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Anatolian pLateau climatE and Tectonic hazards

Final Report Summary - ALERT (Anatolian pLateau climatE and Tectonic hazards)

ALErT: Anatolian pLateau climatE and Tectonic hazards ( ) aimed at providing new insights into the hazards and their forcing mechanisms in one of the most hazard-prone regions of Europe: the region encompassing the flanks and the interior sectors of the Anatolian Plateau. ALErT comprised 11 academic institutions and industry partners in the fields of Earth sciences, data mining, knowledge transfer, and risk communication. ALErT combined the resources and training structures of these partners to equip the next generation of geoscientists with the knowledge and skills they will need to meet the challenges of dealing with natural hazards in a rapidly changing natural environment, a region of pronounced seismicity and potential cascading effects, and in an area of important value concentrations and societal vulnerability.
ALErT’s research targets were focused on the tectonic and climatic boundary conditions that determine natural hazards in the densely populated flank regions and the tectonically active interiors of the Central Anatolian Plateau (CAP). The CAP constitutes semi-arid to arid high-elevation areas with subdued relief and internal drainage. The characteristics are contrasted by steep, rugged topography, often with high precipitation and pronounced surface-process rates along the flanks. We used this unique setting in the ALErT initiative to conduct a suite of 13 exemplary studies in order to decipher possible deep-seated processes driving plateau formation and to determine as to how these processes are reflected in the geological record, different landforms, and the degree of tectonic activity and deformation. Superposed climatically influenced processes, which may impact morphology and deformation styles, were also analyzed in parallel to evaluate their environmental impact over a variety of timescales. In addition, we focused on the visualization and knowledge-transfer aspects as well as data management and information transfer trough communication to stakeholders.
After 4 years of run-time (2013-2017), we conclude that the principal aim of the initiative – “to establish a research-based virtual campus, designed to provide excellent training of geoscientists through cutting-edge research topics and the transfer of knowledge” – was accomplished and the following scientific results have been achieved:
(1) Regarding the tectonic impacts on surface processes and their deep-rooted sources, we found evidence, that Holocene faulting and paleo-earthquakes with tsunamigenic deposits, that affected the Mediterranean coast off southern Turkey, clearly document the recency of tectonism and inherent hazards of seismogenic activity along the Turkish Mediterranean coast. These phenomena help us to better understand the mechanisms responsible for the uplift of the CAP’s southern margin on geological timescales. Our results will have to be taken into account for future seismic and tsunami-risk assessment, particularly in areas where strategic infrastructure has been planned (e.g. Akkuyu Nuclear Power Plant). Moreover, investigated marine landscapes and tectonic features along the southern coast of Crete and Kythira islands (Greece) support the notion that marine terraces, river terraces, and pediments are sensitive recorders of tectonism; combined with instrumental records of geodesy and seismicity the study of uplifted and deformed terrace systems may thus provide important information about tectonic activity in the past and potential trends in future seismogenic deformation.
We also studied the long-term exhumation processes at the northern margin of the CAP using thermochronology. Located along the southern margin of the Eurasian plate, the Central Pontides of N Turkey represent a mobile orogenic belt that experienced several phases of exhumation. Our investigations in this section document the punctuated nature of fault-related exhumation and the role of inverted normal faults in controlling the exhumation patterns at ~60 to 45 and ~40 to 25 Ma. Furthermore, the thermochronologic data suggest a diachronous timing of the Arabia-Eurasia collision, which started at ~40 Ma in front of the Arabian indenter and propagated south-eastward between 35 and 27 Ma, and the occurrence of late Miocene to Quaternary exhumation shortly after the occurrence of slab break-off and the onset of the westward motion of Anatolia. In a further attempt, where analyzed seismic reflection data from the offshore areas to the N and S of the Anatolian Plateau, we could show that while the thermal anomaly leading to passive margin formation in the South Atlantic should be equilibrated, the thermal disturbance in the North Atlantic obviously still causes thermal effects at the present-day. Different geological and geophysical data of the Marmara region helped to build a new 3D lithospheric-scale structural model, which we additionally constrained by 3D gravity modeling. Our findings reveal that characteristics of the lithosphere ultimately determine the thermal field for the two settings. The fact that the geothermal gradient is nonlinear and varies across structural basin settings has important implications for methods of thermal history reconstruction and exhumation processes.

