Note on Strain Release Variation with Depth
Item
Title (Dublin Core)
Note on Strain Release Variation with Depth
Description (Dublin Core)
In the present paper an attempt is made to approach<br />the problem of the upper mantle structure by studying the strain relea.se<br />variation with depth. If the method and data used in this paper are adequate,<br />we may be allowed to say that although there is no strain release<br />evidence for the depth of the upper boundary of the asthenospliere zone on<br />account of lack of adequate accuracy in the determination of focal depths,<br />nevertheless there is ample indication of a discontinuity at about 125 km<br />depth. The abrupt change in the rate of decrease in the strain release<br />with depth near this level clearly indicates that a sudden decrease in the<br />yield strength of the material in the earth should occur at about this depth.<br />I t might even be possible to think that the melting point of some kind of<br />crystal grains or rocks in the earth is attained at that depth. However,<br />this does not involve a completely molten state. This state should rather<br />occur at depths where there is a complete lack of strain release. Regionally<br />this state is attained at different depths, but in some regions the partially<br />molten state, i. e. the heterogeneity of the mantle, probably recurs or increases<br />due to the pressure increase or some other reason and reaches a minor<br />maximum beyond which it might be possible to speculate that the heterogeneity<br />of the mantle falls off rapidly and a continuous layer of material<br />in molten state covers the whole earth. If data from other sources will<br />confirm this structure, there will be good reasons to think of redefining<br />the upper boundaries of surface and intermediate shocks at depths of 125<br />and 425 km or thereabouts, respectively.
Creator (Dublin Core)
A. G. GALANOPOULOS
Subject (Dublin Core)
Meteorology. Climatology
QC851-999
Geophysics. Cosmic physics
QC801-809
Publisher (Dublin Core)
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Date (Dublin Core)
1964-06-01T00:00:00Z
Type (Dublin Core)
article
Identifier (Dublin Core)
10.4401/ag-5212
1593-5213
2037-416X
https://doaj.org/article/677768302bca4c8ea924b93fad0f3f1b
Source (Dublin Core)
Annals of Geophysics, Vol 17, Iss 3, Pp 337-352 (1964)
Language (Dublin Core)
EN
Relation (Dublin Core)
http://www.annalsofgeophysics.eu/index.php/annals/article/view/5212
https://doaj.org/toc/1593-5213
https://doaj.org/toc/2037-416X
Provenance (Dublin Core)
Journal Licence: CC BY