1. Institute for Geophysics, Jackson School of Geosciences; University of Texas at Austin; J. J. Pickle Research Campus, Building 196, 10100 Burnet Road (R2200),; Austin; Texas; 78758; USA
2. School of Earth Sciences; Ohio State University; 125 South Oval Mall,; Columbus; Ohio; 43210; USA
3. Center for Earthquake Research and Information; University of Memphis; 3890 Central Avenue, Suite 1,; Memphis; Tennessee; 38152; USA
4. Hawaii Institute for Geophysics and Planetology; University of Hawai'i; 1680 East-West Road, POST Suite #602,; Honolulu; Hawaii; 96822; USA
5. UNAVCO Inc.; 6350 Nautilus Drive,; Boulder; Colorado; 80301; USA