The SEISMAZE project is aimed at using observations of low-frequency seismic tremors and earthquakes to get information about active geological processes and are used in most monitoring systems of hazardous geological phenomena such as volcanoes and earthquakes.

Traditional seismological approaches focus on ‘regular’ earthquakes, i.e., impulsive events that are generated by rapid slip on faults. Earthquake detection and location, together with the determination of magnitudes and source parameters, are performed by the many organizations that are responsible for monitoring of seismicity, volcanic eruptions, tsunamis, and other such events.
However, these methods explore less than a few percent of the available seismological records, and they are not the most suitable for observation of the wide range of ‘slow’ transient energy-release processes that occur during the preparation phases that precede major earthquakes and volcanic eruptions. One of the most important challenges in seismology is to explore the full wealth of information provided by continuously operating seismic networks.

An important part of the continuous seismic records is a broad family of so-called ‘slow’ seismic events that span a wide range of duration and amplitude scales. This includes tremors (e.g., weak, long-duration and low-amplitude, nonstationary signals), low frequency earthquakes (LFEs) (e.g., short duration, impulsive signals) and very-low frequency earthquakes (VLFEs). These seismic signals are one of the main manifestations of the slow transient energy release (STER) processes that accommodate the mechanical evolution of geologically active systems under slow large-scale forcing prior to and after cataclysmic energy release during volcanic eruptions or strong earthquakes. They provide, therefore, a new paradigm for studying active geological processes in a variety of tectonic settings and for improving monitoring methods of seismic and volcanic hazards. An accurate interpretation of this type of seismological information requires developing new detection and source restoration methods together with profound physical understanding of the relationship between these different events and underlying STER processes.

The main goal of the SEISMAZE project is to develop a new unified framework for the analysis of the seismic signatures of STER processes, and to systematically apply this to major datasets from different active volcanic and tectonic regions, in order to decipher the slow transient physical processes that occur in active geological systems during the preparation periods that precede major volcanic eruptions and earthquakes. This will improve our understanding of the multi-scale slow transient energy release mechanisms, and of their interactions, that control the evolution of volcanic and tectonic systems towards cataclysmic events. The following scientific questions are addressed:

• What are the mechanisms and physical processes that produce tectonic and volcanic seismic tremors, and how are the energy release processes at different temporal and spatial scales are related?
• What physics governs the transition from slow to fast transient energy release, and how do these processes contribute to the preparation of major volcanic eruptions and earthquakes?
• How can the STER seismic signals be used to characterize the structure and state of volcanic systems and seismogenic faults?
• What mechanisms control the migration at different time and spatial scales of the various forms of STER processes, and their potential triggering by various external stress disturbances?

The results of the proposed research will be used to develop a new generation of monitoring methods, through the combination of data-driven and physics-based methods exploiting adaptive stream-based analysis of continuous seismological records from increasingly dense arrays. It will also promote young researchers working on data-intensive research in seismology.