Western India Quake

From the USGS National Earthquake Information Center:

On January 26 2001, a major earthquake occurred IN GUJARAT, INDIA about 65 miles (110 km) north-northeast of Jamnagar, India or about 180 miles (290 km) southeast of Hyderabad, Pakistan at 8:16 PM MST today, Jan 25, 2001 (Jan 26 at 8:46 AM local time in India). A PRELIMINARY MAGNITUDE OF 7.9 WAS COMPUTED FOR THIS EARTHQUAKE. The magnitude and location may change slightly as additional data are received from other seismograph stations. According to preliminary reports, some buildings collapsed in the state of Gujarat. The earthquake was felt at Mumbai (Bombay) and Delhi, as well as Karachi and Peshawar, Pakistan and in parts of Nepal. On June 16, 1819 an earthquake in this same general area killed 1500-2000 people.

This quake was similar in magnitude to the Turkish quake in August 1999, and the prediction in this case was based on the striking outcome for the earlier quake. The period beginning 15 minutes before the actual event, continuing to 15 minutes after was taken as the formal data segment. In this case, the sharp upswing prior to the main shock was not found, and the Chisquare for the half-hour period was 1746 on 1800 degrees of freedom for a p = 0.815. See below for pseudorandom control for the formal event.

Western India Quake,
Half-Hour surrounding

There are two active eggs in India, and their data do show a sharp upswing starting about four minutes before the quake. This four-minute period has a Chisquare of 302.7 on 240 df for a probability of p = 0.004.

Western Indis Quake,
Two Indian Eggs Only

Finally, the four-hour aftermath of the West India quake shows a very strong deviation in the data from all eggs in the GCP network. It is sufficiently consistent that the trend reaches a significance level or odds ratio of 3 in 100. The Chisquare is 14718 on 14400 degrees of freedom, corresponding to a p = 0.031.

Western Indis Quake,
four hour aftermath

A control comparison, using corresponding data from a pseudorandom source, has Chisquare 1951.7 on 1800 df and p = 0.007. In contrast to the real data, which showed no effect, we have in this case a striking result for the control data. The following graph displays the cumulative deviation of the pseudorandom data. Western India Quake, Pseudo


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