Abstract

We interpret the legacy ship-track magnetic and bathymetric profile data to investigate the role of the lithospheric scale West Andaman Fault (WAF) in the dormant Narcondam and active Barren Island volcanoes. We use data-based automated interpretation of total magnetic intensity (TMI) profiles using a contact model in order to delineate geometrical and physical parameters of several faults including the WAF and then investigate its implications in recent volcanism at the Barren Island. Our data-based interpretation of TMI data requires transformation of it into the first order analytical signal and tilt angle, which in turn, requires estimation of the first order horizontal and vertical derivatives of TMI data. We ensure robust estimation of the first order horizontal and vertical derivatives using Savitzky–Golay derivative filter and Hilbert–Noda transformation, respectively. We have identified several anomaly segments of the TMI anomaly profiles and used data-based quantitative interpretation in each segments with a contact model. We then make a comprehensive interpretation using bathymetry, geological setup and the results from quantitative data-based interpretation of magnetic data, and ascertain possible role of the WAF in Barren Island volcanism.

Research highlights

• Quantitative data based interpretation of magnetic profiles across Narcondam and Barren Island seamounts.

• Quantitative data based interpretation is based on analytical signal and tilt angle based transformation of magnetic data and modelling with a contact model.

• Architectural settings of the West Andaman Fault are delineated and its implication in recent Barren Island volcanism is discussed.

• A transpression signature of the West Andaman Fault near Barren Island volcano is identified.

中文翻译：

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再次对Narcondam和Barren Island火山附近的航迹磁数据进行解释

摘要

我们解释了传统的航迹磁测深数据，以研究岩石圈规模的西安达曼断裂（WAF）在休眠的纳孔丹和活跃的巴伦岛火山中的作用。我们使用接触模型使用基于数据的总磁强度（TMI）剖面自动解释，以描绘包括WAF在内的几个断层的几何和物理参数，然后研究其在Barren Island火山活动中的意义。我们对TMI数据的基于数据的解释要求将其转换为一阶分析信号和倾斜角，进而需要估算TMI数据的一阶水平和垂直导数。我们确保分别使用Savitzky-Golay导数滤波器和Hilbert-Noda变换对一阶水平和垂直导数进行可靠的估计。我们已经确定了TMI异常概况的几个异常段，并在每个段中使用了基于数据的定量解释与联系模型。然后，我们使用测深法，地质构造以及基于定量数据的磁数据解释的结果进行全面的解释，并确定WAF在巴伦岛火山活动中的可能作用。

研究重点

• 基于定量数据的Narcondam和Barren Island海山的磁剖面解释。

• 基于定量数据的解释基于分析信号和基于倾角的磁数据转换以及使用接触模型进行建模。

• 描绘了西安达曼断裂的建筑环境，并讨论了其在最近的巴伦岛火山活动中的意义。

• 确定了巴伦岛火山附近的西安达曼断层的压转特征。