Regional Catalogues Research Articles

О возможной связи землетрясений со сменой знака радиальной компоненты межпланетного магнитного поля

This work is devoted to an experimental study of the possible relationship between earthquakes and interplanetary magnetic field (IMF) variations. For the analysis, we use world and regional catalogs of earthquakes and a catalog containing data on the IMF sector structure for several decades. The main methodological technique consists in a comparative analysis of the occurrence rate of earthquakes on the days when Earth crosses the boundary between IMF sectors with the days when Earth is inside the sector. The sign of the IMF radial component is utilized as an indicator of the events on which the oscillation mode of Earth's magnetosphere depends. The sign reversal signals the probable crossing of the boundary between the IMF sectors by Earth, or, in other words, the crossing of the heliospheric current sheet by Earth. The hypothesis about the relationship between IMF variations and seismic activity is that IMF fluctuations, penetrating into the magnetosphere, excite ULF electromagnetic oscillations in the magnetosphere, which, in principle, can affect the physical processes in upcoming earthquake sources. We have found a weak, but statistically significant relationship between IMF variations and seismic activity. We also consider other IMF parameters that control ultra-low-frequency oscillations of the geomagnetic field.

On possible relation of earthquakes with the sign change of the interplanetary magnetic field radial component

This work is devoted to an experimental study of the possible relationship between earthquakes and interplanetary magnetic field (IMF) variations. For the analysis, we use world and regional catalogs of earthquakes and a catalog containing data on the IMF sector structure for several decades. The main methodological technique consists in a comparative analysis of the occurrence rate of earthquakes on the days when Earth crosses the boundary between IMF sectors with the days when Earth is inside the sector. The sign of the IMF radial component is utilized as an indicator of the events on which the oscillation mode of Earth's magnetosphere depends. The sign reversal signals the probable crossing of the boundary between the IMF sectors by Earth, or, in other words, the crossing of the heliospheric current sheet by Earth. The hypothesis about the relationship between IMF variations and seismic activity is that IMF fluctuations, penetrating into the magnetosphere, excite ULF electromagnetic oscillations in the magnetosphere, which, in principle, can affect the physical processes in upcoming earthquake sources. We have found a weak, but statistically significant relationship between IMF variations and seismic activity. We also consider other IMF parameters that control ultra-low-frequency oscillations of the geomagnetic field.

Long-term analysis of rainfall-induced landslides in Umbria, central Italy

Analyses of historical records of landslides and climate variables are useful tools to search for correlations between damaging landslide events and their triggers. In this work, we investigate the temporal and geographical relationships between two long-term historical series of catalogued landslide occurrences and daily rainfall data in Umbria, a central Italian region, from 1928 to 2001. Moreover, we search for changes in the frequency and density of landslides, and in the characteristics of the associated rainfall events. Using a consolidated approach, partially modified, we find that the rainfall events that have produced rainfall-induced landslides in Umbria changed in space and time during observation period and between two considered sub-periods (1928–1975 and 1976–2001). In particular, we find that: (i) the monthly distribution of landslides associated with rainfall events is quite different than that of all landslides in the regional catalogue; (ii) the spatial and temporal distribution of REL changed from the older (most events occurred in winter) to the recent period (most events occurred in autumn); (iii) the recent most rainfall events associated with landslides are characterized by a lower cumulated rainfall and a shorter duration, sign of an increased propensity of the regional territory to produce landslides over time.

Прецедентно-экстраполяционная оценка сейсмической опасности в районе Сахалина и Южных Курил

The paper describes the algorithm and the results of the seismic hazard estimate in the Sakhalin and Southern Kurils region based on the data of the Japan Regional Catalogue (JMA). A nonlinear differential equation of the second order is used as a mathematical model, and algorithms for optimization and predictability estimation are presented by the author's solutions. The forecasting algorithm is based on the search for seismic activity zones in which the current activity trends correspond to foreshock sequences recorded before strong earthquakes (precedents) that have already occurred. The earthquake time is calculated with extrapolating the detected trends to the level of activity that occurred at the time of the precedent earthquake. By the example of precedent foreshock sequences in Japan, it is shown that the lead time of such a forecast reaches 10–15 years and its implementation is due to the preservation and stability of the identified trends. A map of potentially dangerous zones for Sakhalin and the Kuril Islands and some examples of calculating the time of strong earthquakes according to the JMA catalogue as of August 31, 2018 are presented. Action sequence in identifying the potentially dangerous trends in seismic activity and the specifics of possible use of the technique in the Sakhalin region are considered.

