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Subject: Precursor to Ms5.4 D'Entrecasteaux island quake
From: Arie Verveer ajbv@............
Date: Tue, 15 Aug 2000 14:26:38 +0800

Recently I have been experimenting with a simple system to detect
the ELF/ULF magnetic radiation band. It was used to confirm readings
from a fluxgate magnetometer. Anyhow, the data produced tantalizing 
results that may be precursors to distant quakes. It seemed to produce
readings for big quakes at depths greater than 33 km. As always the
S/N ratio wasn't very good. A new coil was constructed with 100,000 
turns and a design, so as to modify the core material. It should be 
point out that Mr Charlie Plyler has been working on the ELF quake
precursor detection. His site is at

In Larry's PSN event folder are two file 000814a.au3, 000814a.au4. These
files are 8 hours long from 16:00 hours UTC on the 14/8/00. Note the 
Ms 5.4 D'Entrecasteaux island quake at 14/8/00 at 22:11:18.1 
( 9.4S 154.2E 33km) in the file 000814a.au3. The file 000814a.au4 is
the ULF magnetic background that appears to show a quake precursor
78 minutes before the event. Also a there is a strong change in the field 
shortly before the quake. The ELF/ULF data was 0.05Hz low pass filtered.

Since the new coil has been working for only a day or so, there are no
real statistics to prove or disprove the possibility that big distant 
quakes can be detected with this coil. Charlie Plyler's system has been 
running for a while and shows some amazing results. I will continue the



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Larry Cochrane <cochrane@..............>