-logy ancient greek catastrophe modeling cryoseism cryosphere dinosaur earth earthquake earthquake engineering earthquake prediction engineering geology explosion gns science geology geophysics harold jeffreys helioseismology impact crater joule land mine liquid longitudinal wave love wave mantle plume nuclear testing outer core paleoseismology petroleum plate tectonics propagation rayleigh wave reflection seismology richard dixon oldham salt dome seismic loading seismic performance analysis seismic source seismic tomography seismic wave seismogram seismometer shear transverse wave van method volcanology wave zhang heng