Accurate relocation of seismicity along the North Aegean Trough and its relation to active tectonics

2017 ◽  
Vol 717 ◽  
pp. 372-382 ◽  
Author(s):  
K.I. Konstantinou
Keyword(s):  
Active Tectonics ◽  
The North ◽  
North Aegean

scholarly journals Morphotectonic Analysis along the Northern Margin of Samos Island, Related to the Seismic Activity of October 2020, Aegean Sea, Greece

Geosciences ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 102
Author(s):  
Paraskevi Nomikou ◽  
Dimitris Evangelidis ◽  
Dimitrios Papanikolaou ◽  
Danai Lampridou ◽  
Dimitris Litsas ◽  
...  
Keyword(s):  
Fault Zone ◽  
Seismic Activity ◽  
Volcanic Rocks ◽  
Active Tectonics ◽  
Normal Fault ◽  
Aegean Sea ◽  
Northern Margin ◽  
The North ◽  
Eastern Aegean ◽  
Half Graben

On 30 October 2020, a strong earthquake of magnitude 7.0 occurred north of Samos Island at the Eastern Aegean Sea, whose earthquake mechanism corresponds to an E-W normal fault dipping to the north. During the aftershock period in December 2020, a hydrographic survey off the northern coastal margin of Samos Island was conducted onboard R/V NAFTILOS. The result was a detailed bathymetric map with 15 m grid interval and 50 m isobaths and a morphological slope map. The morphotectonic analysis showed the E-W fault zone running along the coastal zone with 30–50° of slope, forming a half-graben structure. Numerous landslides and canyons trending N-S, transversal to the main direction of the Samos coastline, are observed between 600 and 100 m water depth. The ENE-WSW oriented western Samos coastline forms the SE margin of the neighboring deeper Ikaria Basin. A hummocky relief was detected at the eastern margin of Samos Basin probably representing volcanic rocks. The active tectonics characterized by N-S extension is very different from the Neogene tectonics of Samos Island characterized by NE-SW compression. The mainshock and most of the aftershocks of the October 2020 seismic activity occur on the prolongation of the north dipping E-W fault zone at about 12 km depth.

Geodetic analysis of the tectonic crustal deformation pattern in the North Aegean Sea, Greece

2021 ◽  
Author(s):  
Ilias Lazos ◽  
Sotirios Sboras ◽  
Christos Pikridas ◽  
Spyros Pavlides ◽  
Alexandros Chatzipetros
Keyword(s):  
Crustal Deformation ◽  
Aegean Sea ◽  
Deformation Pattern ◽  
The North ◽  
North Aegean ◽  
North Aegean Sea

scholarly journals A Prospective Study for the Mitigation of the Climate Change Effects: The Case of the North Aegean Region of Greece

2020 ◽  
Vol 12 (24) ◽  
pp. 10420
Author(s):  
Ioannis Chatziioannou ◽  
Efthimios Bakogiannis ◽  
Charalampos Kyriakidis ◽  
Luis Alvarez-Icaza
Keyword(s):  
Climate Change ◽  
Prospective Study ◽  
Adaptation To Climate Change ◽  
Water Shortages ◽  
Sea Levels ◽  
Aegean Region ◽  
Climate Change Effects ◽  
The North ◽  
North Aegean ◽  
A Prospective Study

One of the biggest challenges of our time is climate change. Every day, at different places of the world, the planet sends alarming messages about the enormous transformations it is experiencing due to human-based activities. The latter are responsible for changing weather patterns that threaten food production, energy production and energy consumption, the desertification of land, the displacement of people and animals because of food and water shortages due to the reductions in rainfall, natural disasters and rising sea levels. The effects of climate change affect us all, and if drastic measures are not considered in a timely manner, it will be more difficult and costly to adapt to the aforementioned effects in the future. Considering this context, the aim of this work is to implement a prospective study/structural analysis to the identified sectors of a regional plan of adaptation to climate change so as to promote the resilience of the region against the negative phenomena generated by the climate crisis. This was achieved in two steps: first, we identified the relationships between the strategic sectors of the plan and organized them in order of importance. Second, we assessed the effectiveness of several public policies oriented towards a city’s resilience according to their impact upon the strategic sectors of the plan and the co-benefits generated by their implementation for society. The results highlight that the most essential sectors for the mitigation of climate change are flood risk management, built environment, forest ecosystem management, human health, tourism and rise in sea level. As a consequence, the most important measures for the resilience of the North Aegean Region against climate change are the ones related to the preparation of strategic master plans for flood protection projects.

