Application of the VLF-EM method with EEMD to the study of a mud volcano in southern Taiwan

A nonlinear method of removing harmonic noise in geophysical data

“…In this study, we generally call this new and evolving technique "the EEMD method" which includes the original EMD algorithm and the Hilbert-Huang Transform (HHT). The application of this analysis has been widely demonstrated in the recent peer-reviewed literature both in science and engineering communities, and it has been verified very effective in spectrum analysis and noise filtering (Gloerson and Huang, 2003;Flandrin et al, 2004;Peel and McMahon, 2006;Battista et al, 2007;Jeng et al, 2007;Huang and Wu, 2008;Feldman, 2009;Tsolis and Xenos, 2009;Jackson and Mound, 2010;Lee and Ouarda, 2010;Lin and Jeng, 2010). Some contributions of the EMD technique have been made on the seismic data processing; however, due to the high attenuation nature of the reflection data, it still has room for more elaborate studies.…”

“…Huang (2005, 2009) suggested that 0.2 and a value of few hundreds for the two parameters would lead to a good result in most cases. Lin and Jeng (2010) allowed 0.5 and 100 for R and k, respectively, to process their relatively small quantity of data dominated by low frequency signals. In our case, the data quantities are large and most of the data contain high frequency signals; therefore, we use 0.1 for the added noise amplitude R, and use 50 for the number of k in EEMD algorithm to compromise with the computer time.…”

“…The processing scheme was implemented by employing the logarithmic transform to the data at first (Fig. 2c), and then by applying the EEMD method to establish a dyadic filter bank (Wu and Huang, 2009;Lin and Jeng, 2010) which contains the decomposed components (IMFs and a residue) of physical significance. Figure 3 shows the dyadic filter bank of nine IMFs derived from the harmonic noise affected synthetic model before logarithmic transform, in which IMF- 9 is the residue representing the trend or the background energy of the data analyzed.…”

Mud volcanoes in central Italy: Subsoil characterization through a multidisciplinary approach

“…Geoelectric assessments (e.g., 3D ERT) of MVs in New Zealand are discussed in Zeyen et al (2011), while electromagnetic applications (VLF-EM) undertaken in Taiwan have been discussed by Lin and Jeng (2010). In particular, Zeyen et al (2011) obtained a 3D resistivity imaging for the uppermost 25-30 m of depth from the inversion of densely spaced profiles.…”

Landform characterization using geophysics—Recent advances, applications, and emerging tools

“…Beylich et al (2004) used RMT in combination with water discharge and water chemistry data to characterize regolith thickness in a study of chemical denudation in an arctic-alpine drainage basin. VLF was used to characterize the internal structure of a mud volcano (Lin and Jeng, 2010) and for the study of faults (Gürer et al, 2009). …”