[1] Univ Nacl Autonoma Mexico, Posgrad Ciencias Tierra, Mexico City, Mexico
[2] Univ Southern Calif Los Angeles, Los Angeles, CA USA
[3] Univ Nacl Autonoma Mexico, Dept Sismol, Inst Geofis, Mexico City, Mexico
[4] Natl Inst Earth Phys, Magurele, Ilfov, Romania
[5] Comprehens Nucl Test Ban Treaty Org, Vienna, Austria
[6] Univ Michoacana, Inst Invest Ciencias Tierra, Morelia, Michoacan, Mexico