Synthetic seismicity distribution in Guerrero–Oaxaca subduction zone, Mexico, and its implications on the role of asperities in Gutenberg–Richter law

Abstract. Seismicity and magnitude distributions are fundamental for seismic hazard analysis. The Mexican subduction margin along the Pacific Coast is one of the most active seismic zones in the world, which makes it an optimal region for observation and experimentation analyses. Some remarkable seismicity features have been observed on a subvolume of this subduction region, suggesting that the observed simplicity of earthquake sources arises from the rupturing of single asperities. This subregion has been named SUB3 in a recent seismotectonic regionalization of Mexico. In this work, we numerically test this hypothesis using the TREMOL (sThochastic Rupture Earthquake MOdeL) v0.1.0 code. As test cases, we choose four of the most significant recent events (6.5 < Mw < 7.8) that occurred in the Guerrero–Oaxaca region (SUB3) during the period 1988–2018, and whose associated seismic histories are well recorded in the regional catalogs. Synthetic seismicity results show a reasonable fit to the real data, which improves when the available data from the real events increase. These results give support to the hypothesis that single-asperity ruptures are a distinctive feature that controls seismicity in SUB3. Moreover, a fault aspect ratio sensitivity analysis is carried out to study how the synthetic seismicity varies. Our results indicate that asperity shape is an important modeling parameter controlling the frequency–magnitude distribution of synthetic data. Therefore, TREMOL provides appropriate means to model complex seismicity curves, such as those observed in the SUB3 region, and highlights its usefulness as a tool to shed additional light on the earthquake process.

KAMCHATKA AND COMMANDER ISLANDS

The seismicity review of Kamchatka and surrounding territories for 2014 is given. In Kamchatka earthquake catalogue minimum local magnitude of completeness is MLmin=3.5, and for earthquakes under the Okhotsk sea with h≥350 kmMLmin=3.6. The Kamchatka earthquake catalogue for 2014 with ML3.5, published in the Appendix to this annual, includes 1114 events. 86 earthquakes of the catalogue with ML=3.35–6.2 were felt in Kamchatka and surrounding areas with seismic intensity I ranged from 2 to 5 according the MSK-64 scale. For all events with ML5.0 occurred in the area of responsibility of the KB GS RAS in 2014, an attempt to calculate the seismic moment tensor (SMT) was made. There are 40 such events in the regional catalogue. For 36 earthquakes, the SMT and depth h of the equivalent point source were calculated successfully. The calcu-lations were performed for the SMT double-couple model using a nonlinear algorithm. In 2014, a typical location of the earthquake epicenters was observed in the Kamchatka zone. In 2014, the seismicity level in all selected zones and in the region as a whole corresponded to the background one according to the “SESL’09” scale. The number of recorded events with ML3.6 and strong earthquakes with ML5.1 is close to the average annual value. Anomalous and outstanding events were not recorded.

A Catalog of Bipolar Active Regions Violating the Hale Polarity Law, 1989 – 2018

There is no list of bipolar active regions (ARs) with reverse polarity (anti-Hale regions), although statistical investigations of such ARs (bearing the imprint of deep subphotospheric processes) are important for understanding solar-cycle mechanisms. We studied 8606 ARs from 1 January 1989 to 31 December 2018 to detect anti-Hale regions and to compile a catalog. The Solar and Heliospheric Observatory (SOHO) and the Solar Dynamics Observatory (SDO) data, as well as the Debrecen Photoheliographic Data, the Mount Wilson Observatory catalog and drawings, and the USAF/NOAA Solar Region Summary were used. Complex, ambiguous cases related to anti-Hale region identification were analyzed. Two basic and four additional criteria to identify an AR as an anti-Hale region were formulated. The basic criteria assume that: i) dominating features of an AR have to form a bipole of reverse polarity with sunspots/pores of both polarities being present; ii) magnetic connections between the opposite polarities has to be observed. A catalog of anti-Hale regions (275 ARs) is compiled. The catalog contains: NOAA number, date of the greatest total area of sunspots, coordinates, and corrected sunspot area for this date. The tilt and the most complex achieved Mount Wilson magnetic class are also provided. The percentage of anti-Hale groups meeting the proposed criteria is ~3.0% from all studied ARs, which is close to early estimations by authors who had examined each AR individually: ~2.4% by Hale and Nicholson (Ap.J. 62, 270, 1925) and ~3.1% by Richardson (Ap.J. 107, 78, 1948). The enchancement of the anti-Hale percentage in later research might be related to: i) increasing sensitivity of instruments (considering smaller and smaller bipoles); ii) the ambiguities in the anti-Hale region identification.

