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1.
Kamchatka and the Kuril Islands (the Kuril-Kamchatka arc) make up the region of highest seismicity in Russia. About 80% of Russian earthquakes occur there, but a mere handful of three seismographic stations had been in operation until the autumn of 1957. On September 2, 1957, the Seismological Team of the Pacific Multidisciplinary Geologic and Geophysical Expedition, Institute of Physics of the Earth, USSR Acad. Sci. set foot on Iturup I, South Kuril Is. to do research for the International Geophysical Year program during 1957–1959, and began detailed seismological investigations in the Kuril-Kamchatka arc. During the subsequent 50 years, six organizations of the USSR/Russian Academy of Sciences conducted and developed this research in the Kuril Is. and Kamchatka. We review previous seismic expeditionary studies, which were carried out in other regions of the USSR from 1949 to 1957. The beginning of the detailed seismological investigations for the Kuril-Kamchatka arc is described, providing brief information on how this research was organized, as well as on the researchers involved, their lines of research, and the development of the extensive and comprehensive studies carried out in 1957–2007, along with some of their leading results. These results include the study of seismicity, its patterns, geodynamics, deep structure, upper mantle properties, the relationships between seismicity and volcanism, and successful long-term earthquake forecasts, among other subjects.  相似文献   

2.
Results are reported from continuous long-term earthquake prediction work for the Kuril-Kamchatka island arc using the patterns of seismic gaps and the seismic cycle. A five-year forecast (April 2006 to April 2011) for all portions of the Kuril-Kamchatka seismogenic zone is presented. According to this, the most likely locations of future M ≥ 7.7 earthquakes include the Petropavlovsk-Kamchatskii area where the probability of an M ≥ 7.7 earthquake causing ground motions of intensity VII to IX in the town of Petropavlovsk-Kamchatskii is 48% for 2006–2011, and the area of Onekotan I. and the Middle Kuril Islands where the probability of an M ≥ 7.7 earthquake was estimated as 26.7%. The forecast was fulfilled on November 15, 2006, when an Ms= 8.2, Mw = 8.3 earthquake occurred in the Middle Kuril Islands area. An updated long-term forecast is presented for the Kuril-Kamchatka arc for the period from November 2006 to October 2011. These forecasts provide good reasons to enhance seismic safety by strengthening buildings and structures in Kamchatka.  相似文献   

3.
We consider the identification and diagnostics of active and potentially active volcanic features (regional zones of cinder cones, fields sheet volcanism, fields of concentrated multivent extrusive volcanism, calderas, and underwater eruption centers in the sea) in the Kuril-Kamchatka island arc and in the Commander Islands link of the Aleutian island arc, as well as the condition of this region as of late 2007. We have identified and examined three periods in the research of active and potentially active volcanic features in the region: the early (1697–1934), the new (1935–1962), and the most recent, still in progress (1963 until today). We provide a new definition of the term “active volcano,” which is scientifically well-grounded, for the first time here. We present modified (compared with those available until now) catalogs of active and potentially active volcanic forms in Kamchatka and the Kuril Islands. For typical multieruption volcanoes now in phase I (the active) and II (the passive) of their evolution, we provide long-term forecasts of the character and parameters of future eruptions and the associated volcanic hazard.  相似文献   

4.
This paper discusses results from ongoing research on long-term earthquake prediction for the Kuril–Kamchatka island arc based on the concepts of seismic gaps and the seismic cycle. We developed a forecast for the next 5 years (April 2016 through March 2021) for all segments of the earthquake-generating zone along the Kuril–Kamchatka arc. The 20 segments of the arc were analyzed to develop forecasts of the appropriate phases of the seismic cycle, a normalized parameter of the rate of small earthquakes (A10), the magnitudes of moderate earthquakes that are expected with probabilities of 0.8, 0.5, and 0.15, the maximum expected magnitudes, and the probabilities of great (M ≥ 7.7) earthquakes. We discuss the seismic process in the Kuril–Kamchatka earthquake-generating zone before and after the deep-focus May 24, 2013 M 8.3 earthquake in the Sea of Okhotsk. The results corroborate the high seismic hazard in the area of Petropavlovsk-Kamchatskii and the urgent need for continuing with and expanding the ongoing work of seismic retrofitting and seismic safety enhancement. We quote practical results from applications of the method during 30 years.  相似文献   