scholarly journals Active Tectonics of the North Chilean Marine Forearc and Adjacent Oceanic Nazca Plate

Tectonics ◽  
2018 ◽  
Vol 37 (11) ◽  
pp. 4194-4211 ◽  
Author(s):  
Jacob Geersen ◽  
César R. Ranero ◽  
Ingo Klaucke ◽  
Jan H. Behrmann ◽  
Heidrun Kopp ◽  
...  
Keyword(s):  
Active Tectonics ◽  
Nazca Plate ◽  
The North

scholarly journals Hydrology and circulation in the North Aegean (eastern Mediterranean) throughout 1997 and 1998

2002 ◽  
Vol 3 (1) ◽  
pp. 5 ◽  
Author(s):  
V. ZERVAKIS ◽  
D. GEORGOPOULOS
Keyword(s):  
Surface Layer ◽  
Black Sea ◽  
Sea Water ◽  
Saline Water ◽  
Eastern Mediterranean ◽  
Late Summer ◽  
Cyclonic Circulation ◽  
The Black Sea ◽  
The North ◽  
North Aegean

The combination of two research projects offered us the opportunity to perform a comprehensive study of the seasonal evolution of the hydrological structure and the circulation of the North Aegean Sea, at the northern extremes of the eastern Mediterranean. The combination of brackish water inflow from the Dardanelles and the sea-bottom relief dictate the significant differences between the North and South Aegean water columns. The relatively warm and highly saline South Aegean waters enter the North Aegean through the dominant cyclonic circulation of the basin. In the North Aegean, three layers of distinct water masses of very different properties are observed: The 20-50 m thick surface layer is occupied mainly by Black Sea Water, modified on its way through the Bosphorus, the Sea of Marmara and the Dardanelles. Below the surface layer there is warm and highly saline water originating in the South Aegean and the Levantine, extending down to 350-400 m depth. Below this layer, the deeper-than-400 m basins of the North Aegean contain locally formed, very dense water with different θ /S characteristics at each subbasin. The circulation is characterised by a series of permanent, semi-permanent and transient mesoscale features, overlaid on the general slow cyclonic circulation of the Aegean. The mesoscale activity, while not necessarily important in enhancing isopycnal mixing in the region, in combination with the very high stratification of the upper layers, however, increases the residence time of the water of the upper layers in the general area of the North Aegean. As a result, water having out-flowed from the Black Sea in the winter, forms a separate distinct layer in the region in spring (lying between “younger” BSW and the Levantine origin water), and is still traceable in the water column in late summer.

scholarly journals THE 2014 MW 6.9 NORTH AEGEAN TROUGH (NAT) EARTHQUAKE: SEISMOLOGICAL AND GEODETIC EVIDENCE

2017 ◽  
Vol 50 (3) ◽  
pp. 1583
Author(s):  
V. Saltogianni ◽  
M. Gianniou ◽  
T. Taymaz ◽  
S. Yolsal-Çevikbilen ◽  
S. Stiros
Keyword(s):  
Broad Band ◽  
Strike Slip ◽  
Fault Geometry ◽  
Coseismic Slip ◽  
The North ◽  
Finite Fault Inversion ◽  
Seismological Data ◽  
Finite Fault ◽  
Slip History ◽  
North Aegean

A strong earthquake (Mw 6.9) on 24 May 2014 ruptured the North Aegean Trough (NAT) in Greece, west of the North Anatolian Fault Zone (NAFZ). In order to provide unbiased constrains of the rupture process and fault geometry of the earthquake, seismological and geodetic data were analyzed independently. First, based on teleseismic long-period P- and SH- waveforms a point-source solution yielded dominantly right-lateral strike-slip faulting mechanism. Furthermore, finite fault inversion of broad-band data revealed the slip history of the earthquake. Second, GPS slip vectors derived from 11 permanent GPS stations uniformly distributed around the meizoseismal area of the earthquake indicated significant horizontal coseismic slip. Inversion of GPS-derived displacements on the basis of Okada model and using the new TOPological INVersion (TOPINV) algorithm permitted to model a vertical strike slip fault, consistent with that derived from seismological data. Obtained results are consistent with the NAT structure and constrain well the fault geometry and the dynamics of the 2014 earthquake. The latter seems to fill a gap in seismicity along the NAT in the last 50 years, but seems not to have a direct relationship with the sequence of recent faulting farther east, along the NAFZ.