An Analysis of the Generalized Vicinity of a Large Earthquake Using Regional Data: The Kuril–Kamchatka Region

The method for constructing the generalized vicinity of a large earthquake as put forward and implemented in (Rodkin, 2008, 2012, 2020; Rodkin and Tikhonov, 2016) was previously used for analysis of world earthquake catalogs only. The use of this method for the analysis of regional catalogs presupposes a lower magnitude threshold for classification of large events and incorporation of regional seismicity peculiarities. We constructed the generalized vicinity from regional data for the Kuril Islands and Kamchatka. The same seismicity features have been identified as those for the generalized vicinity based on worldwide data; in particular, we identified the effect of earthquake hypocenters getting shallower in the near vicinity of a large earthquake. However, the regional data revealed the unexpected effect of a temporary clustering of large earthquakes, including those cases where they were far from each other. The volumes of higher activity involve considerable parts of the subduction zone far from each other both along the trench and over depth. We have estimated characteristic parameters of these clusters and the fraction of statistically dependent and independent large events. The mutual influence of seismicity at different depths has been discussed.

Towards a regional, automated full moment tensor inversion for medium to large magnitude events in the Iranian plateau

Considering the high seismicity rate of the Iranian plateau, the development and implementation of an automated routine for near-real-time determination of earthquake point source parameters would be extremely beneficial, e.g., for dedicated seismological studies, constraining the regional stress field, and shakemap assessment. We discuss the implementation of a fast, automated regional moment tensor inversion routine, based on SeisComP3 and KIWI tool packages. To assess the routine efficiency, we used a dataset including 90 earthquakes spatially distributed within all seismotectonic provinces of Iran, recorded at local to regional distances, with magnitudes in the range MN 4.5–7.3. Resolved moment tensor solutions and source parameters are in most cases in good agreement with reference ones from global and regional catalogs. However, we identify consistent differences in magnitudes and depths, with respect to global catalogs, which can be attributed to a higher resolution of our approach, using local and regional data and considering regional velocity models. The depth estimations are shallower than in reference global catalogs but compatible with the tectonic settings of the Iranian region. The analysis of the selected dataset is accompanied by a test run of automated processing for 8 months of online operation, from July 2019 to February 2020. The processing time in online routine, with an average of ~ 23 min, mostly depends on the magnitude, number of stations, azimuthal coverage, data quality, and complexity of the crustal model, so that computation times may vary significantly for earthquakes located in different Iranian provinces.

Movement of individual humpback whales between wintering grounds of Oceania (South Pacific), 1999 to 2004