5.
We used the data on the activity of volcanoes in Kamchatka and the North Kuril Islands for the period from 1840 to early 2013 to identify the most significant cyclic components. The resulting periodicities were compared with the recurrence spectrum for great (M ≥ 7.7) earthquakes in the Kuril-Kamchatka region for 1841–2012. We detected 52.8–54.0, 8.58, and 5.72-year cycles, which are common both to seismicity and to volcanic activity. The first interval is close to the three times the value of the 18.613-year lunar rhythm (55.84 years). The 8.58 and 5.72-year periodicities seem to be controlled by solar activity variations and are the second and third harmonics in the 17.15-year cycle. This cycle and its harmonics are used for long-term prediction of great (M ≥ 7.7) earthquakes in the Kuril-Kamchatka region as a whole. It was concluded that the existing increased hazard of great earthquake occurrence in the Kuril-Kamchatka region will last until February 2016 (a 40% probability of a great earthquake during that period). In addition, the long-period phase of increased seismic hazard will last until 2027 with the probability of great earthquakes being 1.6 times the long-term average value.  相似文献   

6.
Kamchatka and the Kuril Islands are home to 36 active volcanoes with yearly explosive eruptions that eject ash to heights of 8 to 15 km above sea level, posing hazards to jet planes. In order to reduce the risk of planes colliding with ash clouds in the north Pacific, the KVERT team affiliated with the Institute of Volcanology and Seismology of the Far East Branch of the Russian Academy of Sciences (IV&S FEB RAS) has conducted daily satellite-based monitoring of Kamchatka volcanoes since 2002. Specialists at the IV&S FEB RAS, Space Research Institute of the Russian Academy of Sciences (SRI RAS), the Computing Center of the Far East Branch of the Russian Academy of Sciences (CC FEB RAS), and the Far East Planeta Center of Space Hydrometeorology Research (FEPC SHR) have developed, introduced into practice, and were continuing to refine the VolSatView information system for Monitoring of Volcanic Activity in Kamchatka and on the Kuril Islands during the 2011–2015 period. This system enables integrated processing of various satellite data, as well as of weather and land-based information for continuous monitoring and investigation of volcanic activity in the Kuril–Kamchatka region. No other information system worldwide offers the abilities that the Vol-SatView has for studies of volcanoes. This paper shows the main abilities of the application of VolSatView for routine monitoring and retrospective analysis of volcanic activity in Kamchatka and on the Kuril Islands.  相似文献   

7.
This paper presents measurements for the 1987–2016 period; these include inclined distances and elevations between geodetic monuments in the deformation site in the Ust’-Kamchatsk area. These data are important for future investigators, because measurements can be made in the distant future in order to compare with the respective past values. This area has been accumulating deformation for the last 27 years along the direction perpendicular to the Kuril–Kamchatka Benioff zone, reaching values of approximately (5?10) × 10–6. The compression involves a northwest tilt of the ground surface.  相似文献   

8.
This work presents the project of the first stage of implementation of the integrated instrumental system of volcanic activity monitoring in Kamchatka and the Kuril Islands. The system of monitoring was designed for the purpose of ensuring public safety, aviation safety, and reducing economic losses caused by volcanic eruptions. The most active and dangerous volcanoes in Kamchatka (North and Avacha groups of volcanoes) and the Kuril Islands (volcanoes on the islands of Kunashir and Paramushir) are of first priority for monitoring. For this purpose, special observation points are planned to be installed on the volcanoes. The system of monitoring will include a complex of observations (broadband seismic station with a large dynamic range, tiltmeter, devices for gas, acoustic, and electromagnetic observations, and video camera). All the data will be passed to information processing centers in real time. New methods and algorithms of automatic and automated identification of the volcanic activity level and the probabilistic volcano hazard assessment have been developed.  相似文献   

