Descr: We are currently (Summer 04) installing three long(800 meter)baseline tiltmeters in five locations along with continuous GPS to measure static, near-field deformation associated with periodic Cascadia slow earthquakes, also called ETS events. Two tiltmeters are going in this week (Jul 19) and we have five 8' deep vaults with concrete floors on which we'd like to place seismomters. The tremor which accompanies slow earthquakes has peak frequencies in the 1-5 hz range, so in theory a standard, L4 non-broadband instrument should suffice. But we'd also like to see if there are long period tilts that can be recovered as well, so ideally we'd like to request a mixture of L4 and BB instruments like a Guralp or STS-2. We are not currently funded to conduct a PASSCAL experiment, and our understanding is that instruments for the three arrays that have been funded to study Cascadia slow earthquakes (Steve Malone, UW Seattle) are all in full use. So we're interested in whatever instruments, say 6 or 8, could be spared without being unfair to funded Passcal PI's waiting patiently for their instruments. I do have funding for the Tiltmeters from NSF Geophysics, and can therefore leverage many of the costs associated with deploying the seismic instruments through the tiltmeter grant. We have concrete vaults to place the instruments in already built. One other thing: These tiltmeters are being co-located with PBO GPS stations and, given bedrock constraints, PBO strainmeters. Adding seismometers, particulary USArray instruments, to the tiltmeter-GPS- strainmeter package in a region where known transients are occurring predictably and have both seismic and geodetic signals resolveable makes a whole lot of sense, since the seismomters will bridge the gap between GPS, tiltmeters and strainmeters
