1. Division of Physics, Math, and Astronomy California Institute of Technology Pasadena CA USA
2. Gran Sasso Science Institute (GSSI)
3. Laboratori Nazionali del Gran Sasso INFN Assergi Italy
4. Seismological Laboratory California Institute of Technology Pasadena CA USA
5. Institute of Geophysics ETH Zurich Zürich Switzerland
6. School of Physics and Astronomy University of Minnesota Minneapolis MN USA
7. Ozgrav, School of Physics University of Melbourne Parkville Victoria Australia
8. Department of Geological Sciences Indiana University Bloomington IN USA