Sub-surface magma movement inferred from low-frequency seismic events in the off-Nicobar region, Andaman Sea

This study presents Ocean Bottom Seismometer (OBS) data providing geophysical evidence of subsurface magmatism along submarine volcanoes in the off Nicobar region, Andaman Sea. The researchers observed hybrid very long-period earthquakes, characterized by high-frequency onset followed by low-frequency oscillations and a hydro-acoustic phase. These events, concentrated along the submarine volcanic arc and Seulimeum strand of the Great Sumatra fault, suggest subsurface tectonic and magmatic influence, with upward magma movement potentially activating strike-slip movement and inducing earthquake swarms.

K. K. Aswini, Pawan Dewangan, K. A. Kamesh Raju, V. Yatheesh, Pabitra Singha, Lalit Arya, T. Ramakrushana Reddy