The Multichannel Analysis of Surface Waves Method (MASW): Brief Theory and Application to Near Fault Zone Identification

Abstract

The characterisation of near subsurface geological features such as sedimentary layer thickness distribution and
near-surface geological structures are interest and continues to be studied to understand the complete conditions in the
subsurface. One geophysical method that can be used for characterising shallow targets is the Multichannel Analysis
of Surface Waves (MASW) method. The MASW method is a method that utilises the dispersive nature of surface waves
to model the shear wave velocity distribution in each layer vertically (Vs-depth model). The MASW method consists of
three stages: acquisition, processing, and inversion. In this paper, we describe the general concept/theory of MASW
and its application to characterise a shallow fault zone at a target depth of about 150 m in the active zone, Iberian
Peninsula, Spain. This study is supported by trenches data as a marker for the fault plane in the study area. Based
on the study and results obtained in this paper, it is hoped that it can provide a brief theory regarding the MASW
method for the benefit of learning and advancing science and technology in Indonesia. Moreover, it is also hoped
that the application of the MASW method in Indonesia will continue to develop and can be used with wider interests.