1. Department of Geophysics, Colorado School of Mines , 1500 Illinois Street, Golden, CO 80401 , USA
2. Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology , 77 Massachusetts Avenue, 54-918, Cambridge, MA 02139 , USA
3. Lawrence Berkeley National Laboratory , 1 Cyclotron Road, 74R316C Berkeley, CA 94720 , USA
4. Department of Earth and Environmental Sciences, Lamont-Doherty Earth Observatory of Columbia University , 61 Route 9 W, Palisades, NY 10964 , USA
5. School of Geosciences, University of Oklahoma , 100 East boyd Street, RM 710, Norman, OK 73019 , USA