Abstract
As a simple, quick and inexpensive method for site characterization and deep geological survey, array microtremor survey as well as H/V observation are expected to play important roles in China's earthquake disaster prevention program, especially in the vast, economically delayed inland area. We started a co-study program on the characteristics and applications of long period microtremor in China continent since 2008. We have made microtremor observations from the coast cities like Shanghai and Tianjin through Beijing, Xi'an, to the far inland cities Lanzhou and Tianshui over the continent using long period seismometers. We also carried out some field tests of applications for structure survey. The observation shows that the level of power spectrum of long period microtremor in the coast area is the same as in Japan. From the coast to the inland area, the level reduced rapidly, but even in Tianshui, which is over 1500 kilometers from the coast, it is still possible to use for geological survey with careful observation.