Geophysical data on deep-seated magmatic activity below Kamchatka and an estimate of the forces that cause the rise of magmas into volcanoes
Titel:
Geophysical data on deep-seated magmatic activity below Kamchatka and an estimate of the forces that cause the rise of magmas into volcanoes
Auteur:
Fedotov, S. A.
Verschenen in:
International geology review
Paginering:
Jaargang 19 (1977) nr. 6 pagina's 661-670
Jaar:
1977-06
Inhoud:
Using geophysical data, we studied the mechanism of deep-seated magmatic and volcanic activity in the region of the island arcs and associated structures. Data on magmatic activity below the volcanic belt of East Kamchatka, obtained during geophysical investigations, mainly during detailed seismological investigations and deep seismic sounding, provide evidence for an association between the volcanoes and the processes in the Pacific Ocean focal layer of earthquakes, and for the accumulation of magmas below the volcanic belt at depths less than 60 km. We found anomalous columnar bodies more than 5 to 7 km across, linking the volcanoes with the focal layer, and a very large concentration of convective heat flow and volatiles in the magma columns feeding the volcanoes. As to the role of different forces in the uprise of magmas into the volcanoes, hydrostatic forces probably predominate in the asthenosphere, supplemented by tectonic pressure in the lithosphere and forces associated with boiling of magmas during release of volatiles in the crust, especially in its upper layers.—Author.
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