The COSMOS–ESG7 mHVSR Pre-Event Forum is a full-day international gathering convened by the Consortium of Organizations for Strong-Motion Observation Systems (COSMOS) on the eve of the 7th IASPEI/IAEE International Symposium on the Effects of Surface Geology on Seismic Motion (ESG7), to be held in Grenoble, France, 19–21 October 2026.
The Forum brings together leading researchers, practitioners, and engineers from around the world to advance the state of knowledge, art, and practice in microtremor Horizontal-to-Vertical Spectral Ratio (mHVSR) analysis for evaluating seismic site response.
Building on discussions at the April 2026 SSA Annual Meeting Special Session in Pasadena and on ongoing monthly mHVSR meetings, this Forum is intended to serve as a focused pre-symposium platform for structured debate, community benchmarking, and the development of international guidelines, e.g., the Site EffectS assessment using AMbient Excitations (aka: SESAME v.1.0, 2004) — a "SESAME 2.0" for the modern era.
Context: ESG7 Symposium
The 7th IASPEI/IAEE International Symposium on the Effects of Surface Geology on Seismic Motion (ESG7) will be held 19–21 October 2026 in Grenoble, France. ESG7 explores all facets of site effects on ground motions, including blind prediction exercises on topographic effects and H/V inversion benchmarks. The COSMOS–ESG7 mHVSR Forum is scheduled as a dedicated pre-event on Sunday, 18 October 2026.
Key Topics of the mHVSR Forum
· State of knowledge and practice for mHVSR analyses
· Estimation of fundamental (f₀) and dominant (fd) site frequencies
· Epistemic and aleatoric uncertainties in mHVSR-based site response
· Inversion of mHVSR for shear-wave velocity (VS) profiles and a priori parametric requirements
· Performance and limitations of low-cost sensors for HVSR
· mHVSR characteristics in complex media (e.g. lateral heterogeneity, basin edge effects, 2D resonances)
· International benchmark and new guidelines ("SESAME 2.0")
Organising Committee
Cécile Cornou
Université Grenoble Alpes, France
Aysegül Askan
COSMOS Board of Directors; Middle East Technical University, Ankara, Turkey
Shinichi Matsushima
COSMOS Board of Directors; Kyoto University, Japan
Alexandros Savvaidis
COSMOS Board of Directors; The University of Texas at Austin, USA
Alan Yong
U.S. Geological Survey, USA
Forum Speakers
Francisco Sánchez-Sesma (UNAM) · Jonathan Stewart (UCLA) · Brady Cox (Utah State Univ.) · Joseph Vantassel (Virginia Tech) · Sheri Molnar (UWO) · Albert Kottke (PG&E) · Adrian Rodriguez-Marek (Virginia Tech) · Behzad Hassani (BC Hydro) · Kenneth Hudson (Hudson Geotechnics) · Antony Martin (GeoVision) · Silvia Castellaro (Univ. Bologna) · Marco Pilz (GFZ) · Giovanna Cultrera (INGV) · Fabian Bonilla (Univ. Gustave Eiffel) · Stefano Parolai (Univ. Trieste) · Koichi Hayashi & Hiroshi Kawase (Kyoto Univ.) · Liam Wotherspoon & Chris de la Torre (New Zealand) · and others (TBA).
Registration & Information
This forum is held in conjunction with ESG7 and is open to all registered participants. Attendance is free of charge for ESG7 registrants.
ESG7 Symposium: 19–21 October 2026, Grenoble, France
Forum date: Sunday, 18 October 2026 (full day)
COSMOS: www.strongmotion.org
ESG7: esg2026.inviteo.fr