Unveiling attenuation structures in the northern Taiwan volcanic zone.

Area of Science:

• Geophysics
• Seismology
• Volcanology

Background:

• Taiwan is situated at a complex tectonic boundary between the Philippine Sea and Eurasian Plates.
• The region exhibits moderate seismicity and notable volcanic activity, particularly the Tatun volcano group.

Purpose of the Study:

• To investigate regional magmatism in northern Taiwan using advanced geophysical methods.
• To identify subsurface structures associated with volcanic and tectonic processes.

Main Methods:

• Utilized 3-D P- and S-wave frequency-dependent attenuation tomography.
• Employed the Formosa seismic array for high-resolution data acquisition.

Main Results:

• Identified high-attenuation anomalies (low Q) beneath the northern Taiwan volcanic zone and offshore volcanoes, suggesting hydrothermal activity and magma.
• Detected low-attenuation anomalies (high Q) in the Ryukyu subduction zone forearc, possibly due to serpentinization from seawater infiltration or mantle hydration.

Conclusions:

• The study provides crucial insights into the crustal properties and magmatic evolution of northern Taiwan.
• Findings contribute to a deeper understanding of the interplay between subduction, volcanism, and fluid dynamics in the region.