SCEC - EarthScope (PBO) a confluence of interests Ken Hudnut U. S. Geological Survey, Pasadena

How can EarthScope (& ANSS) help to further SCEC science goals? Review what we have (SCEC CMM3 & SCIGN) Examine the EarthScope & SCEC proposals PBO 2 workshop mini-proposal process defined configuration - backbone & clusters PBO committees to select sites - to go from general to specific & meet science goals What if something else would be ‘better’? Any suggested changes should go to PBO SC Identify opportunities for synergy Missions & funding levels of agencies and NGO’s Joint development of data products

1 st Year Combined time series ( ) 3 rd Year Real-time earth- quake response 5 th Year Resolve rates on primary LA basin faults (and others) SCIGN Data Products * *NASA grant - Webb, PI

1 st Year Complete and distribute CMM3 3 rd Year Integrate InSAR with GPS for vertical defor- mation rates 5 th Year Resolve rate dis- crepancies between geology and geodesy SCEC Tectonic Geodesy

Understanding transient deformation Temporal & spatial variations do occur: Temporal & spatial variations do occur: Clustering (e.g., Basin & Range, ECSZ, Asia) Clustering (e.g., Basin & Range, ECSZ, Asia) Discrepant geological and geodetic rates Discrepant geological and geodetic rates Sequences involving fault interaction (e.g., Joshua Tree - Landers - Big Bear - Hector Mine; Anatolian system, etc.) Sequences involving fault interaction (e.g., Joshua Tree - Landers - Big Bear - Hector Mine; Anatolian system, etc.) PBO and SCEC have nearly identical stated scientific goals on this range of related topics PBO and SCEC have nearly identical stated scientific goals on this range of related topics Courtesy Anke Friedrich

Understanding fault interaction Emerging view of large events as a composite of sub-events or asperitiesEmerging view of large events as a composite of sub-events or asperities Dynamic triggeringDynamic triggering Static triggeringStatic triggering Important to study analogous eventsImportant to study analogous events Cascading rupture - is there order in the chaos?Cascading rupture - is there order in the chaos? San Andreas fault - continental transform with excellent on-land exposure of ‘creeping to locked’ transition zones, long simple sections, and ample fault zone complexitySan Andreas fault - continental transform with excellent on-land exposure of ‘creeping to locked’ transition zones, long simple sections, and ample fault zone complexity Bayarsayhan et al., 1996 Kurushin et al., San Andreas 1957 Gobi-Altay

San Andreas fault 35 mm/yr slip rate;35 mm/yr slip rate; >70% of plate motion>70% of plate motion 1685, 1812, 1857 eq’s1685, 1812, 1857 eq’s Big Bend compressionBig Bend compression 1971 Sylmar (M 6.7)1971 Sylmar (M 6.7) 1994 Northridge (M 6.7)1994 Northridge (M 6.7) SoCal is now heavily ‘wired’ - need more?SoCal is now heavily ‘wired’ - need more? 150+ BB CISN stations150+ BB CISN stations 250+ SCIGN stations250+ SCIGN stations Catalog; SCEC CMM3Catalog; SCEC CMM3 ‘Natural laboratory’‘Natural laboratory’ Likely source of most future ‘Big Ones’Likely source of most future ‘Big Ones’

What is EarthScope? USArray 400 station transportable array “big foot” ~2400 instrument flexible array PBO 875 permanent GPS stations 175 borehole strainmeters/seismometers 100 campaign (portable) GPS systems 5 laser strainmeters Data and data products SAFOD 4-km-deep scientific drilling project into the San Andreas fault zone near Parkfield Fully open data policy

What is PBO? Five year build out phase Five year O&M phase Total 10-year operational commitment Six regional offices in Alaska, Pacific NW, Basin & Range, Rocky Mtns, Southern and Northern California Each region has dedicated resources for recon, permitting, installation, maintenance, and data Nominal data set – 30 sec data file downloaded daily Potential data sets 1 sec real time 5 Hz on-demand Two precise processing centers Two archive/distribution centers

125 SCIGN stations proposed for support under NSF existing networks proposal (PBO relies on continued existence of SCIGN & diverse matching funds) NSF funded ‘existing arrays’ proposal fully for next 1.5 years - plan & carry out a transition to PBO operations and maintenance by the end of 5 yrs. ~170 new continuous GPS stations; SAF, ECSZ, transition zones (along-strike and with depth) ~64 borehole strainmeters (yellow); 5 long-base laser strainmeters (Salton Trough ECSZ & PKF vicinities) PBO and SCIGN

For discussion CISN, ANSS, EarthScope, and PBO do not optimally address questions in earthquake source physics (e.g., SCEC FARM workshop topic on co- seismic phenomena); how can plans be modified to help rectify this? Are we too late? How can we measure D c ? Stress heterogeneity? Heaton slip pulses? Need 3D particle motions close to fault (e.g., the San Andreas fault in the Carrizo Plain and Coachella Valley in SoCal - large events ~likely) Need high resolution deformation field for co- seismics to map slip distributions - without InSAR EarthScope is deficient; what else can be done? (Geo-EarthScope to provide high-res imagery) Fall AGU 2003 & SSA 2004 (Palm Springs)