The movement of individual humpback whales between regional breeding grounds of Oceania (South Pacific) was documented by individualidentification photographs collected from 1999 to 2004. Photographs were collected with comparable effort across the six years in four primaryisland breeding grounds: New Caledonia, Tonga (Vava’u) the Cook Islands and French Polynesia (Mo’orea and Rurutu); with smaller effort inadjacent regions: Vanuatu, Fiji, Samoa, Niue and American Samoa. Interchange among wintering grounds was assessed first with all usablephotographs included in each regional catalogue, representing 1,080 regional sightings (including within-region and between-region resightings)of 949 individual whales from Oceania. From this, 28 cases of movement between (mostly adjacent) regions were documented. Previouslyundocumented interchange was found between regions of central Oceania and the western South Pacific. No individual was sighted in more thantwo regions during this six-year period. The documented movement between regions was one-directional, except for one individual sighted first inFrench Polynesia, then in American Samoa and then back in French Polynesia (each in different years). Only one whale was resighted in more thanone region during the same winter season. No directional trend was apparent and movement between regions did not seem to be sex specific. Asystematic quality control review of all catalogues was then implemented to calculate standardised indices of within-region return and betweenregion interchange, resulting in a quality controlled catalogue of 776 regional sightings of 659 individuals. The standardised indices confirmed thatthe probability of between-region interchange was low, relative to within-region return, supporting the assumption of multiple management unitsor stocks in Oceania. The relative isolation of breeding regions and the movement of individuals across the longitudinal borders of Antarcticmanagement Areas V and VI has important implications for the allocation of historical catches from the Antarctic and therefore, for assessingcurrent levels of recovery for breeding stocks

Linking Atmospheric Rivers to Annual and Extreme River Runoff in British Columbia and Southeastern Alaska

AbstractThis study quantifies the contribution of atmospheric rivers (ARs) to annual and extreme river runoff and evaluates the relationships between watershed characteristics and AR-related maximum river runoff across British Columbia and southeastern Alaska (BCSAK). Datasets used include gauged runoff from 168 unregulated watersheds, topographic characteristics of those watersheds, a regional AR catalog, and integrated vapor transport fields for water years (WYs) 1979–2016. ARs contribute ~22% of annual river runoff along the Coast and Insular Mountains watersheds, which decreases inland to ~11% in the watersheds of the Interior Mountains and Plateau. Average association between ARs and annual maximum river runoff attains >80%, >50%, and <50% along the watersheds of the western flanks of the Coast Mountains, the Interior Mountains, and Interior Plateau, respectively. There is no significant change in AR-related extreme annual maximum runoff across BCSAK during 1979–2016. AR conditions occur during 25 out of 32 of the flood-related natural disasters in British Columbia during WYs 1979–2016. AR-related annual maximum runoff magnitude is significantly higher than non-AR-related annual maximum runoff for 30% of the watersheds studied. Smaller and steeper watersheds closer to the coast are more susceptible to AR-related annual maximum runoff than their inland counterparts. These results illustrate the importance of AR activity as a major control for the distribution of peak runoff in BCSAK. This work provides insights on the hydrological response of watersheds of northwestern North America to landfalling ARs that may improve flood risk assessment and disaster management in this region.

First assessment of interchange of humpback whales between Oceania and the East coast of Australia

The interchange of individual humpback whales between the wintering grounds of Oceania (South Pacific) and the east coast of Australia weredocumented by individual identification photographs collected from 1999 to 2004. Interchange was assessed using regional catalogues of flukephotographs, totalling 672 individuals from Oceania (represented by New Zealand, New Caledonia, Vanuatu, Fiji, Samoa, Tonga, Niue, Cook Island,French Polynesia and American Samoa) and 1,242 individuals from Hervey Bay and Byron Bay representing the southbound and the northboundmigration along the east coast of Australia (EA). Overall, there were seven documented movements between EA and Oceania. Four instances ofmovement of four individuals were documented between EA and the closest breeding grounds of New Caledonia. A further three movements wererecorded between EA and a small catalogue (n = 13) from the New Zealand migratory corridor. In contrast, during this same period, 20 cases ofinterchange were documented among nine breeding grounds: French Polynesia, Cook Islands, Niue, American Samoa, Samoa, Tonga, Fiji, Vanuatuand New Caledonia. The low level of interchange between Oceania and the east coast of Australia has important implications for understanding thestock structure and abundance of humpback whales in the South Pacific.

