The seismic hazard generated by faults slipping in large earthquakes and the need to mitigate the risk for nearby exposed populations and infrastructures requires scientists to seek a better understanding of the physics of faulting and the near-surface response to earthquake shaking. However crustal faults are complex natural systems whose mechanical properties evolve over time. Furthermore, the faults act as network of pathways through which fluids of different origin (primordial, biogenic, radiogenic decay etc.) move towards the surface transferring traces of the physic-chemical processes that are relate to variation of the crustal field of stress. Thus, the understanding of the multi-scale, physical/chemical processes responsible for earthquakes and faulting requires considering phenomena that intersect different research fields (the road of integration). Modern observatories realized near active faults, provide innovative research approaches based on multidisciplinary networks (e.g., geochemical, geophysical, surface deformation) continuously monitor the underlying earth instability processes over a broad time interval (Yuce et al., 2010; Chiaraluce et al., 2014). Within this context, earthquakes, especially those occur nearby metropolitan areas and high-populated areas, are disasters for human beings. China, Italy, Iran, Turkey and Greece are countries located along the seismic belt, with big cities and huge population under threat of earthquakes. Accordingly, these countries have earned solid foundation in the field of earthquake forecasting, particularly by monitoring seismic fluid geochemistry anomalies. In China, the Tibetan plateau and its adjacent regions are also earthquake-prone areas where China Seismic Experimental Site (CSES) was set up specifically by Chinese government, and relevant fluid geochemistry studies have also been carried out with purpose. In Italy, researchers have conducted fluid geochemistry studies along the entire national territory with multiple technical methods for a long time (decades) in response to the frequent volcanic and seismic activities. In Italy seismicity is distributed over the national territory from south to north and during the last years the areas of the high magnitude earthquakes (e.g., Central Appennine) are investigated by using the approach of the near fault observatory (NFO). Hence there two NFOs have been created and implements and two new ones are in developing. Apart from China and Italy, other countries, for example, Iran, Turkey and Greece have also faced many catastrophic earthquakes at past (Tan et al., 2008; https://deprem.afad.gov.tr/depremkatalogu?lang=en).
Fluid geochemistry anomalies related to occurrence of earthquakes have been found by large number of researches (e.g., Wakita et al., 1980; Igarashi and Wakita, 1990; Italiano et al., 2009; Roeloffs, 1999; Koike et sl., 2015; Tuccimei et sl., 2015; Girault et al., 2017; Y?ld?r?m et al., 2020), and a preliminary genetic model for these anomalies are proposed. Since the 1970s, due to the rapid development of analytical methods and monitoring technologies, seismic fluid geochemistry is confronted with challenges as well as opportunities (Irwin & Barnes, 1980; He et al., 2011; Karlstrom et al., 2013; Minissale et al., 2018; Chen et al., 2017). On the one hand, increasing number of studies show that there are internal relations in time and space between the fluid geochemistry anomalies in active fault zones and the tectonic activity and seismicity (e.g., Caracausi et al., 2004 and 2013; ; Evans et al., 2007; Italiano et al., 2009; Caracausi and Sulli, 2019; Barberio et al., 2019). On the other hand, problem that the low efficiency of earthquake forecasting by seismic fluids cannot meet the demand of minimizing earthquake disasters becomes prominent with the continuous earthquake forecasting practices (Woith et al., 1998; Toutain & Baubron, 1999; Martinelli & Dadomo, 2017). The fundamental reasons lie in: (1) the lack of systematic and objective cognition on the genetic mechanism of seismic fluid anomalies, and (2) the present theories on earthquake forecasting by seismic fluids and relevant monitoring methods are not perfect. The recent advancements in technologies to be used in the field are allowing the worldwide scientific communities to perform high frequency monitoring of geochemical parameters and their transmission in real time in order to be stored in databases. This permits to observe the evolution of some processes (e.g., water-gas-rock interactions) that occur during the variation of the field of stress of the volume of rocks that are associated to earthquakes. Furthermore, the new technological advancements are also contributing to carry out new experimental works for the understating of the relationships between fluids and the deformation of rocks in order to understand and quantify possible signals/anomalies that the fluids can record and transfer to the surface.
So, this project is intended to make some breakthroughs through the international cooperation between Italy and China and the two main national institutes that are involved in earthquake forecasting.
