Deep structure of South Kamchatka according to geophysical data
Differences have been discovered in the deep structures of North and South Kamchatka, which raises a question about a boundary between these regions. This problem has been studied on the basis of the seismologic, inverse seismic tomographic (P-waves) and geoelectrical data obtained in recent years,...
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| Format: | Article |
| Language: | English |
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Russian Academy of Sciences, Siberian Branch, Institute of the Earth's crust
2018-12-01
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| Series: | Геодинамика и тектонофизика |
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| Online Access: | https://www.gt-crust.ru/jour/article/view/670 |
| _version_ | 1797855731885539328 |
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| author | Yu. F. Moroz L. I. Gontovaya |
| author_facet | Yu. F. Moroz L. I. Gontovaya |
| author_sort | Yu. F. Moroz |
| collection | DOAJ |
| description | Differences have been discovered in the deep structures of North and South Kamchatka, which raises a question about a boundary between these regions. This problem has been studied on the basis of the seismologic, inverse seismic tomographic (P-waves) and geoelectrical data obtained in recent years, as well as the information on magnetometry, gravimetry, tectonics and magmatism of the study area. Comprehensive analysis of the geological and geophysical data shows differences in the structure of the crust and upper mantle in North and South Kamchatka and common features of the deep structures of South Kamchatka and the Kuril Islands. A presumed boundary between North and South Kamchatka is related to the zone of transverse deep faults crossing the peninsula. It is evidenced by P-wave velocity anomalies at different levels of the lithosphere. This fault zone is associated with a change in the geometry and strike of the high-velocity focal layer, and reflected in the modern tectonic plan as the Petropavlovsk-Malkinsky zone of transverse dislocations. In this zone, the Avacha-Koryak group of modern volcanoes is also NW-oriented. We propose a geoelectric model showing the depths along the profile constructed across the zone. In its deep part, the model includes sub-vertical anomalies of increased electrical conductivity. The anomalies are related to deep faults. Increased electrical conductivity may be due to the presence of magmatic melts feeding volcanoes. The results obtained in our study give evidence of the common features of the deep structures of South Kamchatka and the Kuril island arc and demonstrate the differences between the deep structures of North and South Kamchatka, being separated by the zone of faults, which may penetrate into the upper mantle. It is suggested that the identified features in the South Kamchatka structure are due to deep processes taking place not only at the side of the Pacific Ocean, but also at the southern margins of the Sea of Okhotsk. These findings are of interest for geodynamics, volcanology, tectonics and other Earth sciences. |
| first_indexed | 2024-04-09T20:28:11Z |
| format | Article |
| id | doaj.art-e731fdff362d4a80bfc984cf0e100419 |
| institution | Directory Open Access Journal |
| issn | 2078-502X |
| language | English |
| last_indexed | 2024-04-09T20:28:11Z |
| publishDate | 2018-12-01 |
| publisher | Russian Academy of Sciences, Siberian Branch, Institute of the Earth's crust |
| record_format | Article |
| series | Геодинамика и тектонофизика |
| spelling | doaj.art-e731fdff362d4a80bfc984cf0e1004192023-03-30T20:08:04ZengRussian Academy of Sciences, Siberian Branch, Institute of the Earth's crustГеодинамика и тектонофизика2078-502X2018-12-01941147116110.5800/GT-2018-9-4-0387385Deep structure of South Kamchatka according to geophysical dataYu. F. Moroz0L. I. Gontovaya1Institute of Volcanology and Seismology, Far East Branch of RAS; Geological Institute, Siberian Branch of RASInstitute of Volcanology and Seismology, Far East Branch of RASDifferences have been discovered in the deep structures of North and South Kamchatka, which raises a question about a boundary between these regions. This problem has been studied on the basis of the seismologic, inverse seismic tomographic (P-waves) and geoelectrical data obtained in recent years, as well as the information on magnetometry, gravimetry, tectonics and magmatism of the study area. Comprehensive analysis of the geological and geophysical data shows differences in the structure of the crust and upper mantle in North and South Kamchatka and common features of the deep structures of South Kamchatka and the Kuril Islands. A presumed boundary between North and South Kamchatka is related to the zone of transverse deep faults crossing the peninsula. It is evidenced by P-wave velocity anomalies at different levels of the lithosphere. This fault zone is associated with a change in the geometry and strike of the high-velocity focal layer, and reflected in the modern tectonic plan as the Petropavlovsk-Malkinsky zone of transverse dislocations. In this zone, the Avacha-Koryak group of modern volcanoes is also NW-oriented. We propose a geoelectric model showing the depths along the profile constructed across the zone. In its deep part, the model includes sub-vertical anomalies of increased electrical conductivity. The anomalies are related to deep faults. Increased electrical conductivity may be due to the presence of magmatic melts feeding volcanoes. The results obtained in our study give evidence of the common features of the deep structures of South Kamchatka and the Kuril island arc and demonstrate the differences between the deep structures of North and South Kamchatka, being separated by the zone of faults, which may penetrate into the upper mantle. It is suggested that the identified features in the South Kamchatka structure are due to deep processes taking place not only at the side of the Pacific Ocean, but also at the southern margins of the Sea of Okhotsk. These findings are of interest for geodynamics, volcanology, tectonics and other Earth sciences.https://www.gt-crust.ru/jour/article/view/670seismologyseismic tomographygeoelectricsseismic velocity rateelectrical conductivityearthquakevolcanohydrothermal solutionmagmatic melt |
| spellingShingle | Yu. F. Moroz L. I. Gontovaya Deep structure of South Kamchatka according to geophysical data Геодинамика и тектонофизика seismology seismic tomography geoelectrics seismic velocity rate electrical conductivity earthquake volcano hydrothermal solution magmatic melt |
| title | Deep structure of South Kamchatka according to geophysical data |
| title_full | Deep structure of South Kamchatka according to geophysical data |
| title_fullStr | Deep structure of South Kamchatka according to geophysical data |
| title_full_unstemmed | Deep structure of South Kamchatka according to geophysical data |
| title_short | Deep structure of South Kamchatka according to geophysical data |
| title_sort | deep structure of south kamchatka according to geophysical data |
| topic | seismology seismic tomography geoelectrics seismic velocity rate electrical conductivity earthquake volcano hydrothermal solution magmatic melt |
| url | https://www.gt-crust.ru/jour/article/view/670 |
| work_keys_str_mv | AT yufmoroz deepstructureofsouthkamchatkaaccordingtogeophysicaldata AT ligontovaya deepstructureofsouthkamchatkaaccordingtogeophysicaldata |