[iris-bulk] Deadline near for submissions on non-double-couple earthquakes

[Bruce R Julian]

(Please accept our apologies for multiple postings of this email)

Dear colleagues,

There are only a few days left to the deadline for abstracts to European
Seismological Commission ESC2008, 31st General Assembly,"Creta Maris",
Hersonissos, Crete, Greece, 7-2 September, 2008. Abstracts should be  
sent
till 15 June 2008.

We would welcome your contributions (oral and poster) in the thematic  
area:

3. Physics of the Earthquake Source

Session Code:  PHYS-2 - SOURCE
Session Title:
Natural and induced earthquakes: Double Couple and non-Double Couple
source mechanisms

Please visit the website at: http://www.esc2008.org/sprogramme.aspx

With best wishes,
Jan Sileny, Bruce R. Julian
Session Conveners

Jan Sileny
Geophysical Institute, Academy of Sciences
Bocni II/1401, 14131 Praha 4, Czech Republic
Tel: +420-267103016
Fax: +420-272761549
E-mail: jsi at ig.cas.cz

Bruce R. Julian
Earthquake Hazards Team        E-mail: julian at usgs.gov
U. S. Geological Survey        Office: 650/329-4797
345 Middlefield Rd., MS977     FAX:    650/329-5163
Menlo Park, CA 94025

Session Description:

The traditional view that earthquakes are caused by shear faulting has
broadened in recent decades, as data from dense networks and  
sophisticated
(e.g. broad-band) seismometers have identified departures from the
double couple (DC) source model, particularly in
environments such as volcanoes and exploited geothermal and hydrocarbon
reservoirs.

Understanding the physical source processes of these events is important
both as fundamental science and for application to volcano monitoring  
and
energy extraction.

At the same time, however, more complicated non-DC source models are  
more
difficult to quantify experimentally, and their study raises challenging
problems of the uniqueness of derived mechanisms, the resolving power of
various methods and data types, the effects of noise, and biases that  
may
result from effects such as anisotropy and inevitable deficiencies in
models of Earth structure.

These problems can introduce spurious non-DC components into calculated
source mechanisms, so realistic error budgets must be taken into account
to avoid erroneous interpretation of experimental results.

If this is done, adoption of the moment-tensor formulation allows non-DC
components to be derived reliably and offers the chance to study  
important
structural features and source processes involving fluids that are  
ignored
in pure shear-slip source models.