Research on spectral ratio of horizontal to vertical component for elastic model and surface microtremors

The rationality for spectral ratio method of horizontal to vert ical component （ H/V method） for microtremors is discussed with a model of an elastic laye r over a half-space.The H/V expressions of surface microtremors for l ayered media are derived.The feasibility of estimating the horizontal transfer f unction from H/V of surface microtremors is discussed.It is shown that the spectral ratio method of horizontal to vertical component can be used to estimat e the site predominant frequency for surface microtremors when the impedance rat io is larger than 3.The relationship between s ite frequency and surface microtremors is f_S=0.8f_R+0.06 .Howe ver the amplification factor of site is difficult to be decided by H/V meth od.