays. Our calibrated BPs are found to be mutually consistent and reveal a unilateral rupture propagating eastward at a speed of 2.7 km/s, localized in a relatively narrow and deep swath along the downdip edge of the locked Himalayan thrust zone. We find that the 2015 Gorkha earthquake was a localized rupture that failed to break the entire Himalayan décollement to the surface, which can be regarded as an intermediate event during the interseismic period of larger Himalayan ruptures that break the whole seismogenic zone width. Thus, our physics‐based slowness correction is an important technical improvement of BP, mitigating spatial uncertainties and improving the robustness of single and multiarray studies.

Differences in Epicentral Location of Mexican Earthquakes between Local and Global Catalogs: An update

Differences in epicentral locations between local and global catalogs for earthquakes in the Mexican subduction zone were first observed to be biased in the 1980s, based on a few well studied events. In this study we compare locations between two local catalogs; (1) a recent high precision catalog of events in the state of Guerrero and (2) the catalog of the Servicio Sismológico Nacional (SSN), to the global catalog of the United States Geological Service (USGS). We find that on average epicentral locations in the global catalog of earthquakes larger than M 5 in the Mexican subduction zone are 26 km towards N54°E of those in the local catalogs. We investigate how the errors vary for different types of earthquakes in Guerrero, and how they vary along the trench, from the state of Jalisco to the state of Chiapas. The average differences are largest for thrust events occurring close to the trench, and for events in Michoacán. The differences are greater on average for large earthquakes than for small. There is a trade-off between the distance from the trench and timing, suggesting a poor resolution of these parameters, due to the lack of stations the Pacific Ocean. We attribute the differences in locations to systematic patterns in the velocity structure of the mantle, with consistently fast paths to the northeast and relatively slow paths towards the southwest.

Condensation of earthquake location distributions: Optimal spatial information encoding and application to multifractal analysis of south Californian seismicity.

We present the "condensation" method that exploits the heterogeneity of the probability distribution functions (PDFs) of event locations to improve the spatial information content of seismic catalogs. As its name indicates, the condensation method reduces the size of seismic catalogs while improving the access to the spatial information content of seismic catalogs. The PDFs of events are first ranked by decreasing location errors and then successively condensed onto better located and lower variance event PDFs. The obtained condensed catalog differs from the initial catalog by attributing different weights to each event, the set of weights providing an optimal spatial representation with respect to the spatially varying location capability of the seismic network. Synthetic tests on fractal distributions perturbed with realistic location errors show that condensation improves spatial information content of the original catalog, which is quantified by the likelihood gain per event. Applied to Southern California seismicity, the new condensed catalog highlights major mapped fault traces and reveals possible additional structures while reducing the catalog length by ∼25%. The condensation method allows us to account for location error information within a point based spatial analysis. We demonstrate this by comparing the multifractal properties of the condensed catalog locations with those of the original catalog. We evidence different spatial scaling regimes characterized by distinct multifractal spectra and separated by transition scales. We interpret the upper scale as to agree with the thickness of the brittle crust, while the lower scale (2.5 km) might depend on the relocation procedure. Accounting for these new results, the epidemic type aftershock model formulation suggests that, contrary to previous studies, large earthquakes dominate the earthquake triggering process. This implies that the limited capability of detecting small magnitude events cannot be used to argue that earthquakes are unpredictable in general.

Star formation rates in isolated galaxies selected from the Two-Micron All-Sky Survey

We have considered the star formation properties of 1616 isolated galaxies from the 2MASS XSC selected sample (2MIG) with the FUV GALEX magnitudes. This sample was then compared with corresponding properties of isolated galaxies from the Local Orphan Galaxies catalogue (LOG) and paired galaxies. We found that different selection algorithms define different populations of isolated galaxies. The population of the LOG catalogue, selected from non-clustered galaxies in the Local Supercluster volume, mostly consists of low-mass spiral and late type galaxies. The SSFR upper limit in isolated and paired galaxies does not exceed the value of ~dex(-9.4). This is probably common for galaxies of differing activity and environment (at least at z 11.5 have higher (S)SFR than isolated galaxies. Our results suggest that the environment helps to trigger the star formation in the highest mass galaxies. We found that the fraction of AGN in the paired sample is only a little higher than in our isolated galaxy sample. We assume that AGN phenomenon is probably defined by secular galaxy evolution.

