Abstract

Barren Island volcano (BIV), India has started erupting vigorously from 2018 after a gap of 13 years (last active period 2004–2005) just after the 2004 tsunami. Although there is evidence of coupling between seismicity and earthquake in this region, it is not thoroughly researched. Here, we present satellite-based approach to monitor and understand the volcano dynamics w.r.t. associated seismicity at BIV using multispectral datasets, ~20 yrs Volcanic Radiative Power (VRP) and ~70 yrs historical earthquake data (1950–2020 July). The rate of frequency of earthquake has increased to 3.54 times during 1990–2020 as compared with 1950–1989 which signifies seismicity-induced pressure release that may have caused decompression in the region, leading to eruptions or at least modulation of the eruption. The VRP results clearly depicted the changes from low to high thermal regimes that indicate switching from open-vent to effusive activity of Barren Island volcano. The historical data of recent times show correlation of seismic and volcanic activities. The spatial-temporal distributions of earthquake swarm are not associated with volcano, but are clustered near the tectonic regimes. The volcanic activity is preceded by seismic activity along the regional tectonic structures. In addition, the 2018 eruptive phase has been analyzed for better understanding of the proposed event. The present research has provided significant supportive evidences to give adequate credence to this emerging hypothesis and also revealed the location of primary, secondary vents, flow tracts and all evolving volcanic landforms of the region and recorded the changes in flow directions. Further, for a comprehensive risk assessment of the region, volcanism, seismicity, and coastal dynamics along with crustal deformation need to be considered.

Research highlights

• The study has analyzed the eruption of Barren Island volcano and associated regional seismic activity from a Multi-Hazard perspective using satellite as well as field-based observations.

• These results provided stronger supportive evidences for coupling seismicity and volcanic eruptions at Barren Island volcano for the first time in this region and open up new vistas for research in this direction.

  The understanding of these two natural phenomena is very much needed for better preparedness with respect to disaster risk mitigation and management.

中文翻译：

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荒岛火山活动和地震活动：一个有趣的发现

摘要

印度的贫瘠岛火山 (BIV) 在 2004 年海啸之后间隔了 13 年（最后一个活跃期 2004-2005 年），从 2018 年开始猛烈喷发。尽管有证据表明该地区地震活动与地震之间存在耦合，但尚未对其进行深入研究。在这里，我们提出了基于卫星的方法，使用多光谱数据集、~20 年的火山辐射功率 (VRP) 和~70 年的历史地震数据（1950-2020 年 7 月）监测和了解 BIV 与地震活动相关的火山动力学。与 1950 年至 1989 年相比，1990 年至 2020 年的地震频率增加到 3.54 倍，这表明地震活动引起的压力释放可能导致该地区减压，导致喷发或至少调制喷发。VRP 结果清楚地描绘了从低热状态到高热状态的变化，表明 Barren Island 火山从开放式火山活动转变为喷发活动。近代的历史资料显示地震和火山活动的相关性。地震群的时空分布与火山无关，而是聚集在构造体制附近。火山活动先于区域构造构造的地震活动。此外，还分析了 2018 年的喷发阶段，以便更好地了解拟议的事件。目前的研究提供了重要的支持性证据来充分证实这一新出现的假设，并揭示了初级、次级通风口的位置，流域和该地区所有演变的火山地貌，并记录了流向的变化。此外，为了对该地区进行全面的风险评估，需要考虑火山活动、地震活动和海岸动力学以及地壳变形。

研究亮点

• 该研究使用卫星和实地观测，从多灾害的角度分析了贫瘠岛火山的喷发和相关的区域地震活动。

• 这些结果为该地区首次在巴伦岛火山上耦合地震活动和火山喷发提供了更有力的支持证据，并为该方向的研究开辟了新的前景。

  非常需要了解这两种自然现象，以便在减轻和管理灾害风险方面做好更好的准备。