Rainfall and rockfalls in the Canary Islands: assessing a seasonal link

Abstract. Rockfalls are frequent and harmful phenomena occurring in mountain ranges, coastal cliffs, and slope cuts. Although several natural processes occur in their formation and triggering, rainfall is one of the most common causes. The prediction of rock failures is of social significance for civil protection purposes and can rely on the statistical analysis of past rainfall conditions that caused the failures. The paper describes the analysis of information on rainfall-induced rockfalls in Gran Canaria and Tenerife, Canary Islands (Spain). An analysis of the monthly rainfall versus the monthly distribution of rockfalls reveals that they are correlated for most of the year, except in summer, when other triggers act to induce collapses. National and regional catalogs with hourly and daily rainfall measurements are used to reconstruct the cumulated amount (E) and the duration (D) of the rainfall responsible for the rock failures. Adopting a consolidated statistical approach, new ED rainfall thresholds for possible rockfall occurrence and the associated uncertainties are calculated for the two test sites. As far as is known, this is the first attempt to predict this type of failure using the threshold approach. Using the rainfall information, a map of the mean annual rainfall is obtained for Gran Canaria and Tenerife, and it is used to assess the differences between the thresholds. The results of this study are expected to improve the ability to forecast rockfalls in the Canary Islands in view of implementing an early-warning system to mitigate the rockfall hazard and reduce the associated risk.

Cincuenta libros escolares de la Península de Yucatán, siglo XIX

El propósito inicial de esta investigación fue elaborar un catálogo de libros escolares impresos en la Península de Yucatán durante el siglo XIX. En el proceso del registro detallado de libros para la confección del catálogo aparecieron vínculos frecuentes entre la élite letrada local y la dinámica actividad de impresión y reimpresión de libros escolares en la región. El catálogo regional de libros escolares decimonónicos va incluido al final del artículo, en forma de anexo: es un listado provisional que necesariamente seguirácreciendo con el aporte de los investigadores del sureste mexicano. Por ahora se trata de una nómina de medio centenar de libros escolares impresos en Campeche, Mérida y sus alrededores durante aquel siglo. La variedad de ramos educacionales ─patente en los libros escolares registrados─ es suma de los campos de conocimiento que la política pública de México designó como prioritarios para la educación en el inicio de la etapa independiente de la nación y posterior a las Leyes de Reforma (separación de Iglesia y Estado). Labúsqueda y registro de libros escolares, impresos regionalmente, permitió documentar y escribir una narrativa sobre la relación entre élites letradas locales y relevancia de la educación pública decimonónica en ciudades como Campeche y Mérida.

Bar effect on gas-phase abundance gradients. I. Data sample and chemical abundances

ABSTRACT Studies of gas-phase radial metallicity profiles in spirals published in the last decade have diminished the importance of galactic bars as agents that mix and flatten the profiles, contradicting results obtained in the 1990s. We have collected a large sample of 2831 published H ii region emission-line fluxes in 51 nearby galaxies, including objects both with and without the presence of a bar, with the aim of revisiting the issue of whether bars affect the radial metal distribution in spirals. In this first paper of a series of two, we present the galaxy and the H ii region samples. The methodology is homogeneous for the whole data sample and includes the derivation of H ii region chemical abundances, structural parameters of bars and discs, galactocentric distances, and radial abundance profiles. We have obtained O/H and N/O abundance ratios from the Te-based (direct) method for a subsample of 610 regions, and from a variety of strong-line methods for the whole H ii region sample. The strong-line methods have been evaluated in relation to the Te-based one from both a comparison of the derived O/H and N/O abundances for individual H ii regions and a comparison of the abundance gradients derived from both methodologies. The median value and the standard deviation of the gradient distributions depend on the abundance method, and those based on the O3N2 indicator tend to flatten the steepest profiles, reducing the range of observed gradients. A detailed analysis and discussion of the derived O/H and N/O radial abundance gradients and y-intercepts for barred and unbarred galaxies is presented in the companion Paper II. The whole H ii region catalogue including emission-line fluxes, positions, and derived abundances is made publicly available on the CDS VizieR facility, together with the radial abundance gradients for all galaxies.

Seismic source modeling and probabilistic seismic hazard analysis for Bangladesh

The probabilistic seismic hazard analysis (PSHA) has been performed for Bangladesh using background seismicity, crustal fault, and subduction zone source models. The latest ground motion prediction equations (GMPEs) that are developed using global data sets have been used to estimate ground motion. The uncertainties in seismic sources and GMPEs to estimate ground motion are accounted using the logic tree approach. The activity rates of the background and regional seismicity sources are estimated using a declustered and complete catalog of the study regions. The activity rates of the crustal fault and subduction zone sources are estimated from the geodetic strain rates using the well-accepted relationships. The peak ground acceleration (PGA) and spectral acceleration (SA) at spectral periods of 0.2, 0.5, 1.0, 2.0, 5.0, and 10.0 s have been estimated at a grid size of 0.250 at the bedrock ground condition. The PGA and SA maps of various spectral periods have been prepared for Bangladesh for both 10% and 2% probability of exceedance in 50 years. These seismic hazard maps can be used for seismic risk management of Bangladesh.

