I've actually never asked this question of a sesmologist. I've also never seen a 'code of ethics' of a seismologist.

About the closest I've seen cal tech come to posting an alert was after Hector - they posted as strong an alert message that the Governor's staff would allow on the EDIS message area - they were 'concerned' (but concern was too strong a word for the alert message) about the southern san andreas due to motion from/during the Hector quake - they are not particularly concerned now - it was more of a worry of a quake being triggered by Hector.

If they really think something is up - they will get that sort of message out. We need to read between the lines. Its not the seismologists themselves - their hands are tied by their employers.

Canie