scholarly journals SEDIMENTOLOGICAL AND GEOCHEMICAL ANALYSIS OF MIOCENE DEPOSITS IN MOSCHOPOTAMOS AREA, IN THE WESTERN PART OF AXIOS-THERMAIKOS BASIN, NW GREECE

2017 ◽  
Vol 50 (1) ◽  
pp. 374
Author(s):  
V. Savva ◽  
P. Tserolas ◽  
A. Maravelis ◽  
N. Bourli ◽  
A. Zelilidis
Keyword(s):  
Organic Matter ◽  
Organic Content ◽  
Sieve Analysis ◽  
Organic Carbon Content ◽  
Geochemical Analysis ◽  
Aegean Area ◽  
Sedimentary Characteristics ◽  
The North ◽  
Caco3 Content ◽  
North Aegean

A total of 27 samples of the Moschopotamos area lignite-bearing strata were studied in regard of their geochemical and sedimentary characteristics. Organic content and calcium carbonate evaluation, sieve analysis and micropaleontological observations were used and combined to investigate the paleoenvironment and the depositional conditions of the study area. TOC analysis showed that organic matter values range from 0.07% up to 13.42% with an average of ~3.26 %. The high average of organic carbon content indicates a promising basis for the sediments’ source rock potential, inquiring further and thorough examination. CaCO3 measurements present a range between 4% and 23%. A comparison between TOC-CaCO3 content throughout the stratigraphic column presented certain synchronous and inverse trends, due to alterations of the depositional conditions. This study provides new insights for the understanding of the broader Axios-Thermaikos basin, and depositional conditions in the North Aegean area.

scholarly journals A three dimensional, full life cycle, anchovy and sardine model for the North Aegean Sea (Eastern Mediterranean): Validation, sensitivity and climatic scenario simulations

2021 ◽  
Vol 22 (3) ◽  
pp. 653
Author(s):  
ATHANASIOS GKANASOS ◽  
EUDOXIA SCHISMENOU ◽  
KOSTAS TSIARAS ◽  
STYLIANOS SOMARAKIS ◽  
MARIANNA GIANNOULAKI ◽  
...  
Keyword(s):  
Temperature Increase ◽  
Eastern Mediterranean ◽  
Larval Growth ◽  
Somatic Growth ◽  
Aegean Sea ◽  
Fish Growth ◽  
Prey Concentration ◽  
The North ◽  
North Aegean ◽  
North Aegean Sea

We present the development of a 3D full-lifecycle, individual-based model (IBM) for anchovy and sardine, online coupled to an existing hydrodynamic/biogeochemical low-trophic level (LTL) model for the North Aegean Sea. It was built upon an existing 1D model for the same species and area, with the addition of a horizontal movement scheme. In the model, both species evolve from the embryonic stage (egg+yolk sac larva) to the larval, juvenile, and adult stages. Somatic growth is simulated with the use of a “Wisconsin” type bioenergetics model and fish populations with an adaptation of the ‘super individuals’ (SI) approach. For the reference simulation and model calibration, in terms of fish growth and population biomass, the 2000-2010 period was selected. Interannual biomass variability of anchovy was successfully represented by the model, while the simulated biomass of sardine exhibited low variability and did not satisfactorily reproduce the observed interannual variability from acoustic surveys. The spatial distribution of both species’ biomass was in relatively good agreement with field data. Additional single-species simulations revealed that species compete for food resources. Temperature sensitivity experiments showed that both species reacted negatively to a temperature increase. Anchovy, in particular, was more affected since its spawning and larval growth periods largely overlap with the period of maximum yearly temperature and low prey concentration. Finally, simulation experiments using IPCC climatic scenarios showed that the predicted temperature increase and zooplankton concentration decrease in the future will negatively affect anchovy, resulting in sardine prevalence.

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