Relocation of Earthquakes in the New Madrid Seismic Zone: Estimation of 1D Velocity Structure and Geometry of a Seismogenic Fault

Abstract Determination of reliable hypocenters of earthquakes is crucial to earthquake seismology and to evaluate hazards associated with earthquakes. There are many associated computer codes for this purpose; however, most of the location algorithms are designed to determine hypocentral parameters based on previously determined velocity models. In contrast, we employed a location method that is independent of the initial velocity model, using a genetic algorithm (GA) to determine an optimal 1D velocity model and the locations of earthquakes. Using this GA, we relocated earthquakes that occurred in the New Madrid Seismic Zone (NMSZ) in the central United States between October 1989 and August 1992. The goal of this work was to delineate the possible fault planes by reliable relocation of those earthquakes and to determine a 1D velocity structure for the NMSZ. A total of 502 earthquakes recorded by 37 Portable Array for Numerical Data Acquisition (PANDA) stations were used in the relocation study. In the relocation process, the root mean square travel‐time residuals were reduced by ∼35%, corresponding to an average of 2.3 km deeper in depth, 0.7 km shift in latitude, and 0.8 km shift in longitude compared with those in the initial catalog locations. The hypocenters of the earthquakes can be subdivided into four groups based on their spatial distributions. The group that corresponds to the Cottonwood Grove fault (CGF) in the southwestern NMSZ represents a very steep plane, whereas the other three groups fall into Reelfoot fault (RF). We inverted P ‐ and S ‐wave travel times from the new hypocentral parameters to determine 1D velocity models. The resulting eight‐layered velocity models consist of a 2 km thick surface layer followed by seven 2 km thick layers, with V P ranges from 5.36 to 6.74 km/s and V S ranges from 2.83 to 3.90 km/s for both CGF and RF regions. Online Material: Interactive visualizations of hypocentral distributions.

TeV cosmic-ray proton and helium spectra in the myriad model II

Recent observations show that the spectra of cosmic ray nuclei start to harden above ∼ 102 GeV, which contradicts the conventional steady-state cosmic ray model. We had suggested that this anomaly is due to the propagation effect of cosmic rays released from local young cosmic ray sources; the total flux of cosmic rays should be computed with the Myriad Model, where a contribution from sources in the local catalog is added to the background. However, although the hardening could be elegantly explained in this model, the model parameters obtained from the fit are skewed toward a region with fast diffusion and a low supernova rate in the Galaxy, in disagreement with other observations. We further explore this model in order to set up a concordant picture. Two possible improvements related to cosmic ray sources are considered. First, instead of the usual axisymmetric disk model, we examine a spiral model for the source distribution. Second, for nearby and young sources which are necessary to explain the hardening, we allow for an energy-dependent escape. We find that a major improvement comes from incorporating an energy-dependent escape time for local sources, and with both modifications not only are the cosmic ray proton and helium anomalies resolved, but also the parameters attain values in a reasonable range compatible with other analyses.

Erratum to: The Lemnos 8 January 2013 (M w=5.7) earthquake: fault slip, aftershock properties and static stress transfer modeling in the north Aegean Sea

