8 research outputs found
Earthquake-Induced Tsunamis in Western Greece (Ionian Sea and Western and Southern Peloponnese): Use of Tsunami Quantities, Impact and ITIS-2012 Intensities for Highlighting Susceptible Areas
Taking into account recent studies on the tsunamigenic potential of strike-slip faults, it is concluded that there is a need to reassess their near-source tsunami hazard and risk. One of the areas which needs reassessment is Western Greece, especially the Ionian Islands and the western coastal Peloponnese, where major seismogenic strike-slip structures occur. In this context, an extensive review of the available literature is conducted, including not only earthquake and tsunami catalogues but also tsunamis’ imprints on the stratigraphic record. It is concluded that the Ionian Islands and the western Peloponnese have a rich history of tsunamis since 6000 BC, revealing that they are subjected to high tsunami hazard. In addition to the teletsunami effects of distant earthquakes, there are also local tsunamis with smaller physical quantities and slighter coastal impact that are attributed mainly to local offshore faults and earthquake-triggered landslides. The fact that no destructive local tsunamis have been detected so far does not exclude the possibility of future triggering. In order to identify areas susceptible to future tsunami impact, we extract tsunami quantities and coastal impact data from available sources and we apply the Integrated Tsunami Intensity Scale 2012 (ITIS-2012) for all the events with available and adequate information. The highly susceptible areas comprise straits, funnel-shaped bays and extensive coastal areas exposed to major strike-slip seismogenic sources in the Ionian Sea and the western Hellenic Trench. Based on the aforementioned information, the inclusion of the Ionian Sea in the tsunamigenic zones of Greece is strongly recommended
Tsunamis in the Greek Region: An Overview of Geological and Geomorphological Evidence
The Greek region is known as one of the most seismically and tectonically active areas and it has been struck by some devastating tsunamis, with the most prominent one being the 365 AD event. During the past decade significant research efforts have been made in search of geological and geomorphological evidence of palaeotsunamis along the Greek coasts, primarily through the examination of sediment corings (72% of studies) and secondarily through boulders (i.e., 18%). The published data show that some deposits have been correlated with well-known events such as 365 AD, 1303 AD, the Minoan Santorini Eruption and the 1956 Amorgos earthquake and tsunami, while coastal studies from western Greece have also reported up to five tsunami events, dating as far back as the 6th millennium BC. Although the Ionian Islands, Peloponnese and Crete has been significantly studied, in the Aegean region research efforts are still scarce. Recent events such as the 1956 earthquake and tsunami and the 2020 Samos earthquake and tsunami highlight the need for further studies in this region, to better assess the impact of past events and for improving our knowledge of tsunami history. As Greece is amongst the most seismically active regions globally and has suffered from devastating tsunamis in the past, the identification of tsunami prone areas is essential not only for the scientific community but also for public authorities to design appropriate mitigation measures and prevent tsunami losses in the future
Tsunamis in the Greek Region: An Overview of Geological and Geomorphological Evidence
The Greek region is known as one of the most seismically and tectonically active areas and it has been struck by some devastating tsunamis, with the most prominent one being the 365 AD event. During the past decade significant research efforts have been made in search of geological and geomorphological evidence of palaeotsunamis along the Greek coasts, primarily through the examination of sediment corings (72% of studies) and secondarily through boulders (i.e., 18%). The published data show that some deposits have been correlated with well-known events such as 365 AD, 1303 AD, the Minoan Santorini Eruption and the 1956 Amorgos earthquake and tsunami, while coastal studies from western Greece have also reported up to five tsunami events, dating as far back as the 6th millennium BC. Although the Ionian Islands, Peloponnese and Crete has been significantly studied, in the Aegean region research efforts are still scarce. Recent events such as the 1956 earthquake and tsunami and the 2020 Samos earthquake and tsunami highlight the need for further studies in this region, to better assess the impact of past events and for improving our knowledge of tsunami history. As Greece is amongst the most seismically active regions globally and has suffered from devastating tsunamis in the past, the identification of tsunami prone areas is essential not only for the scientific community but also for public authorities to design appropriate mitigation measures and prevent tsunami losses in the future