9.
This paper reviews the Kamchatka seismicity for a 50-year period of observation. These data were used to carry out a regionalization of Kamchatka’s seismic volume and adjacent areas. In all, ten zones were identified with differing activities and origins of seismicity. A comparative analysis was carried out for the seismicity in the more active zones. We found significant differences between the structures of the southern and the northern segment in the Kamchatka part of the Kuril-Kamchatka subduction zone. Seismological data corroborated a relationship between the subduction zone and the underthrusting of the Pacific plate under the Eurasian plate. These data from the 50-year period of observation helped identify a new Koryak seismic belt that encompasses the northwestern coast of the Bering Sea. We provide a brief review of macroseismic effects due to the most significant earthquakes for the 1962–2010 period.  相似文献   

10.
Results are reported from the ongoing 2007–2008 work using the method of long-term earthquake prediction for the Kuril-Kamchatka arc based on the patterns of seismic gaps and the seismic cycle. This method was successful in predicting the M S = 8.2 Simushir I. (Middle Kuril Is.) earthquake occurring in the Simushir I. area on November 15, 2006. An M S = 8.1 earthquake occurred in the same area on January 13, 2007. We consider the evolution of the seismic process and determine the common rupture region of the two earthquakes. The sequence of M ≥ 6.0 aftershocks and forecasts for these are given. We provide a long-term forecast for the earthquake-generating zone of the Kuril-Kamchatka arc for the next five years, April 2008 to March 2013. Explanations are given for the method of calculation and prediction. The probable locations of future M ≥ 7.7 earthquakes are specified. For all segments of the earthquake-generating zone we predict the expected phases of the seismic cycle, the rate of low-magnitude seismicity (A10), the magnitudes of moderate-sized earthquakes to be expected, with probabilities of 0.8, 0.5, and 0.15, their maximum possible magnitudes, and the probabilities of occurrence of great (M ≥ 7.7) earthquakes. The results of these forecasts are used to enhance seismic safety.  相似文献   

11.
Collision orogeny at arc-arc junctions in the Japanese Islands   总被引：1，自引：0，他引：1  
Gaku  Kimura 《Island Arc》1996,5(3):262-275
Abstract In the Japanese Islands, collision tectonics are operating at arc-arc junctions in three regions: Hokkaido, Central Japan and Kyushu. Hokkaido is situated at the junction of the Kuril and Northeast Japan Arcs. The Kuril fore arc sliver collides with the Northeast Japan Arc, and the lower crust of the Kuril Arc thrusts upon the fore arc of the Northeast Japan Arc in Hokkaido. Outcrops of the lower crust are observed in the Hidaka Mountains in the fore arc of the junction area. Central Japan is in the juncture area among the Northeast Japan, Izu-Bonin, and Southwest Japan Arcs. The Izu-Bonin arc is colliding against the Honshu mainland, which has been bent by the collision. Kyushu is a juvenile collision area between the Southwest Japan and Ryukyu Arcs. The fore arc of the Southwest Japan Arc is starting to underthrust beneath the Kyushu islands along the Bungo Strait, where shallow seismicity within the crust is active in terms of the collision. Collision tectonics are observed at most of the arc-arc junctions in the circum-Pacific orogenic belts and may be an important process contributing to the relatively rapid growth of new continental crust in subduction zones.  相似文献   

12.
This study is concerned with seismicity variations in Kamchatka and the Kuril Islands for the period 1962–2009; the effects of large earthquakes on the seismicity of adjacent areas are taken into account. The 1997 Kronotskii earthquake was followed by seismicity decreases in most areas over Kamchatka, which is presumably related to decreased tectonic stresses. After the 2007 Simushir earthquake synchronization and periodicities in seismicity were identified, indicating increased instabilities and the likelihood of a large event in Kamchatka in the near future. The instability of seismic regions is discussed within the framework of the theory of nonequilibrium dynamical systems. We suggest successive phases in the occurrence of seismological precursors.  相似文献   

