## 13 Discussions and Conclusions Regarding Gaps and Areas of Improvement in the System  
The key operational functions of a tsunami warning center are to provide real-time monitoring and seismic and tsunami activity alerts and to allow timely decision-making and the dissemination of tsunami warnings, advisories and information. The chain begins with data collection and ends with saving lives [40]. Despite the efforts made to establish an end-to-end tsunami warning system in Turkey, meaningful progress has only been made for the upstream system component. There is simply no real operational capability of the Civil Protection Authority of Turkey (AFAD) to analyze and forward tsunami warning messages received from KOERI-TSP to its local units and the public or to warn the public directly in cases of tsunamigenic events. However, the 30 October 2020 Samos earthquake and resulting tsunami effecting the southern coasts of the Izmir peninsula appears to be milestone in this aspect. A direct emergency telephone line was established in 2021 between RETMC and AFAD to allow verbal communication between agencies in case of a tsunami alert, and efforts are underway by the AFAD to establish a nationwide integrated warning and alarm system as part of a wider disaster management and decision support system. While it is obvious that an effective tsunami warning system can be achieved only through various awareness, education, preparedness and mitigation activities, focusingon the downstream components of the system, such elements are beyond the scope of this paper. The current distribution and density of tide gauges could be very problematic for the verification of a tsunami after an earthquake, as experienced during the tsunami observations after the 30 October 2020 Samos earthquake. The difficulties in identifying the authenticity and reliability of eye witness observations distributed through the social media after a natural disaster add to this gap. This gap is even bigger around the southern coasts of the Mediterranean, requiring urgent action towards international agreements for the densification of tide gauges wherever possible. Such systems could also be designed from a multi-hazard perspective to ensure efficiency, sustainability and usability by various scientific and operational actors involved in natural disasters. There is also an urgent need for the deployment of offshore tsunami measurement systems, involving either ocean bottom pressure gauge or GPS buoy systems at optimum locations, as demonstrated in [41]. It is obvious that all TSP warning messages are subject to uncertainties related to the derivation of earthquake parameters and the decision support systems themselves, especially for decision-matrix based systems where a 0.1 unit change in the earthquake magnitude may drastically change the threat level to the assigned regions. The impacts of such a situation were easily observed during the 30 October 2021 Samos earthquake. The initial tsunami warning message disseminated by KOERI indicated a Mw 7.0 earthquake (also the final Mw published by the USGS), while the final Mw determined was Mw 6.9. As can be seen from Figure 6, the initial warning disseminated based on a Mw 7.0 event puts the whole Aegean Sea under the highest alert level. A tsunami warning message based on a Mw 6.9 event (Figure 7), if calculated at the time of the issuance of the initial message, would correspond quite accurately to the actual impact of the generated tsunami. Offshore and coastal wave amplitudes for both cases derived from the MOD2-TR tsunami scenario database [20; 21] are presented in Figure 10, clearly showing differences in comparison to the cases presented in Figures 6 and 7. This demonstrates the added value of making use of pre-calculated tsunami scenario databases for the purposes of tsunami warnings. However, the results available from pre-calculated tsunami scenario databases or near-real-time tsunami modeling may still carry uncertainties associated with the source of the tsunami.