As chairman of the US Council of the National Seismic System
(CNSS) I have been trying to improve the cooperation and collaboration
between the traditional seismic network and the strong-motion networks in
the US.  Many US seismic networks are now operating strong-motion
instruments as part of their network operation.  A problem is that there
is no naming convention for strong-motion data in SEED. Currently two
different codes might be applicable but neither is truely appropriate. 
The instrument code `L' for low gain seismometer is being used by some
networks for strong-motion accelerometers; however, some networks
(sometimes the same one) also use this code for low-gain velocity sensor. 
These are two VERY different instruments, with different characteristics
and, most importantly, different saturation levels.  The most important
aspect of a strong-motion instrument is that it will not clip or saturate
even under very strong shaking (~1G+).  This is almost never the case for
low-gain seismometers.  Another existing code which might be used is 'G'
for Gravimeter/Accelerometer Seismometer.  As far as I know this code is
not often used but was reserved for recording gravimeters (like the
original IDA instruments); ie very sensitive accelerometers which would
certainly saturate under strong shaking and thus of no use to the
strong-motion community.

The strong-motion/engineering community is trying to standardize on a
distribution data format.  While I don't think that they will necessarily
adopt SEED (though that is a possibility) they certainly would not without
having an instrument code which is appropriate for their use. 

I would suggest that an unused letter (not many left) be picked for this
purpose and be defined with something like:

	#	Strong-motion accelerometer  (>= 1G on-scale)

This code should only be used for sensors with flat response to
acceleration and with an on-scale output of at least 1G and can have the
traditional orientation codes.

	Thanks you for your consideration and I look forward to seeing you
again in early December.


	Steve Malone			E-mail: steve@geophys.washington.edu
	Geophysics Program 		Phone: (206) 685-3811
	University of Washington	FAX: (206)543-0489
	Box 351650			Office: ATG-226
	Seattle, WA 98195	http://www.geophys.washington.edu