13.
According to the concepts of accretionary tectonics, the region of interest was a dynamically evolving active continental margin during Mesozoic/Cenozoic time; this is reflected in the generation of nine volcano-plutonic belts that successively evolved from northwest to southeast. Most of these evolved in parallel with the present-day location of the Kuril-Kamchatka deep-sea trench: the Late Jurassic/Early Cretaceous Uda-Murgali belt (UMVB) the Uyandina-Yasachnaya (UYVB), the Oloi belt (OVB), the Late Cretaceous/Paleogene Okhotsk-Chukchi belt (OChVB), the Late Cretaceous/Paleogene East-Sikhote-Alin’ belt (ESVB), the Eocene/Oligocene Koryak-West-Kamchatka belt (KWKVB), the Oligocene/Quaternary Central Kamchatka belt (CKVB), and the Pliocene/Quaternary East Kamchatka belt (EKVB). The successively younger age of the volcanic belts since the Early Cretaceous is in correspondence with the displacement of the volcanic arc-trench system toward the Pacific Ocean. Apart from the above-mentioned volcanogenic belts, the Omolon craton terrane also contains the pre-accretionary Devonian Kedon marginal volcanogenic belt (KVB). All the volcanogenic belts and the surrounding perivolcanic zones of tectono-magmatic activation (TMA) form the world-largest metallogenic province with a polychronous volcanogenic-plutonogenic metallization of various compositions.  相似文献   

14.
We consider the key features in the responses of magnetic tippers and MTS curves to the sharp contrast in electric conductivity at the interface between the land and the sea waters of the Sea of Okhotsk and the Pacific bounding Kamchatka. The zones with different intensity of the coast effect are revealed. Stronger manifestations of the effect are found to occur in the East Kamchatka, which is related to the induction effects of the electric currents concentrated in the Kuril-Kamchatka trench. Indentation of the coastline resulted in the appearance of three-dimensional (3D) effects in the magnetotelluric field of the eastern Kamchatka. These effects in the variations of the geomagnetic field are vanishing with an increasing period, giving room to low-frequency effects in the MT field, which are associated with the flow of electric currents around Kamchatka (the around-flow effect). It is shown that the transverse MTS curves over the entire region of Kamchatka suffer from the S effect at low frequencies and do not characterize the deep geoelectric structure. Only in the middle segments of the West and Central Kamchatka, the longitudinal MTS curves are weakly subjected to the induction effects and thus reflect the distribution of the deep electric conductivity. On the eastern coast of Kamchatka both the longitudinal and transverse MTS curves are strongly distorted by the 3D effects caused by the abundant capes and bays. The interpretation of MTS data in this region should necessarily invoke the 3D modeling of an MT field.  相似文献   

15.
The Bannaya–Karymshina area is situated in southern Kamchatka west of the East Kamchatka Volcanic Belt in the backarc part of the Kuril–Kamchatka island arc. The area is unique in that it contains abundant ejecta of calc-alkaline, acid, mostly ignimbrite, volcanism for a period of 4 Ma. Three rock complexes can be identified with rhyolitic and rhyodacitic compositions: Middle Pliocene ignimbrites, crystalloclastic tuffs of Eopleistocene age that fill in the Karymshina caldera, and Early Pleistocene intrusions. All of these are composed of rocks with normal total alkalinity, while the concentration of potassium places them at the boundary between moderate and high-potassium rocks. We sought to determine the composition of primary acid melts by studying the composition of the silicate phase in homogeneous melt inclusions that were conserved in quartz phenocrysts hosted by volcanic rocks of varying ages. Practically all the melt inclusions we analyzed show increased total alkalies and are in the class of trachyrhyodacites and trachyrhyolites, with the varieties of the highest alkali content being alkaline rhyolites and comendites; the concentration of K2O classifies them as subalkaline rocks; one also notes the increased alumina of the acid melts. The compositions and spatial locations of the melt inclusions in quartz phenocrysts provide evidence of a three-phase crystallization in magma chambers at different depths. According to the experimental data, the quartz phenocrysts crystallized in a water-saturated melt at pressures of 0.1 to 3.5 kbars.  相似文献   

