Since the early 1950s, Greece has been a popular travel destination providing high-quality tourism services. This was amplified by its diverse landscape, extended sandy beaches, scattered archaeological sites, people’s mentality, and adequate infrastructure. In particular, the south Aegean Archipelago attracts more than six million (6,000,000) visitors annually, approximately 27% of tourist arrivals in Greece. The carrying capacity assessment of the South Aegean region aims to improve the already high standards of the offered tourist services. Seventeen appropriate variables were analyzed to assess and increase tourism attractiveness by alternative products for long-term and sustainable management. Furthermore, the outcomes of the carrying capacity indicators application provide specialized solutions to control the over-tourism impact, mitigate the natural environmental degradation, and establish a roadmap for sustainable development in the study area. The required data were interpreted based on the PAP/RAC 1997 and WTO, enriched with more suitable variables from national and international literature to determine the carrying capacity. Therefore, the selection of seventeen (17) most representative indicators was unavoidable. Finally, the calculation of the different indexes showed that Mykonos and Thira are far above the indicator scale limits and are facing over-tourism issues. Additionally, the numbers of tourists concentrated in the abovementioned islands may accelerate the environmental degradation and, as a result, the tourist product will be downgraded. The set of these seventeen indicators works best since low, obfuscated, or no environmental data are available for the South Aegean region from the official state agency. Alternative tourist development and the extension of the tourist season based on local climatic conditions must be applied to ease the over-concentration and, consequently, the degradation of the tourist product. The large islands do not seem to face significant problems. However, the calculation of CCA will contribute to the decongestion of tourism concentration together with environmental decompression, leading to sustainable development in the South Aegean region.

The Arkalochori village in central Crete was hit by a large earthquake (M_w = 6.0) on 27 September 2021, causing casualties, injuries, and severe damage to the infrastructure. Due to the absence of apparent surface rupture and the initial focal mechanism solution of the seismic event, we initiated complementary, multi-disciplinary research by combining seismological and remote sensing data processing, followed by extensive field validation. Detailed geological mapping, fault surface measuring accompanied with tectonic analysis, fault photorealistic model creation by unmanned aerial system data processing, post-seismic surface deformation analysis by DInSAR image interpretation coupled with accurately relocated epicenters recorded by locally established seismographs have been carried out. The combination of the results obtained from these techniques led to the determination of the contemporary tectonic stress regime that caused the earthquake in central Crete, which was found compatible with extensional processes parallel to the Hellenic arc.

The foreseeable acceleration of global sea level rise could potentially pose a major threat to the natural charm and functional integrity of the world-renowned tourist coastal attractions of Rhodes Island, as a result of the anticipated increasing frequency of flooding and erosion events. Hence, this study aims to determine the most vulnerable segments (in terms of physical impact) of the Rhodes coastline through the widely accepted coastal vulnerability index (CVI), applying a combination of well-known, broadly used approaches and methods. The frequency distribution of the current CVI along the island’s coastline suggests a rather worrying high to very high vulnerability of 40%. In addition, a CVI projection to the end of the 21st century (based on the Intergovernmental Panel on Climate Change predictive scenarios) indicates an enhancement of the total vulnerability by 48%, mainly focused on the majority of the western coastline. Hence, a considerable number of popular coastal destinations in the island shall remain under unignorable threat and, therefore, coastal managers and decision-makers need to hatch an integrated plan to minimize economic and natural losses, private property damage and tourism infrastructure deterioration from flooding and erosion episodes, which will most likely be intensified in the future.

Research infrastructures have been established throughout Europe in order to create robust organizations that will facilitate and enhance research and innovation processes and will advance society with innovative products and services. The Hellenic Integrated Marine Observing, Forecasting and Technology System (component of HIMIOFoTS RI) has been implemented in the framework of the National Roadmap for Research Infrastructures to form a large-scale infrastructure for the marine environment in Greece. It links together ocean observing and forecasting systems, coastal zone monitoring and management practices, as well as ocean engineering testing facilities. The overarching framework of the system supports the coordination of five organizations with expertise in the field of marine science and technology, the central management of research activities, and the common development of services and products. It comprises facilities and resources while it provides open access to research communities (academia, industry) to support the scientific advancements and innovation in their fields. The Hellenic Marine Observing, Forecasting and Technology System was further enhanced during its implementation through significant upgrades and developments in order to extend its observing capacity and the forecasting and technological abilities, while advancing the provided services and products.