We investigate mainshock slip distribution and aftershock activity of the 8 January 2013 M w = 5.7 Lemnos earthquake, north Aegean Sea. We analyse the seismic waveforms to better understand the spatio-temporal characteristics of earthquake rupture within the seismogenic layer of the crust. Peak slip values range from 50 to 64 cm and mean slip values range from 10 to 12 cm. The slip patches of the event extend over an area of dimensions 16 × 16 km2. We also relocate aftershock catalog locations to image seismic fault dimensions and test earthquake transfer models. The relocated events allowed us to identify the active faults in this area of the north Aegean Sea by locating two, NE–SW linear patterns of aftershocks. The aftershock distribution of the mainshock event clearly reveals a NE–SW striking fault about 40 km offshore Lemnos Island that extends from 2 km up to a depth of 14 km. After the mainshock most of the seismic activity migrated to the east and to the north of the hypocenter due to (a) rupture directivity towards the NE and (b) Coulomb stress transfer. A stress inversion analysis based on 14 focal mechanisms of aftershocks showed that the maximum horizontal stress is compressional at N84°E. The static stress transfer analysis for all post-1943 major events in the North Aegean shows no evidence for triggering of the 2013 event. We suggest that the 2013 event occurred due to tectonic loading of the North Aegean crust.

The Law Library in an Information Age: It is Time to Do Away with the Local Online Catalog and Focus on Research Guides and Digital Content

This paper explores the relevance of the local public library catalog as a finding aid when information is digital. The current library catalog cannot compete with other online solutions. For law libraries, this is especially true as legal content providers like Westlaw, LexisNexis, and Bloomberg offer integrated legal resources as well as 'smart' data and linked citations. Libraries should abandon local control of the catalog and use centralized locations. Central locations will allow for linking and the eventual inclusion of 'smart' data. In short, libraries must must move from an integrated library system to a distributed library system to service digital patrons. Libraries must also create new solutions for finding, evaluating, selecting, and hosting resources. Possible pursuits include focusing on robust research guides and hosting valuable digital content with rich metadata that can be manipulated by computer algorithms.

Establishing a bibliographic database for hand press books : CERL project

AbstractBooks and other printed materials dating to the Hand Press period (ca. 1830) in Europe represent a special field of research. Consortium of European Research Libraries – CERL was founded in 1992 with an objective to establish a machine-readable database for this material. The goals of the project are twofold: to offer one site access to information about the Hand Press books, including holdings data (providing thus the function of a union catalogue), and enable downloading of records into local catalogues, reducing processing costs. To organize a union database named Hand Press Book (HPB), detailed arrangements are necessary to harmonize different cataloguing practices and machine-redable formats, establish use of thesaurus files etc., and make the records as useful as possible. Minimal level requirements have been defined and the characteristics of contributed files are described. The user is also provided with information on characteristics of the material from respective library collections, as well as with detailed instructions for successful searching. Besides, CERL systematically collects information on other related projects and institutions, covering the Hand Press period, manuscripts, together with the history of the book, printing and publishing. Cooperation and project coordination of European libraries is one of the main benefits of this project in which the Slovenian National and University Library participates from the very beginning.

Quod licet bovi, convenit Iovi: multifunctionality of a bibliographic database

AbstractWithin the COBISS system, the bibliographic database is supposed to provide a whole range of objectives: full operation of the Slovenian union catalogue COBIB, including all local catalogues, modules like cataloguing, acqusition, loan and interlibrary loan, and outputs as the national bibliography and bibliographies of researchers’ for projects’ applications required by the Ministry for Education, Sports and Science. The comparison of the two functions, one of a catalogue, and second of a bibliography, shows a great amount of overlapping which can also be seen in the IFLA study Functional requirements for bibliographic records. Four basic user tasks are defined: find, identify, select and obtain, irrelevant of the particular function the database should provide. Once defining all the objectives, both data input and the development of necessary tools can be planned, together with a reasonable human resources management.

