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Disturbed February.. / February 14, 2011 /

A series of strong earthquakes occurred in the first half of February: 02/07/2011 — M6,2 — Solomon Islands; 02/10/2011 — M6,5 / 6,7 — Celebes Sea, 02/11/2011 — M6,8 — Chile (and subsequent aftershocks with magnitudes greater than 6); 02/12/2011 — M5,6 — Molucca Sea, 02/12/2011 — M6,1 — Island of Tonga; 02/14/2011 — M6,6 — Chile.

Let us dwell on events in the Celebes Sea. As one of the potential earthquake-prone areas on January 21 it was marked out a zone with coordinates of ± 10 degrees in latitude and 120-130 degrees longitude. Defining signs of the preparation of a powerful earthquake (EQ) were cloudy seismotectonic indicators (CSI) at the north of the Sunda plate (Annex 1). They allowed to find out the most stressed parts of the plates, which include the mentioned above area. A series of small EQs along the plate boundary confirmed our assumptions. Also noteworthy is the EQ in the South China Sea of 01/26/2011 with M4-8, and at the Philippines (island of Luzon) of 02/08/2011 with M4-8. Utilizing CSI (A) it was calculated potential magnitude of M = ln1100 ~ 7,0. And on seismomagnetic start-up meridians after the geomagnetic disturbances 21/01/2011 it was calculated the potential date of Feb. 4 or Feb 11 ± 2 days. Geophysical indicators (Annex 2) also pointed to the possibility of more powerful EQs.

And they occurred, including the ones in the Celebes Sea: -2 events with time-interval of 2 minutes and magnitudes of 6.7 and 6.5. The total seismic energy of these EQs was equivalent to the energy of EQ with M7-0. This was signaled by the CSI (A). Thus, the forecast was justified in all three aspects — the date, location and magnitude.

It is worth to note that EQ in Celebes Sea occurred on 6-year-harmonic of the Chandler wobble. On February 5, 2005 an event with M 7.0 has also occurred. This fact is an independent prognostic sign.

Annex 1 (pdf, 684.4 Kb)

Annex 2 (pdf, 568.9 Kb)

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