Tsunami on July 29 (30), 2025 in the Kamchatka-Kuril Zone: Instrumental Observation and Modeling

The timely detection of lightning location and observations of the spatial and temporal development of thunderstorm clouds in many cases enable avoiding or reducing considerably the damage caused by them. In recent years, the instrumental methods of thunderstorm detection have been developed in Roshydromet. Two sets (of four sensors each) of LS8000 lightning detectors were installed in the North Caucasian and Moscow regions. Considered is one of the possible ways of deriving the equation for computing the number of thunderstorm days based on the instrumental observations using the LS8000 lightning detector. The method is based on the interrelation between the area of the territory and the probability of lightning detection during a year. Carried out is the comparative analysis of the results of thunderstorm activity registration based on the data of instrumental measurements and observations at weather stations.

When the Danish Meteorological Institute (DMI) was established in 1872 it took over the responsibility of meteorological observations in Iceland. Prior to that time, the observations were in the hands of enthusiastic individuals, in some cases in close contact with the international scientific community. The original data compiled by these latter observers are kept at the Manuscript Section of the Icelandic National Library and in the Archives of the Icelandic Meteorological Office. Much of this material was gradually delivered to Iceland (along with other documents from official Danish archives) after the formal independence of Iceland in 1918. This paper presents an overview of instrumental observations available from the pre-1872 era. The oldest such observations that have been found were made in 1749 to 1751 and in 1763. The temporal density increases after 1775, and from 1822 there is at least one instrumental observation to be found on each and every day, somewhere in Iceland. During the period 1776 to 1822 there are many gaps, some only short, others long; with the longest from late 1814 to mid 1820. During this last gap almost no instrumental records have been found. The quality of the observations is very variable, but generally they seem to be at least internally consistent, and will certainly become an important addition to the knowledge of the climate and climatic variability of the Northeast Atlantic region. A large part of the data are available in digital format. The present study gives a richer and more comprehensive view of the meteorological activities in Iceland during the “Early Instrumental Period” (EIP), than previously available. It includes a summary of the early history of meteorological measurements in Iceland. Weather diaries without quantitative measurements are outside the scope of this paper.

In accordance with the contract № 1881 dated 30.11.2018 between the State Enterprise «National Atomic Energy Generating Company "Energoatom"» and the National Center for Management and Testing of Space Means, specialists of the Main Center of Special Control carried out work on the analysis of the results of instrumental seismic observations on a permanent seismic network Rivne NPP monitoring. The article presents information about the organization and arrangement of the seismic monitoring network in the Rivne NPP area, as well as the results of the analysis of interfering conditions and the influence of microseims of different order on the ability of recording useful signals on the network elements. According to the records obtained using seismic sensors installed in instrument wells and on the day surface, the average values of the microseismic background at the checkpoints were calculated. In the course of instrumental observations, local, regional and tele-seismic events of different nature and energy levels were recorded. The vast majority of recorded earthquakes are located in Romania in the Vrancea seismic zone, Poland and southern Belarus.According to the results of seismic record processing, the intensity of shaking in the region of Rivne NPP was determined and conclusions were made regarding the necessity of changes of the initial data for the assessment of the seismic stability of the RNPP site.

Instrumental observations from Dejima (Nagasaki), Japan, taken under the responsibility of the Dutch, covering the periods 1819-28, 1845-58, and 1871-78, have been recovered. The Dejima series overlaps by six months the modern Nagasaki Observatory series, which covers 1878-present. The recovered data extend the start of the instrumental Japanese series back from 1872 to 1819, leaving major gaps during 1829-44 and 1859-71.