Biodiesel: Environmental Friendly Alternative to Petrodiesel

Biodiesel is a renewable, efficient, environmentally friendly and biodegradable fuel made from vegetable oil, including waste cooking oil. In the United States, soybean oil is the principal oil being utilized for biodiesel [1]. Animal fats, oils and greases generated in the food industry and restaurants can be recovered by interceptors and traps as a feedstock for biodiesel [2]. Insect fat has also been proposed as a promising resource for biodiesel production [3]. Biodiesel can be blended with conventional petrodiesel in any proportion (even 1% biodiesel will increase engine lubrication by 65%) for use in vehicles with an unmodified diesel engine. Unburned hydrocarbons, carbon monoxide and particulate matter are substantially reduced in the exhaust fumes, up to 75% cleaner than petrodiesel made from fossil fuels. Sulphur dioxide emissions are eliminated as biodiesel contains no sulphur. It has significant potential to reduce greenhouse gas emissions particularly in the trucking industry [4]. In Canada canola oil is produced in massive quantities for domestic marketing. A large amount goes through restaurant deep fryers and must be disposed of after a few days of use [5]. The federal government provides, through the Sustainable Development Technology Canada’s NextGen Biofuels Fund, ongoing support in the development of advanced renewable biofuels [6]. Annually, the Canadian Renewable Fuels Association presents the Green Fuels Award to honour pioneers in the development, commercialization and promotion of low carbon renewable fuels. In Ontario, biodiesel is exempted from the provincial tax of 14.3 cents per liter. The largest biodiesel plant, Great Lakes Biodiesel Inc. located in Well and, produces 45 million gallons of ASTM 6751 quality biodiesel made from vegetable oils [7]. It has received BQ-9000 Producer status from the National Biodiesel Accreditation Commission for efficient production of high quality fuel to meet the growing renewable energy demands. Today finding an outlet is getting easier a new website has started up to catalog locations where drivers can get biodiesel for their cars and trucks [8]. Biodiesel is primarily obtained from the base catalyzed transesterification reaction of oils or fats. An American company, HomeBiodieselKits.com, sells biodiesel processing equipment (for three thousand dollars) that can make the processing of used cooking oil into biodiesel much easier [9]. Some people choose biofuel processors to convert local crops (corn) into renewable fuel (fiber cellulosic ethanol) that can replace gasoline or create electricity, thereby saving money and helping the environment. Biodiesel must meet a cetane number specification of 40 or more (to be higher than petrodiesel) [10], which is a measurement of the fuel combustion quality during compression ignition [11]. Other measurements of diesel quality include cold-flow properties, density, lubricity and sulfur content.

Lack of Spatiotemporal Localization of Foreshocks before the 1999 Mw 7.1 Duzce, Turkey, Earthquake

We use a matched‐filter technique to detect small seismic events before the M w 7.1 Duzce earthquake that are not included in the regular catalog. The study employs extensive waveform dataset recorded by a 10‐station fault zone array near the epicenter of the Duzce earthquake, deployed about three months before the event. We use 3134 earthquakes within 20 km of the Duzce epicenter listed in the local catalog as templates to scan through waveforms recorded within ∼65 hours before the Duzce earthquake. The analysis reveals 262 newly detected events in this time interval, which is ∼5 times more than the 55 events listed in the original catalog. Most of the events occur to the west of the Duzce epicenter, which was initiated between a more active western and relatively quite eastern fault segments. The results do not indicate a localizing foreshock process that accelerates in time and/or involves progressive concentration of activity around the mainshock hypocenter during the preceding 65 hour period. Instead, we find that the Duzce source region becomes less active during the ∼20 hours immediately before the mainshock. Our results, together with other recent studies, suggest that progressive acceleration and localization of foreshocks around the mainshock epicenter is not a general phenomenon. Online Material: Figures of timing of recorded waveforms, peak ground velocities, foreshock activity, seismicity rate, and temporal evolution of earthquake activity, vertical waveforms, and distribution of template events.

The Effectiveness of Copy Cataloging at Eliminating Typographical Errors in Shared Bibliographic Records

Typographical errors in bibliographic records can cause retrieval problems in online catalogs. This study examined one hundred typographical errors in records in the OCLC WorldCat database. The local catalogs of five libraries holding the items described by the bibliographic records with typographical errors were searched to determine whether each library had corrected the errors. The study found that only 35.8 percent of the errors had been corrected. Knowledge of copy cataloging error rates can help underscore the importance of quality data in bibliographic utilities and, further, can serve as an indication to libraries whether they need to pay more attention to correcting typos in the copy cataloging process.

