1. Roy M. Huffington Department of Earth Sciences Southern Methodist University Dallas CA USA
2. Berkeley Seismological Laboratory University of California Berkeley CA USA
3. Department of Earth and Planetary Science University of California Berkeley CA USA
4. Jet Propulsion Laboratory California Institute of Technology Pasadena CA USA
5. Earth Observatory of Singapore Nanyang Technological University Singapore
6. Now at School of Earth and Space Sciences, Peking University Beijing China