CRater ACoustics - In Non-symmetrical Geometry: Determining the influence of volcanic crater asymmetry, jet flow and edifice topography on acoustic resonant modes and frequency radiation characteristics.

• Applicant: Dr. Julia Elisabeth Gestrich, Ph.D.
• Subject Area: Geophysics
• Term: since 2026
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 578962744

The objective of this project is to advance our understanding of acoustic resonances in volcanic craters by systematically disentangling the roles of geometry and internal flow dynamics. Volcanic acoustic signals carry critical information about eruption dynamics, yet current models struggle to explain the spectral features observed in field data, especially in complex and asymmetric crater geometries. A fundamental knowledge gap exists in how crater shape and eruptive flow structures modulate the resonant modes of an open cavity and influence the directionality of the emitted sound. Furthermore, the impedance boundary condition at the crater opening, a key parameter in wave propagation models, remains poorly constrained in natural settings. This project aims to bridge these gaps by combining controlled laboratory experiments, targeted field campaigns, and numerical simulations to characterize the modal structure of crater acoustics under increasingly realistic conditions. The results will improve our capability to interpret volcanic infrasound, providing a foundation for future eruption monitoring of volcano observatories and source inversion techniques.

• DFG Programme: Research Grants
• International Connection: New Zealand
• Co-Investigators: Dr. Ulrich Küppers; Professor Dr. Jörn Lothar Sesterhenn
• Cooperation Partner: Professor Dr. Leighton Watson