The Microtremor Survey Method

摘要: Among geophysical methods, there are many techniques which use the “natural field,” signal,” or phenomena.” For example, they include gravity survey method, magnetic spontaneous potential (SP) measurement in electrical magnetotelluric method electromagnetic and radiometric measurements (Dobrin Savit, 1988; SEGJ, 1989). These known as field methods.” methods have been initiated, researched, developed means of understanding geological structure by respective physical property. They presently used their own right to augment other but typically utilized a reconnaissance prior committing detailed such reflection refraction seismic surveys. The ubiquitous, weak, low amplitude vibrations may be recorded on surface Earth commonly called microtremors. form one category signals” Until recently, has not an established positively harness this natural phenomenon for estimation subsurface structure. Several research projects during mid-twentieth century documented kinds waves that constitute microtremors relationship between structure. them Aki 1957) Toksoz 1964 suggested application structure. Research progressed through 1970s concentrating detection earthquake records contaminated noise, pulsation (e.g., Capon, 1969). The success was facilitated concurrent development digital recording systems enabled data multiple array observation networks processing analysing data. results researchwere applied traveling among vibration. In fact, were estimate Lacoss et al., 1969; Liaw McEvilly, 1979; Asten Henstridge, 1984; Horike, 1985; Matsushima Okada, 1990a). The new exploration designated microtremor (MSM) Okada al. (1990), imaging structure, using advanced over last ten years. This if effectively, can furnish preliminary appraisal before Alternatively, extending scarce from point profile data, plane data." As MSM utilizes signal found abundance anywhere Earth, is simple operation does require intensive environmental safety precautions.