Daily pressure observations recorded by William Derham (1657–1735) at Upminster, Essex (near London), from 1697 to 1706 and 1708 have been corrected, converted to modern units and the Gregorian calendar, and adjusted for homogeneity. These pressure readings have been compared with previously published contemporary observations from Paris, and the two sets of early instrumental data used to calculate a daily series of the pressure difference between Paris and London. Frequency analysis of the daily series reveals that reversals of the south–north pressure gradient and easterly winds were more common from 1697 to 1708 than during the 1990s. Monthly mean values of Paris–London pressure differences have been compared with previously published monthly mean reconstructed surface pressure maps and to a reconstructed North Atlantic Oscillation (NAO) index. There is a good agreement between the strength and direction of monthly mean flow between London and Paris estimated from the circulation maps and the sign and magnitude of the Paris–London westerly flow index, but the correlation between the Paris–London index, known to be a good proxy for European zonal circulation, and the reconstructed NAO index, is low (0.2). Correlations between the monthly mean Paris–London zonal circulation index and central England temperatures suggest a strong relationship during winter and late summer from 1697 to 1708. The meticulous daily instrumental observations and the monthly and seasonal climate descriptions of Derham, his collection of instrumental observations and climatic descriptions from contemporary observers throughout Europe, and his early theories on the causes of climate change make his publications a valuable source of information for studies on climate during the early instrumental period. It is hoped that more of Derham's papers related to weather and climate may eventually come to light. Copyright © 2001 Royal Meteorological Society.

The article presents the results of the assessments of the current state of instrumental seismic observations in reservoirs used in seismically active regions of Uzbekistan. The assessment of the current state of continuous instrumental seismological observations was made at the Charvak, Andijan, Gissarak and Tupolang reservoirs used in seismically active regions of Uzbekistan. The estimates of the state of instrumental observations at large reservoirs in Eastern and Southern Uzbekistan are summarized. The results of expeditionary research are presented, as well as the possibilities for improving existing systems. The results obtained are of a practical nature, in which the directions for improving the existing stationary seismometric system in large reservoirs are determined. The results can also be used to provide and create permanent seismic monitoring systems in reservoirs.

There is a significant lack of historical climate data in the Southern Hemisphere compared to the northern latitudes. To address this data scarcity and to improve understanding of regional climate variability, historical instrumental observations were recovered for southeastern Australian (SEA) for the 1788–1859 period. Instrumental observations of temperature, atmospheric pressure, rainfall and raindays were rescued from 39 archival sources, and examined to identify observer biases and inhomogeneities. The rescued data provide continuous information on SEA climate variability from 1826 to 1859, with short periods of observations identified between 1788–1791, 1803–1805 and 1821–1824. Quality control and homogenization of each data source indicates that the historical observations successfully capture regional interannual climate variability. The historical records exhibit high correlations between neighbouring observations and related climate variables. The instrumental observations also display very good agreement with documentary climate reconstructions, further verifying their quality. As an example of how this new historical dataset may be used, regional averages of the observations were calculated to estimate interannual climate variability across SEA from 1826 to 1859. Prolonged dry conditions were identified in various parts of the region during 1837–1843 and 1845–1852, while wet conditions were noted from 1836 to 1838, primarily in southern SEA. Anomalously cold periods were also identified in 1835–1836 and 1848–1849, in general agreement with temperature reconstructions from other regions of the Southern Hemisphere. This new dataset provides a valuable source of subdaily to monthly information on SEA climate variability for future climate analysis, palaeoclimate reconstruction verification and historical studies.