Tsunamis in the Greek Region: An Overview of Geological and Geomorphological Evidence
The Greek region is known as one of the most seismically and
tectonically active areas and it has been struck by some devastating
tsunamis, with the most prominent one being the 365 AD event. During the
past decade significant research efforts have been made in search of
geological and geomorphological evidence of palaeotsunamis along the
Greek coasts, primarily through the examination of sediment corings
(72% of studies) and secondarily through boulders (i.e., 18%). The
published data show that some deposits have been correlated with
well-known events such as 365 AD, 1303 AD, the Minoan Santorini Eruption
and the 1956 Amorgos earthquake and tsunami, while coastal studies from
western Greece have also reported up to five tsunami events, dating as
far back as the 6th millennium BC. Although the Ionian Islands,
Peloponnese and Crete has been significantly studied, in the Aegean
region research efforts are still scarce. Recent events such as the 1956
earthquake and tsunami and the 2020 Samos earthquake and tsunami
highlight the need for further studies in this region, to better assess
the impact of past events and for improving our knowledge of tsunami
history. As Greece is amongst the most seismically active regions
globally and has suffered from devastating tsunamis in the past, the
identification of tsunami prone areas is essential not only for the
scientific community but also for public authorities to design
appropriate mitigation measures and prevent tsunami losses in the
future
Palaeo-Tsunami Events on the Coasts of Cyprus
Cyprus has a long history of tsunami activity, as described in archaeological and geological records. Although the study area has experienced tsunamis in the past and constitutes an area threatened by this hazard both from the Cyprean arc and from the neighboring Hellenic arc, field research on tsunami evidence on the coastal zone of Cyprus still remains scarce. It is clear from the literature that large boulder accumulations are an important feature along the coasts of Cyprus, testifying to extreme events. A detailed field survey revealed that at various locations cited in the literature as hosting geomorphological evidence of past tsunamis, no such evidence was identified. It is likely that the high touristic activity that has been occurring on the coasts of Cyprus during the last 20 years may have affected tsunami indicators such as boulder accumulations. Tsunamis are unpredictable and infrequent but potentially large-impact natural disasters. The latest strong tsunami that caused damage to the Cypriot coast was centuries ago, when the population and economic growth and development at the Cypriot shoreline did not exist. Today, the coastal zone hosts a higher population as well as increasing touristic activity, highlighting the need for better preparedness, awareness raising and for tsunami-related risk reduction
Primary and Secondary Environmental Effects Triggered by the 30 October 2020, Mw=7.0, Samos (Eastern Aegean Sea, Greece) Earthquake Based on Post-Event Field Surveys and InSAR Analysis
On 30 October 2020, an Mw = 7.0 earthquake struck the eastern Aegean
Sea. It triggered earthquake environmental effects (EEEs) on Samos
Island detected by field surveys, relevant questionnaires, and
Interferometric Synthetic Aperture Radar (InSAR) analysis. The primary
EEEs detected in the field comprise coseismic uplift imprinted on rocky
coasts and port facilities around Samos and coseismic surface ruptures
in northern Samos. The secondary EEEs were mainly observed in northern
Samos and include slope failures, liquefaction, hydrological anomalies,
and ground cracks. With the contribution of the InSAR, subsidence was
detected and slope movements were also identified in inaccessible areas.
Moreover, the type of the surface deformation detected by InSAR is
qualitatively identical to field observations. As regards the EEE
distribution, effects were generated in all fault blocks. By applying
the Environmental Seismic Intensity (ESI-07) scale, the maximum
intensities were observed in northern Samos. Based on the results from
the applied methods, it is suggested that the northern and northwestern
parts of Samos constitute an almost 30-km-long coseismic deformation
zone characterized by extensive primary and secondary EEEs. The surface
projection of the causative offshore northern Samos fault points to this
zone, indicating a depth-surface connection and revealing a significant
role in the rupture propagation