A Novel Passive Seismic Imaging Workflow for Volcanic Regions with Irregular Source–Receiver Coverage

Summary Understanding the complex subsurface structures in volcanic regions is crucial for effective hazard assessment and resource management. In such areas, traditional active seismic studies often require substantial human and material resources. In the contrary, passive seismic data offers a valuable alternative by making use of the extensive seismic records accumulated over time, which simplifies data acquisition and significantly reduces costs. This study aims to develop a workflow for processing passive-source seismic data with irregular source-receiver distributions, identifying reflection phases to produce a seismic profile suitable for passive-source seismic reflection imaging. To achieve this, we then simulate 400 micro-earthquakes, randomly distributed between 1 and 3 km in depth, and recorded by 13 stations. Then, we apply several preprocessing steps to both synthetic and real seismic data to ensure high-quality imaging results. Finally, reflection phases are carefully identified by utilizing the predicted theoretical arrival times of both reflected and converted phases. Through this processing procedure, we ultimately generate a passive-source seismic profile with irregular source-receiver distributions, suitable for migration imaging.