Catholic University of America, Department of Physics, Washington, DC 20064 United States ; Academy of Sciences, Institute of Geology, Prague, 16502 Czech Republic
NASA, Goddard Space FLight Center, Code 691, Greenbelt, MD 20771 United States ;
University of Helsinki, Division of Geophysics, Department of Physical Sciences, Helsinky, 00014 Finland ; Charles University, Department of Applied Geophysics, Faculty of Natural Sciences, Prague, 12843 Czech Republic ;
University of Hawaii at Manoa, SOEST-HIGP, 1680 East West Road, Honolulu, HI 96822 United States ;
University of Hawaii at Manoa, SOEST-HIGP, 1680 East West Road, Honolulu, HI 96822 United States ;