Earthquake precursors for Kamchatka as seen from ionosphere behavior and Sq-variation
Abstract
By the analysis of pattern dynamics of F2 ionosphere region and variability of Sq -magnetic field variations which appear in seismoactive Far East locale during opening-up and implementation of earthquakes, it is shown that tectonic processes in the Kurilo-Kamchatka zone result in generation of regional or local magnetosphere-ionosphere disturbances or MID-L (index L indicates on litosphere genesis of disturbances). The indicated disturbances are non-cohesive directly neither with solar nor with auroral activity. During these disturbances in an ionosphere are watched composite and magneto-conjugated changes of F2 structure in the nothern and southern hemisperes. The Fourier analysis of concrete behaviour of Sq-variations that appeare a few days prior to earthquake demonstrates that a disturbance such as MID-L in a magnetic field are pronounced as slow variations of 2-5 day duration. It is modified, basically, the value of constant component of Sq-variations and is exhibited in sluggish changes.The presence such magnetic disturbances of tectonic genesis can be a consequent of change of electrical properties of earth crust or electric current conductivity in locale of the Kurilo - Kamchatka trough, and also changes of distribution of marine currents in this locale. The amplitude and registered duration of MID-L is directly proportional of earthquake energy and a capability of their clear allocation exists for magnitudes M> 3.0. The indicated properties magnetic components of MID-L allow to suspect the presence of its secular variation with period, commensurable with seismic cycle.
- Publication:
-
EGS - AGU - EUG Joint Assembly
- Pub Date:
- April 2003
- Bibcode:
- 2003EAEJA.....3077S