Generalized orthonormal moment tensor decomposition and its source-type diagram

• Published in: Journal of seismology Vol. 25; no. 1; pp. 55 - 71
• Main Authors: Huang, Ting-Chung, Wu, Yih-Min
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01.02.2021; Springer Nature B.V
• Subjects: Decomposition; Dipoles; Earth and Environmental Science; Earth Sciences; Geophysics/Geodesy; Geotechnical Engineering & Applied Earth Sciences; Hydrogeology; Mathematical analysis; Methods; Original Article; Seismology; Structural Geology; Tensors; Compensated linear vector dipole; Focal mechanism; Theoretical seismology
• ISSN: 1383-4649; 1573-157X
• DOI: 10.1007/s10950-020-09951-2

Moment tensor decomposition is a method for deriving the isotropic (ISO), double-couple (DC), and compensated linear vector dipole (CLVD) components from a seismic moment tensor. Currently, there are two families of methods, namely, standard moment tensor decomposition and Euclidean moment tensor decomposition. Although both methods can usually provide workable solutions, there are some minor inconsistencies between the two methods: an equality inconsistency that occurs in standard moment tensor decomposition and the pure CLVD unity and flip basis inconsistency encountered in Euclidean moment tensor decomposition. Moreover, there is a sign problem when disentangling the CLVD component from a DC-dominated case. To address these minor inconsistencies, we propose a new moment tensor decomposition method inspired by both previous methods. The new method can not only avoid all these minor inconsistencies but also withstand deviations in ISO- or CLVD-dominated cases when using source-type diagrams.