Coping with the storm

Purpose – The purpose of this paper is to present a process, as a proof-of-concept, that automates the tracking of updates to name authority records (NARs), the downloading of revised NARs into local catalog system, and subsequent bibliographic file maintenance (BFM), in response to the programmatic manipulation of the Library of Congress Name Authority File (LCNAF). Design/methodology/approach – A proof-of-concept process to automate NAR updates and BFM in local catalog, using OCLC LCNAF SRU Service, MARCEdit, XSLT, and AutoIt, is built and subsequently tested using data from both test and production catalog servers at Michigan State University Libraries. Findings – The proof-of-concept process tested is proved to be successful in general though scalability and diacritics issues have to be addressed before it can become fully operational in a production environment. Originality/value – This process enables libraries, especially those without third-party authority control service, to handle the phased reissuance of LCNAF and related BFM in an automatic fashion with minimal human intervention.

Shared Resources, Shared Records

Many libraries share regional, statewide, or even national union or consortium catalogs to enable consolidated search and display of participant holdings. These catalogs typically duplicate search capabilities provided by individual libraries’ local catalogs. Search TRLN is a discovery layer built to support both group and individual library catalog interfaces for the four member institutions of the Triangle Research Libraries Network. In 2010, the Shared Records Pilot Task Group extended this shared catalog concept to the individual bibliographic record level. In this model, individual member libraries assume responsibility for building and maintaining record sets for commonly held electronic collections on behalf of the consortium. Today the program includes more than 220,000 shared records representing 765,000 individual library holdings. This has resulted in considerable savings in staff costs, processing costs, and metadata storage and suggests an evolving model for catalogers as managers, rather than as creators and curators, of metadata. This article discusses the evolution of this project, the development of staff trust necessary to let go of proprietary metadata, and the systems logic needed for implementation. The article closes with criteria for assessing the success of the program, including improvements in catalog display, throughput and timeliness, time savings, and elimination of duplicated maintenance activities.

Alignment of Citation Behaviors of Philosophy Graduate Students and Faculty

Objective – This study analyzes sources cited by graduate students in philosophy at the University of Colorado Boulder (UCB) in 55 PhD dissertations and master’s theses submitted between 2005 and 2010, to discover their language, age, format, discipline, whether or not they were held by the library, and how they were acquired. Results were compared to data previously collected about sources cited by philosophy faculty at UCB, in books published between 2004 and 2009, to identify how closely citation behaviors aligned between the two groups.
 
 Methods – Citations were counted in the PhD dissertations and master’s theses. Citations to monographs were searched against the local catalog to determine ownership and call number. Comparison numbers for faculty research were collected from a previous study. Results were grouped according to academic rank and analyzed by format, language, age, call number, ownership, and method of purchase.
 
 Results – Graduate students cited mostly books, though fewer than commonly found in other studies. Citations were almost entirely of English language sources. Master’s students cited slightly newer materials than doctoral students, who in turn cited newer materials than faculty. The library owned most cited books, and most of those were purchased on an approval plan. Doctoral students most frequently cited resources outside the discipline of philosophy, in contrast to master’s students and faculty.
 
 Conclusions – The citation behavior of graduate students in philosophy largely, but not entirely, mirrors that of the faculty. Further study of citation behavior in humanities disciplines would be useful. Understanding the behavior of philosophers can help philosophy librarians make informed choices about how to spend library funds.

Where do we go with Union Catalogues?

The United Kingdom boasts union catalogues for its major research libraries, journal holdings, archives and, most recently, for its public library collections. For researchers wanting to locate material across the UK, such aggregations have long served as a first stop for researchers wanting to find the right material and also provided a showcase for our formidable research collections. In the global networked environment, search engines and social networks can fulfil much of the functionality of union catalogues and have become the natural places to which our users go for search and discovery, even in academic situations. Right now, there is a ‘disconnect’ between the data describing our collections and the places users first turn to start their searches. This can be fixed by exposing descriptive data to wider audiences beyond the silo of the local catalogue, but data publishing is a fast moving area with little obvious short-term institutional-level gain and some start-up barriers. Publishing library data to the open web at the level of a national aggregation would utilize existing skill sets and infrastructure, minimize risk and maximize impact.

