Hi Keith,
My name is Alby I run a station just to the east of Perth, Western =
Australia.
Just east of my station is an area called the South West Seismic Zone =
which is the most active earthquake zone in Australia.
I often note what I call triggers, one event seeming to trigger another =
as you mention regarding the California M7 event.
I recorded a M4 event 40 minutes after the Boxing Day earthquake, this =
M4 event was in the SWSZ in a new area that became active in November =
last year.
On Sunday night I recorded a M4.3 event at a place called Cadoux =
followed 8 hours later by a M4.5 event 30km away at a siding called =
Burakin.
This occurs frequently.
As to the mechanism, who knows?
Rapid stress transfer, harmonic activation of a nearby fault primed to =
go?
Anyway I thought your observation interesting as it struck a chord with =
my observations here.
By the way for further info on this check out the Landers event of 1992 =
in Southern California.
Cheers,
Alby.







Hi Keith,
My name is Alby I run a station just to =
the east of=20
Perth, Western Australia.
Just east of my station is an area =
called the South=20
West Seismic Zone which is the most active earthquake zone in=20
Australia.
I often note what I call triggers, one =
event=20
seeming to trigger another as you mention regarding the California M7=20
event.
I recorded a M4 event 40 minutes after =
the Boxing=20
Day earthquake, this M4 event was in the SWSZ in a new area that became =
active=20
in November last year.
On Sunday night I recorded a M4.3 event =
at a place=20
called Cadoux followed 8 hours later by a M4.5 event 30km away at a =
siding=20
called Burakin.
This occurs frequently.
As to the mechanism, who =
knows?
Rapid stress transfer, harmonic =
activation of a=20
nearby fault primed to go?
Anyway I thought your observation =
interesting as it=20
struck a chord with my observations here.
By the way for further info on this =
check out the=20
Landers event of 1992 in Southern California.
Cheers,
Alby.
Martin =
Observatory