Forwarded by RM on behalf of Russ Evans:
Are you sure you mean P-waves? On average, P-waves carry only a small
fraction (~8%) of the seismically released energy; because they are
primarily vertical accelerations, amplitude-for-amplitude (or
energy-for-energy) they ought to be (and probably are) less damaging than
other wave types; and because they arrive first, the effects of P-induced
shaking are likely to be overwhelmed by those of later phases, arriving (at
100km) ten seconds or so later.
Russ Evans
-----Original Message-----
From: Umberto Fracassi [mailto:[log in to unmask]]
Sent: 19 November 2003 15:22
To: [log in to unmask]
Subject: felt reports distribution
Hi all and apologies for x-posting.
A quick but provocative query:
is there any documented study of the transmissivity, even far (80/100+
km) from the seismogenic source, of P-waves and damage on competent,
consistently thick (6/7 km, from subsurface data) carbonate platforms?
In other words, how much can felt reports from a major seismic event
cluster on terrains pertaining to an outcropping major foreland?
Many thanks for any hint and have a pleasant day,
Ciao,
Umberto
--
Umberto Fracassi
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