Carolyn, I am forwarding the following e-mail from Alan Lavander. Will this be OK or should I try to get a hard copy from him? Peter ---------------------------------------------------------------------- From alan@geophysics.rice.edu Tue Jan 25 16:07:17 2000 X-Sender: alan@geophysics.rice.edu Date: Tue, 25 Jan 2000 16:11:08 -0600 To: glaske@ucsd.edu, gmasters@ucsd.edu, fvernon@ucsd.edu, pshearer@ucsd.edu, hilst@mit.edu, alan@geophysics.rice.edu From: Alan Levander Subject: SSA Abstract Mime-Version: 1.0 --=====================_948859868==_ Content-Type: text/plain; charset="us-ascii" Hi, Attached is an abstract for the SSA. I'm sorry I didn't get it out to you for review, I promptly caught the flu upon returning to Houston from Scripps. As you will probably note, this is past the due date for SSA abstracts, but I think that is ok. The abstract basically covers what we produced for the white paper. Any thoughts on further work to make what we have done more satisfying and possibly produce a couple GRL or similar style papers on USArray? The time is ripe to do this. Alan --=====================_948859868==_ Content-Type: text/plain; charset="us-ascii" Content-Disposition: attachment; filename="USArray.SSA.abstract.final.txt" USARRAY EARTHQUAKE RECORDING AND STRUCTURAL IMAGING LEVANDER, A., Geology and Geophysics Department, Rice University, Houston, TX 77005, alan@geophysics.rice.edu; SHEARER, P.M., LASKE, G., and VERNON, F.L., IGPP, Scripps Institution of Oceanography, La Jolla, CA 92093-0225; and VAN DER HILST, R.D., Department of Earth, Atmosphere,and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, 02139. The USArray component of Earthscope is a continental scale seismic investigation of North America with related geologic and other geophysical investigations. Here we discuss preliminary studies on the earthquake population USArray will record and aspects of its structural imaging capabilities. Data from existing broadband arrays and empirical relations provide the likely detection threshold of events for USArray (mb > 4.5-5.0) and thus the numbers, and azimuth and distance distributions of regional and teleseismic events for any transportable array footprint, as well as the entire 10 year experiment. We have estimated the likely numbers of P and S wave travel times for body wave tomography, events suitable for surface wave tomography, and events suitable for receiver functions for structural imaging. In terms of raw data, USArray will produce 5.6 Tbyte/year of continuous, near real time data, more than the GSN and PASSCAL combined. For most common analysis methods, USArray will provide several orders of magnitude more data than the community is accustomed to analyzing. Synthetic studies of migrated receiver functions show that the transportable array, with a 70km instrument interval, can image targets as shallow as 100km depth and likely as deep as the CMB in the low frequency passband. Resolution of discrete objects is ~45 km, and that of interface variations is ~15 km. Deployments of the flexible array (with instruments at 10 km) can image features in the high frequency passband at least as shallow as 25 km. Resolution of objects is about 4 km, and that of interface depths is about 2 km. Synthetic surface wave inversions recover velocity anomalies a quarter of the size of the 70km station interval with little smearing. They also show relatively little smearing for anomalies outside USArray, e.g. on the continental margins, provided ray coverage is adequate. --=====================_948859868==_ Content-Type: application/rtf; charset="us-ascii" Content-Disposition: attachment; filename="USArray.SSA.abstract.final.rtf" {\rtf1\ansi\ansicpg1252\uc1 \deff0\deflang1033\deflangfe1033{\fonttbl{\f0\froman\fcharset0\fprq2{\*\panose 02020603050405020304}Times New Roman;}{\f30\froman\fcharset238\fprq2 Times New Roman CE;}{\f31\froman\fcharset204\fprq2 Times New Roman Cyr;} {\f33\froman\fcharset161\fprq2 Times New Roman Greek;}{\f34\froman\fcharset162\fprq2 Times New Roman Tur;}{\f35\froman\fcharset177\fprq2 Times New Roman (Hebrew);}{\f36\froman\fcharset178\fprq2 Times New Roman (Arabic);} {\f37\froman\fcharset186\fprq2 Times New Roman Baltic;}}{\colortbl;\red0\green0\blue0;\red0\green0\blue255;\red0\green255\blue255;\red0\green255\blue0;\red255\green0\blue255;\red255\green0\blue0;\red255\green255\blue0;\red255\green255\blue255; \red0\green0\blue128;\red0\green128\blue128;\red0\green128\blue0;\red128\green0\blue128;\red128\green0\blue0;\red128\green128\blue0;\red128\green128\blue128;\red192\green192\blue192;}{\stylesheet{\ql \li0\ri0\widctlpar\faauto\adjustright\rin0\lin0\itap0 \fs24\lang1033\langfe1033\cgrid\langnp1033\langfenp1033 \snext0 Normal;}{\*\cs10 \additive Default Paragraph Font;}{\*\cs15 \additive \ul\cf2 \sbasedon10 Hyperlink;}}{\info{\title USArray Earthquake Recording and Structural Imaging}{\author Alan Levander} {\operator Alan Levander}{\creatim\yr2000\mo1\dy25\hr15\min46}{\revtim\yr2000\mo1\dy25\hr15\min46}{\printim\yr2000\mo1\dy25\hr12\min27}{\version2}{\edmins1}{\nofpages1}{\nofwords0}{\nofchars0}{\*\company Rice Earth Sciences}{\nofcharsws0}{\vern8247}} \widowctrl\ftnbj\aenddoc\noxlattoyen\expshrtn\noultrlspc\dntblnsbdb\nospaceforul\hyphcaps0\formshade\horzdoc\dghspace120\dgvspace120\dghorigin1701\dgvorigin1984\dghshow0\dgvshow3\jcompress\viewkind1\viewscale100\pgbrdrhead\pgbrdrfoot\nolnhtadjtbl \fet0 \sectd \linex0\endnhere\sectdefaultcl {\*\pnseclvl1\pnucrm\pnstart1\pnindent720\pnhang{\pntxta .}}{\*\pnseclvl2\pnucltr\pnstart1\pnindent720\pnhang{\pntxta .}}{\*\pnseclvl3\pndec\pnstart1\pnindent720\pnhang{\pntxta .}}{\*\pnseclvl4 \pnlcltr\pnstart1\pnindent720\pnhang{\pntxta )}}{\*\pnseclvl5\pndec\pnstart1\pnindent720\pnhang{\pntxtb (}{\pntxta )}}{\*\pnseclvl6\pnlcltr\pnstart1\pnindent720\pnhang{\pntxtb (}{\pntxta )}}{\*\pnseclvl7\pnlcrm\pnstart1\pnindent720\pnhang{\pntxtb (} {\pntxta )}}{\*\pnseclvl8\pnlcltr\pnstart1\pnindent720\pnhang{\pntxtb (}{\pntxta )}}{\*\pnseclvl9\pnlcrm\pnstart1\pnindent720\pnhang{\pntxtb (}{\pntxta )}}\pard\plain \ql \li0\ri0\widctlpar\faauto\adjustright\rin0\lin0\itap0 \fs24\lang1033\langfe1033\cgrid\langnp1033\langfenp1033 {USARRAY EARTHQUAKE RECORDING AND STRUCTURAL IMAGING \par \par LEVANDER, A., Geology and Geophysics Department, Rice University, Houston, TX 77005, }{\field{\*\fldinst { HYPERLINK "mailto:alan@geophysics.rice.edu" }{{\*\datafield 00d0c9ea79f9bace118c8200aa004ba90b02000000170000001900000061006c0061006e004000670065006f0070006800790073006900630073002e0072006900630065002e006500640075000000e0c9ea79f9bace118c8200aa004ba90b400000006d00610069006c0074006f003a0061006c0061006e00400067006500 6f0070006800790073006900630073002e0072006900630065002e0065006400750000000000525241}}}{\fldrslt {\cs15\ul\cf2 alan@geophysics.rice.edu}}}{ ; SHEARER, P.M., LASKE, G., and VERNON, F.L., IGPP, Scripps Institution of Oceanography, La Jolla, CA 92093-0225; and VAN DER HILST, R.D., Department of Earth, Atmosphere,and Planetar y Sciences, Massachusetts Institute of Technology, Cambridge, MA, 02139. \par \par The USArray component of Earthscope is a continental scale seismic investigation of North America with related geologic and other geophysical investigations. Here we discuss prelimin ary studies on the earthquake population USArray will record and aspects of its structural imaging capabilities. \par \par Data from existing broadband arrays and empirical relations provide the likely detection threshold of events for USArray (m}{\sub b}{ > 4.5-5.0) and thus the numbers, and azimuth and distance distributions of regional and teleseismic events for any transportable array footprint, as well as the entire 10 year experiment. We have estimated the likely numbers of P and S wave travel times for body wave to m ography, events suitable for surface wave tomography, and events suitable for receiver functions for structural imaging. In terms of raw data, USArray will produce 5.6 Tbyte/year of continuous, near real time data, more than the GSN and PASSCAL combined. For most common analysis methods, USArray will provide several orders of magnitude more data than the community is accustomed to analyzing. \par \par Synthetic studies of migrated receiver functions show that the transportable array, with a 70km instrument interval , can image targets as shallow as 100km depth and likely as deep as the CMB in the low frequency passband. Resolution of discrete objects is ~45 km, and that of interface variations is ~15 km. Deployments of the flexible array (with instruments at 10 km) can image features in the high frequency passband at least as shallow as 25 km. Resolution of objects is about 4 km, and that of interface depths is about 2 km. \par \par Synthetic surface wave inversions recover velocity anomalies a quarter of the size of the 70k m station interval with little smearing. They also show relatively little smearing for anomalies outside USArray, e.g. on the continental margins, provided ray coverage is adequate. \par \par }} --=====================_948859868==_ Content-Type: text/plain; charset="us-ascii" XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX Alan Levander Geology & Geophysics Department Rice University 6100 Main Street Houston, Texas 77005 713-348-6064 713-348-5214 Fax http://terra.rice.edu XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX --=====================_948859868==_--