Rescaled Range Analysis of Microtremors in the Yun-Chia Area, Taiwan

• Main Authors: Young-Fo Chang, Chien-Chih Chen, Huey-Chu Huang
• Format: Article
• Language: English
• Published: Chinese Geoscience Union 2006-01-01
• Series: Terrestrial, Atmospheric and Oceanic Sciences
• Subjects: Rescaled range; Microtremor; Memory effect; Fractal dimension
• Online Access: http://tao.cgu.org.tw/images/attachments/v171p129.pdf

Hurst’s analysis of natural background microtremors at 10 stations in Yun-Li and Chia-Yi Counties, Taiwan, yields high values of H, ranging from 0.733 to 0.934. These values are found to be site-specific and stationary. Microtremors recorded in the foothills, on a hillside and at rock sites have higher H values than those on the alluvial plain, near the coast or at soil sites although they may very well be affected by the local environment and geology. Since low-frequency microtremors tend to be more persistent in time, we suggest that the high values of the Hurst exponent H may be causally correlated with the presence of low frequencies. This seems likely because Hurst exponents H > 0.5 mean a higher statistical persistence of a random signal.