Cataclasites are a characteristic rock type found in drill cores from active faults as well as in exposed fossil subduction faults. Here, cataclasites are commonly associated with evidence for pervasive pressure solution and abundant hydrofracturing. They host the principal slip of regular earthquakes and the family of so-called slow earthquakes (episodic slip and tremor, low to very low frequency earthquakes, etc.). Slip velocities associated with the formation of the different types of cataclasites and conditions controlling slip are poorly constrained both from direct observations in nature as well as from experimental research. In this study, we explore exposed sections of subduction faults and their dominant microstructures. We use recently proposed constitutive laws to estimate deformation rates, and we compare predicted rates with instrumental observations from subduction zones. By identifying the maximum strain rates using fault scaling relations to constrain the fault core thickness, we find that the instrumental shear strain rates identified for the family of “slow earthquakes” features range from 10−3s−1 to 10−5s−1. These values agree with estimated rates for stress corrosion creep or brittle creep possibly controlling cataclastic deformation rates near the failure threshold. Typically, pore-fluid pressures are suggested to be high in subduction zones triggering brittle deformation and fault slip. However, seismic slip events causing local dilatancy may reduce fluid pressures promoting pressure-solution creep (yielding rates of <10−8 to 10−12s−1) during the interseismic period in agreement with dominant fabrics in plate interface zones. Our observations suggest that cataclasis is controlled by stress corrosion creep and driven by fluid pressure fluctuations at near-lithostatic effective pressure and shear stresses close to failure. We posit that cataclastic flow is the dominant physical mechanism governing transient creep episodes such as slow slip events (SSEs), accelerating preparatory slip before seismic events, and early afterslip in the seismogenic zone.

In the 1970s and 1980s, the semi-arid Sahel, the southern edge of the Sahara Desert, experienced spatially uniform drought, from the Atlantic Ocean to the Red Sea. The recovery that ensued is projected to continue in the center and east, leaving the west out. We show that these two patterns—uniform variation and east-west contrast—are present in instrumental observations and in simulations with constant or time-varying external forcing. Uniform variation is amplified by 20th century external forcing, while a global warming–induced strengthening of the monsoon seeds the east-west contrast. This contrast is deepened by a mid-21st century transition to a North Atlantic cooling relative to the global tropical oceans, which affects the western Sahel most strongly because it is immediately adjacent to the North Atlantic, leading to a divergence in outcomes—between a progressively wetter central and eastern Sahel and an abruptly drier western Sahel—that is unparalleled in instrumental observations.

Using the data of long-term surveying at the Saranovsky chrome iron ore deposit, movements of rock mass were analyzed with a view to identifying potential early signs of ground surface collapse. The research findings are unique as one of the instrumental observation series was accomplished on the eve of the ground surface sinking above non-backfilled voids of earlier stoping. It was found that the test area experienced vertical alternating movements, and sinking was preceded by upheaval of ground surface. However, the further analysis revealed no clear cause-and-effect between the event and insufficiency of its study. The subsequent research identified a local cluster of rock mass subsidences at gradually increasing velocities, which showed up a few years before the sink appeared on ground surface above its initiation source. The absence of this cluster zone in the period before the collapse is explained by the damage of check points in this site. Finally, the conclusion is drawn that in certain geological conditions, deformation processes are localized and manifest no visible signs of impact on the enclosing rock mass and ground surface. Manifestations of these processes from the instrumental observations concentrate directly in the local area of their development, which should be taken into account in the analysis and prediction of movements. It is emphasized that the existing and new criteria of hazardous deformation processes should be corrected and updated for geomechanical monitoring of mineral mining objects.

A comprehensive data base of about 17000 historical and recent earthquakes has been established for the Central American region, based on existing research and reports from Guatemala, El Salvador, Honduras, Nicaragua, Costa Rica and Panama. The catalog includes known damaging historic earthquakes, as well as the more important of the recent data, including both macroseismic and instrumental observations. The catalog starts in the beginning of the 16th century and is limited to macroseismic data (reeported phenomena and associated damage) until 1902, while it for the time since then contains both macroseismic and instrumental observations. Recent local network solutions are normally included only for events above magnitude 3.5.The new catalog is considered to be reasonable complet for earthquakes with magnitudes MS ≥5.5 back to around year 1900, and for MS ≥7 back to around year 1820, and it should have the capabilities of further assisting the ongoing efforts towards a more reliable evaluation of the seismogenic potentials in the region. The catalog infomation has been used in this paper for developing new relations between body wave magnitude mb and surface wave magnitude MS, between mb and local magnitude ML, and between MS and ML. New relations have also been developed between mb, MS and ML and maximum intensity Imax, between ML and felt radius, and between ML and felt area for intensity levels between III and VIII. Such relations are potentially important for a further development and improvement of the magnitude assessments for both newer and older earthquakes, as well as for many questions related to earthquake engineering.

