Local and duration magnitude scales for northern Algeria based on local earthquake data (2010-2022)

Abstract

he study of earthquake magnitudes plays a crucial role in understanding seismic events, their impacts, and the tectonic processes that shape our planet. Earthquake magnitudes, as numerical measures of an event’s size, provide valuable information about the energy released during an earthquake, helping to assess the event’s potential for damage and guiding seismic hazard assess-ments. Over time, several magnitude scales have been developed to address different types of seis- mic waves and varying distances from the earthquake source. These include the Local Magnitude (ML), Surface Wave Magnitude (Ms), Body Wave Magnitude (mb), and Moment Magnitude (Mw),each with its advantages, limitations, and suitable applications. In northern Algeria, a region proneto seismic activity due to its complex geodynamics and seismotectonic setting, accurate magnitude determination is essential. The Local Magnitude (ML) and Duration Magnitude (Md) scales are of particular importance for characterizing earthquakes within the region. The ML scale, developed by Charles Richter in the 1930s, remains one of the most widely used scales, particularly for small to moderate local earthquakes. Meanwhile, the Md scale, which measures the duration of seismic waves, provides an important supplement to ML, especially for larger and deeper earthquakes. Un- derstanding these scales and their applications in northern Algeria is vital for earthquake hazard mitigation, infrastructure planning, and public safety. This thesis aims to explore and refine thecalculation and use of magnitude scales, specifically focusing on the Local Magnitude (ML) and Duration Magnitude (Md) scales, in the context of northern Algeria. By developing a comprehen- sive understanding of these scales, this study contributes to the ongoing efforts to enhance seismic monitoring and improve earthquake magnitude estimation techniques in the region.