Paleotsunami research is critically important in helping to understand low frequency but large tsunamis. It is also useful for tsunami risk assessments. However, there are many remaining research questions and issues. To help address these questions and issues, post-tsunami geological surveys, which are carried out soon after an event has occurred, are a key to understanding the sedimentary characteristics of tsunamis as modern analogues. Post-tsunami geological surveys are also useful for helping in the recovery process of the local government and the people. In order to perform an efficient post-tsunami geological survey, issues and points that all researchers should be aware of are summarized here. This paper is also useful as a survey manual for paleotsunami and post-tsunami geological surveys both for experts and for non-experts.
Cascading geohazards represent a critical threat in tectonically active regions. This study, carried out within the framework of the BARACA project, investigates the role of landslides in cascading geohazards within the Betic-Alboran-Rif shear zone of the Western Mediterranean. It applies a multidisciplinary approach that integrates marine and terrestrial geology, geophysics, and numerical modelling. It presents three case studies analyzing how active faults can trigger landslides with tsunamigenic potential. First, the semi-submerged El Arrecife landslide in the Rules Reservoir (Betic Cordillera) is analyzed. Simulations indicate that a moderate earthquake under saturated conditions could trigger a sudden collapse, generating a 46-meter impulse wave capable of overtopping the dam. Second, in the South-Central Alboran Sea, the Al-Idrisi, Incrisis, and Averroes fault system zones are identified as key zones where seismic activity appears to drive recurrent submarine landslides, enhancing tsunamigenic potential beyond fault rupture alone. Finally, the Taoussart coastal landslide (Rif Cordillera) is examined, revealing high susceptibility to coseismic activation driven by rapid tectonic uplift, steep slope, and coastal erosion. These findings underscore the necessity of integrated assessments to understand cascading mechanisms where landslides constitute a main link and to improve early warning systems and risk mitigation strategies in tectonically active regions.
