Relationships Between Mw and Other Earthquake Size Parameters in the Spanish IGN Seismic Catalog

Resumen

In the recent seismic hazard assessment study of Spain, a crucial step in preparing and standardizing the seismic catalog involves establishing relationships among various scales used to measure earthquake size. The aim is to convert all earthquake size data from the original catalog into a single magnitude scale, specifically the moment magnitude (Mw). This ensures uniform and comparable size measurements across the dataset.

To achieve this, new relationships between Mw and other magnitude scales used in the catalog are developed through regression analysis. This analysis is conducted across different epochs, allowing for a comprehensive understanding of seismicity trends over time. The reduced major axis regression scheme is employed for its symmetric treatment of variables involved in the fits, ensuring robustness in the derived relationships.

The study presents the newly derived relationships for Spain, including Mw as a function of mbLg, Mw as a function of mb, and Mw as a function of Imax. The applicability limits and accuracy of these relationships are thoroughly discussed to provide insights into their reliability and utility in seismic analysis. Importantly, beyond their immediate application in seismic hazard assessment, these results could have broader practical implications in regional seismicity analysis, offering valuable tools for earthquake research and risk management initiatives.