Information Retrieval Using a Middleware Approach

This paper explores the use of a mediator/wrapper approach to enable the search of an existing library management system using different information retrieval protocols. It proposes an architecture for a software component that will act as an intermediary between the library system and search services. It provides an overview of different approaches to add Z39.50 and Search/Retrieval via URL (SRU) functionality using a middleware approach that is implemented on the BISIS library management system. That wrapper performs transformation of Contextual Query Language (CQL) into Lucene query language. The primary aim of this software component is to enable search and retrieval of bibliographic records using the SRU and Z39.50 protocols, but the proposed architecture of the software components is also suitable for inclusion of the existing library management system into a library portal. The software component provides a single interface to server-side protocols for search and retrieval of records. Additional protocols could be used. This paper provides practical demonstration of interest to developers of library management systems and those who are trying to use open-source solutions to make their local catalog accessible to other systems.

Iranian earthquakes, a uniform catalog with moment magnitudes

A uniform earthquake catalog is an essential tool in any seismic hazard analysis. In this study, an earthquake catalog of Iran and adjacent areas was compiled, using international and national databanks. The following priorities were applied in selecting magnitude and earthquake location: (a) local catalogs were given higher priority for establishing the location of an earthquake and (b) global catalogs were preferred for determining earthquake magnitudes. Earthquakes that have occurred within the bounds between 23–42° N and 42–65° E, with a magnitude range of M W 3.5–7.9, from the third millennium BC until April 2010 were included. In an effort to avoid the “boundary effect,” since the newly compiled catalog will be mainly used for seismic hazard assessment, the study area includes the areas adjacent to Iran. The standardization of the catalog in terms of magnitude was achieved by the conversion of all types of magnitude into moment magnitude, M W, by using the orthogonal regression technique. In the newly compiled catalog, all aftershocks were detected, based on the procedure described by Gardner and Knopoff (Bull Seismol Soc Am 64:1363–1367, 1974). The seismicity parameters were calculated for the six main tectonic seismic zones of Iran, i.e., the Zagros Mountain Range, the Alborz Mountain Range, Central Iran, Kope Dagh, Azerbaijan, and Makran.

A Unified Seismic Catalog for the Iranian Plateau (1900-2011)

Online Material: De‐clustered and non‐declustered earthquake catalogs. The first seismograph in Iran was installed in 1959, and this marked the beginning of the national seismic catalog. The seismic network grew with years, but its coverage, the instrumental features, and the details of magnitude calculation changed over time, resulting in a highly heterogeneous national seismic catalog. In this work, we present a unified and homogeneous catalog for the Iranian plateau ( M w≥4), created by merging data from two local catalogs and seven international agencies, each one covering the magnitude scale and period illustrated in Figure 1. This operation requires the conversion of different magnitudes used by the single agencies to a common type. The moment magnitude ( M w) is chosen as reference for its physical meaning (Kanamori, 1977) and because it does not saturate. In this attempt to convert different magnitude scales to M w, regression relations that take into account errors on both variables are used, and a specific statistical analysis shows that the region under study (24°N–42°N, 43°W–66°E) is better described when subdivided into two tectonic domains, Zagros and Alborz–Central Iran, characterized by different regression relations. A precedence scheme is then established to select the magnitude value to be preferred when the same event is reported by several catalogs with different magnitude scales and/or values. The resulting unified catalog for the Iranian plateau, spanning 1900–2011, is finally presented also in a declustered form for time‐independent seismic hazard estimates. Figure 1. Magnitude scales provided by the original databases used to compile the unified earthquake catalog of Iran between 1900 and 2011. According to Global Positioning System measurements, Iran is presently affected by the northward drift of the Arabian plate in respect to the Eurasian plate at the rate of 23 mm/yr (Vernant et al. , 2004; Masson et al. , 2007 …