New Zealand Journal of Geology and Geophysics abstracts
Geographical distributions of prospective foreshock probabilities in
New Zealand
Alistair Merrifield
School of Mathematics and Computing Sciences
Victoria University of Wellington
P.O. Box 600
Wellington, New Zealand*
Martha K. Savage
Institute of Geophysics
Victoria University of Wellington
David Vere-Jones
School of Mathematics and Computing Sciences
Victoria University of Wellington
*Present address: School of Mathematics and Statistics F07, University
of Sydney,
NSW 2006, Australia. Email: alistair@maths.usyd.edu.au
Abstract The prospective foreshock occurrence rate is
calculated as the sample conditional probability of a larger earthquake following
a potential foreshock of certain magnitude. A non-aftershock event is considered
a foreshock if it is followed by a larger magnitude event within the next
5 days and within a radius of 30 km from the epicentre of the original
earthquake. An evaluation of foreshock probabilities is carried out on a
regional basis over New Zealand, and the probabilities are presented in the
form of an overlay map. The Taupo Volcanic Zone features as an area of larger
probability in these maps. As the magnitude difference between the foreshock
and mainshock increases, the foreshock probability in this area decreases.
This is attributed to swarm-like events in the area. Foreshock probability
maps are shown for a variety of foreshock magnitude bins.
Keywords foreshocks; seismicity; foreshock probabilities;
New Zealand; Taupo Volcanic Zone
G02039; Received 7 August 2002; accepted
3 December 2003; online publication date 20 May 2004
New Zealand Journal of Geology & Geophysics, 2004, Vol. 47: 327–339
0028–8306/04/4702–0327 © The Royal Society of New Zealand 2004
PDF file of entire paper: Print-quality (1455K)
| screen-quality (676K)
This year's abstracts |
Journal home page |
All abstracts |
Publishing home page
