The inversion of deep‐sea magnetic anomalies using Akaike's Bayesian information criterion

Abstract

[1] We present a magnetic inversion method in the space domain using Akaike's Bayesian information criterion (ABIC). The horizontal variation of magnetization intensity is represented by a linear combination of bicubic B spline functions, and the problem is set to determine the expansion coefficients. A prior constraint on the roughness of the magnetization variation is incorporated in order to suppress the numerical instability. The ABIC give us the optimal weight of the prior constraint relative to the requirement of fitting the observed data, which is statistically determined from the quality and quantity of the data based on the entropy maximization principle. We applied this method to actual deep-sea magnetic data collected by using an autonomous underwater vehicle and successfully obtained a magnetization distribution that adequately accounts for the observation. The solution does not suffer from the inevitable smoothing due to high-cut filtering or an error caused by reducing the data onto a flat surface as sometimes happens in current inversion methods. Our method is especially useful in handling data collected along a surface of extreme topography over a relatively small area.Citation: Honsho, C., T. Ura, and K. Tamaki (2012), The inversion of deep-sea magnetic anomalies using Akaike's Bayesian information criterion,

Deep‐sea magnetic vector anomalies over the Hakurei hydrothermal field and the Bayonnaise knoll caldera, Izu‐Ogasawara arc, Japan

“…[16] The vector anomaly data obtained for this study were used as input for the magnetic inversion using Akaike's Bayesian Information Criterion (ABIC) [Honsho et al, 2012], based on the inversion method developed by Akaike [1980] and Yabuki and Matsu'ura [1992]. We first made the same assumptions regarding the magnetic source as Parker and Huestis [1974]: a magnetic layer of a constant thickness whose upper surface is constrained by the seafloor, a constant magnetization direction and no intensity variation with depth.…”

Structural characteristics of the Bayonnaise Knoll caldera as revealed by a high-resolution seismic reflection survey

“…The results of a deep sea magnetic survey, which was conducted using autonomous underwater vehicles, also revealed a high-magnetic anomaly on the caldera wall (Honsho et al 2010(Honsho et al , 2012(Honsho et al , 2013 This implies the existence of a fault in this part. Figure 4b presents a detailed bathymetry map around the Bayonnaise Knoll caldera that was constructed along the MCS survey line.…”

“…Input of water may also occur around the caldera. Honsho et al (2010Honsho et al ( , 2012 present the distribution of the magnetic anomaly, and these data likely correspond to the hydrothermal deposit (Figure 4). They also suggest that the magnetic anomalies are distributed along the inferred fault with a north-south trend.…”

High‐resolution magnetics reveal the deep structure of a volcanic‐arc‐related basalt‐hosted hydrothermal site (Palinuro, Tyrrhenian Sea)

“…We use the inversion method developed by Honsho et al . [] based on the Akaike Bayesian Information Criterion (ABIC) which, unlike other inversion methods, is achieved along the uneven tracks of the vehicle in the space domain, i.e., it does not require the data to be acquired on a datum plane. In this method, the magnetization distribution is estimated by a linear combination of bicubic splines and we aim to determine their expansion coefficients.…”