Catalog of the Biting Midges of the World (Diptera: Ceratopogonidae).

A list of all valid 6,206 extant and 296 fossil species of Ceratopogonidae described worldwide is provided, along with all their synonyms. A full citation and the country of origin of the type is given, with some larger countries also providing a more specific state or province. For the first time, worldwide, nomina dubia are identified. Numbers of species of each genus and subgenus are listed. Within subfamilies and tribes, genera are listed alphabetically. Five species have newly recognized authors, four have new names and 28 new combinations are recognized, with these listed in a table. A commentary on the state of the systematics in the family and particularly of Culicoides Latreille is given. The museums of the world are listed with the types of various authors of Ceratopogonidae species indicated. Authors providing regional catalogs, as well as summation of various collections are tabulated. The rate of description since 1758 indicates a steady progression of description, with, for example, 1,231 valid species described since the compilation of the world species by Borkent Wirth (1997), till the end of 2018. The diversity in each Region is compared and the numbers of species shared between adjacent Regions presented.

The 1258 Earthquake in Onteniente (Southeast Spain) Not Reported until 2002 in Any Catalog

AbstractHistorical seismicity is particularly important for the southeast region of the Iberian Peninsula, where large earthquakes are separated by long periods of time. The study of medieval earthquakes presents special difficulties. In this study, we review the earthquake of 1258 in the town of Onteniente, an event that was not present in regional catalogs of the Iberian Peninsula until 2002. Information about the earthquake is based on a contemporary letter by King James I of Aragon, who granted tax exemptions to the people of the town of Onteniente because of the damage.

Technologies and software for the regional catalog of Russian spacecraft satellite data

The results of research and development devoted to the creation of technologies and software for the satellite data catalog from Russian spacecraft, formed at the Regional Center for Remote Sensing of the Earth in Krasnoyarsk, are examined. The created software package provides a full cycle of operations with satellite data, including their downloading from the Roscosmos Geoportal, pre-processing, archiving, conversion and visualization operations using a specialized geographic information web system. Practical experience with the data provider revealed a number of problems in the source information, which were taken into account when creating the software. In particular, some files were damaged (files are filled with zeros or have an incomplete size), some files in the data folder were missing, the names of files and directories did not meet the declared standards, and so on. Separately, we should pay attention to significant delays in data delivery, which reached six months or more. These problems were taken into account when creating the software.

GPU-Accelerated Automatic Microseismic Monitoring Algorithm (GAMMA) and Its Application to the 2019 Ridgecrest Earthquake Sequence

Abstract Foreshocks and/or aftershocks play critical roles in improving our understanding of the processes of faulting, such as nucleation of earthquakes, earthquake triggering, and postseismic deformation. A rapid and accurate earthquake detection and location algorithm can provide timely information of seismic activities, thereby benefitting our understanding of physical mechanisms of faulting and seismic hazard assessment. We have developed a graphic processing unit (GPU)-accelerated automatic microseismic monitoring algorithm (GAMMA) for accurate and near real-time detection and location of earthquakes. GAMMA utilizes methods based on backprojection to automatically detect potential earthquakes, and then the waveforms of qualified earthquakes are selected as templates when searching for small earthquakes in continuous recordings using the template-matching algorithm. The use of GPUs has substantially accelerated the calculations and has made GAMMA capable of (near-)real-time earthquake monitoring. We have successfully applied GAMMA to the 2019 Ridgecrest earthquake sequence in southern California. The number of earthquakes detected by GAMMA is more than 21 times that documented in the regional catalog. The more complete catalog determined by GAMMA may provide crucial information for improving our understanding of the physical mechanisms of faulting and also supply useful constraints for a variety of types of studies, including dynamic rupture simulations and crustal deformation modeling.