16.
The manner in which the dynamics of geoelectric earth inhomogeneities can be studied using receiving lines oriented in different directions at a single site is considered. It is shown that the presence of a local geoelectric inhomogeneity allows monitoring the state of electric conductivity in the earth by observation of the telluric tensor. We quote results from long-continued monitoring of the electrotelluric tensor in Kamchatka. The tensor’s behavior showed an appreciable anomaly, which may have been related to great (magnitude 8.2 and 8.3) earthquakes in the Kuril-Kamchatka region.  相似文献   

17.
The comparative analysis of the Earth’s surface deformations measured by ground-based and satellite geodetic methods on the regional and zonal measurement scales is carried out. The displacement velocities and strain rates are compared in the active regions such as Turkmenian–Iranian zone of interaction of the Arabian and Eurasian lithospheric plates and the Kamchatka segment of the subduction of the Pacific Plate beneath the Okotsk Plate. The comparison yields a paradoxical result. With the qualitatively identical kinematics of the motion, the quantitative characteristics of the displacement velocities and rates of strain revealed by the observations using the global navigational satellite system (GNSS) are by 1–2 orders of magnitude higher than those estimated by the more accurate methods of ground-based geodesy. For resolving the revealed paradoxes, it is required to set up special studies on the joint analysis of ground-based and satellite geodetic data from the combined observation sites.  相似文献   

18.
This is a review of the geodetic monitoring of the horizontal component of recent crustal movements (RCMs) in Kamchatka and the Commander Islands for the period 1979–2007. Examples are provided of the RCMs recorded in Kamchatka and the Commander Islands for the period 1997–2007 by the Kamchatka regional GPS network (KAMNET) set up by workers at the Kamchatka Branch of the RAS Geophysical Service (KB GS RAS) in collaboration with the Institute of Volcanology and Seismology of the Far East Division of the Russian Academy of Sciences to study the geodynamic processes that are occurring in the Kamchatka subduction zone. An interpretation of examples of recorded RCMs is given.  相似文献   

19.
This paper considers the results from seismic investigations of the Kuril-Kamchatka trench (KKT) using continuous seismic profiling (CSP), the common-depth point (CDP), and deep seismic sounding (DSS). The outcome is an approximate 2D seismic model that reflects the overall structure of the landward trench slope for most of the KKT, with the greatest departure of the data from the model being for the middle Kuril Islands area. A deep-seated fault has been identified in the upper part of the slope 60–80 km from the trench axis, with the fault being traceable throughout the depth interval between the seafloor and the bottom of the crust. In the portion between the fault and the trench axis the seismic velocities are lower, the gradient higher, and the crust thins rapidly seaward. The sediment thickness on the landward slope varies along the trench, reaching the maximum off the southern Kuril Islands. The structural variations along the KKT show a broad correlation with the behavior of geophysical fields and seismicity, which seems to be an expression of global tectonic processes.  相似文献   

20.
We consider the results from the ongoing 2010–2011 work on long-term earthquake prediction for the Kuril-Kamchatka arc based on the pattern of seismic gaps and the seismic cycle. We develop a forecast for the next 5 years, from September 2011 to August 2016, for all segments of the Kuril-Kamchatka arc earthquake-generating zone. For 20 segments we predict the appropriate phases of the seismic cycle, the normalized rate of small earthquakes (A10), the magnitudes of moderate earthquakes to be expected with probability 0.8, 0.5, and 0.15, and the maximum possible magnitudes and probability of occurrence for great (M ≥ 7.7) earthquakes. This study serves as another confirmation that it is entirely necessary to continue the work in seismic retrofitting in the area of Petropavlovsk-Kamchatskii.  相似文献   

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