Establishing a high-resolution surface sediment chronology with multiple dating methods – Testing 137Cs determination with Nurmijärvi clastic-biogenic varves

Monitoring condition of hydrotechnical structures conducted to ensure the management of the rational and safe operation of the waterworks. Based on the results of regular interconnected control observations of the state of the GTS, a database of observations is compiled. On its basis, analysis and evaluation of the forecast of the development of negative processes at the facility and development of recommendations for their overcoming and elimination of identified violations are carried out; prevention of emergency situations; creation of conditions for safe operation. Monitoring safety GTS carried out on the example of hydrotechnical structures of the blocking regulatory structure of the Aleksandrovogai reservoir in the Saratov region. The main quantitative and qualitative indicators and their criteria values are given. It is recommended that during operation, visual observations be carried out daily, instrumental observations - at least 1 time in 3 years, in addition to this, at least once every two weeks to inspect the hydraulic structures with the results recorded in the appropriate journal. Systematic visual observations should be supplemented by pre-flood and post-flood inspections of structures, as well as unscheduled inspections carried out after extreme events accompanied by damage to structures. Particular attention should be paid to observing the filtration regime in the body and base of the dam, the state of fastening of the inlet and outlet heads, closures and pipelines of the outlet structure.

This paper presents the results of the\nanalysis of possible existence of nine near-Earth\nmeteorite-producing groups in asteroidal orbits, consisting\nof sporadic fireballs from the IAU MDC 2007 database,\nsporadic meteors from the SonotaCo database, meteorites\n– namely, L5, L6 and H4-H6 ordinary chondrites and an\nureilite, for which atmospheric and orbital parameters are\nknown from instrumental observations – and their\nplausible parent bodies, that is, near-Earth asteroids\n(NEAs). Orbits of the selected members of meteorite-\nproducing groups were classified as asteroidal according\nto the Tisserand parameter T J > 3.1.\nIn order to test the link between meteorite-producing\ngroups in asteroidal orbits and their plausible parent\nbodies, we carried out an investigation into the possible\nexistence of some known NEAs that move in similar\norbits. Based on the orbital similarity, determined using\nthe Drummond (D D ) and Southworth & Hawkins (D SH )\norbital similarity criteria, some associations between the\nidentified NEAs, known meteorites in asteroidal orbits\nand small, as well as meteorite-dropping, meteoroids have\nbeen suggested. As a result, several meteorite-dropping\nsporadic fireballs and small meteors, whose orbits are\ncurrently similar to the orbits of known meteorites, have\nbeen detected and reckoned as possible members of the\ngroups in asteroidal orbits; their plausible source regions\nhave also been considered.

The paper reports the main results of the EU project Millennium in the Mediterranean area over the last 500 years. It analyses a long series of temperature from Portugal, Spain, France, Italy and Greece. The series are obtained by combining indices from documentary sources from AD 1500 to the onset of regular instrumental observations. There is an ongoing discussion regarding the proper way of combining documentary and instrumental data and how to translate accurately the conventional indices from − 3 to + 3 into modern units, i.e. degree Celsius. This paper produces for the first time a number of early instrumental observations, in some cases (i.e. Italy and France) covering 350 years, including thereby the earliest regular observations after the invention of the thermometer. These Mediterranean data show that anomalous temperatures usually had only a locally limited effect, while only few extreme events had a widespread impact over the whole region, such as the summer of 2003. During the period from 1850 to the present day, the Mediterranean temperature anomaly was close to the Northern Hemisphere in spring and summer, while it was warmer in autumn and winter. Compared with the long-term instrumental records (i.e. 1655 onwards), the recent warming has not exceeded the natural past variability characterized by heating–cooling cycles with no significant long-term trends.