In terms of (2) climatic impacts on surface processes and their interaction with tectonics, ALErT conducted studies at the northern margin of the CAP in the Pontide mountains, as well as in the offshore area of the Kızılırmak River delta, from the Turkish coast of the Black Sea to the Archangelsky Ridge. Our combined analysis of elevation transects, geomorphic mapping and OSL dating of fluvial terraces, reveal that fluvial incision is driven by tectonic uplift and deformation. We have shown that although the northern margin of the CAP has inherited much of its morphology from the Eocene, the mechanisms driving uplift since the Late Miocene have persisted until the present and are expressed by >1,500 m of bedrock incision into the orogenic wedge. Periods of low, <0.1 mm/yr uplift are surprising this close to the North Anatolian Fault. However, our results suggest that motion of the Karabük Fault may introduce episodes of significantly higher uplift/erosion rates and activity of the fault may have been greater earlier in the Quaternary. Also, the studies document protracted tectonic activity in the Black Sea basin during the Quaternary. However, this tectonic activity is kinematically very different from the Pontide wedge system, which advances northward via thrust faults exposed in the Sinop region that are younging northward. Immediately north of these contractional faults, however, we observed active normal faulting associated with graben formation, which suggests a decoupling of tectonic processes in close vicinity to each other in this collisional environment. Additional pollen and stable-isotope paleo-environmental studies on sediments of the Sinop region, Kastamonu Province (Alçıcılar) and the Kırşehir Mountains (northwest Tosya, Ilgaz, Nalbantoğlu, and Çifter) provides an important cross validation for a model suggesting paleo-environmental impacts of tectonic uplift of the CAP and the onset of new climate patterns in this region.
Since it was an important aspect of the ALErT initiative, the tasks of (3) data compilation, data visualization, communication, and the extraction and presentation of information for a non-academic audience were focused in customized work packages: We developed concrete measures in the field of science communication by providing information to practitioners and decision makers. Our industry partners Oracle, BSF SwissPhoto, and Active Earth were mainly responsible for these topics. Jointly with ITU and UP, these partners conducted short courses related to (a) data management and visualization, and (b) communication aspects. Additionally, we invited Prof. R. Bilham of CIRES, Boulder, and D. Sarewitz from ASU, Arizona, to share their ideas on scientific knowledge transfer and the lack of (geo-) governance structures in many countries predisposed to the impacts of natural hazards. In ALErT, we exemplarily conducted a study to analyze the severity of flooding in comparison to other natural hazards in Turkey and to analyze the flood patterns by providing an overview of the temporal and spatial distribution of flood losses. Based on our investigations of the Turkey Disaster Database (TABB; 1960-2014), flood events have high destructive effects in terms of economic and the societal impacts after earthquakes; the northern and southern plateau, i.e. the Black Sea and Mediterranean regions, respectively, record the highest event frequency, the highest economic and human losses due to flooding. In light of our findings we suggest that most of the loss parameters in TABB (e.g. number of damaged buildings, total missing or displaced, total damage) should be updated, because they are incomplete. During the process of computing disaster data, attention should thus be paid to the accuracy of data and data quality controls. Furthermore, the TABB database should be classified according to a globally accepted disaster classification system for providing a unified terminology for operating loss databases. This is also important regarding standardization, methodology and definitions that should be explained clearly in a uniform manner.
In parallel, we tested different remote sensing technologies to detect landforms diagnostic of natural-hazard related processes. Our study constitutes a methodological approach, which has applications for steep terrain in mountain belts worldwide. Our studies demonstrate that remote-sensing techniques may play a crucial role when analyzing surface parameters of tectonically-active regions, such as the CAP or the Tibetan Plateau. ALErT clearly demonstrated the potential of the application of object-based image analysis for the automatic detection of morphology parameters. Furthermore, our results show that surface roughness is a promising metric for detecting different landforms in diverse environments, and that OBIA assists significantly in detecting parts of lakes and snow avalanches that may be misclassified if traditional methods, such as thresh-holding of spectral properties of data and their derivatives are used. Also, our newly developed Semantic Spatial Reasoning conceptual framework approaches (together with our industry partner ORACLE), show that geo-data analytical tools might be useful in different application areas, such as GIS, cognitive vision, computer-aided design, and data integration. Since declarative rules are the first-class citizens of the framework, it allows generating new, spatially-enabled knowledge from existing knowledge, such as generating implicit consequences of some spatial events like earthquakes and industrial disasters.
Finally, under the leadership of University of Plymouth and the film-making company Active Earth, movie-making and storytelling approaches were applied to the problem of seismic risk communication in the Istanbul metropolitan area. ALErT was able to demonstrate that storytelling approaches, and GIS-based story maps, help support public interpretation of natural hazards and risks. We successfully tested the use of film as a medium for participatory dialogue in the context of earthquake risk within Istanbul’s earthquake-prone neighborhoods. ALErT also examined the practical and ethical responsibilities of geoscientists in this emergent participatory approach to community-centered communication. From our project, it clearly emerged that the combination of GIS maps, web-based geo-information tools and new approaches in hazard communication are crucial for a more efficient knowledge transfer in future.
In conclusion, the results of the ALErT initiative show the close interaction between active tectonic and climatic forcings, a high degree of climatic variability, and pronounced geomorphic gradients along the margins of the CAP –taken together, these mechanisms are the main reason for the vulnerability that local communities are subjected to. Our studies show that - with respect to long timescales (geological timescales, i.e. 106 years) - intermontane basins at the northern plateau margins are key for our understanding when the plateau margin became an efficient orographic barrier that blocked moisture and helped establish arid conditions in the plateau interior (pollen analysis and XRD-based mineral species identification; thermochronology). While it is clear now that the basins along the northern plateau margin record similar depositional environments during their successive incorporation into the plateau realm, there is still an ongoing debate with respect to the propagation of plateau uplift and associated deformation toward the Black Sea region. On much shorter timescales, involving decades to several millennia, ALErT strived to collect and interpret data on seismicity, mass movements, as well as present-day and paleo-erosion rates. We emphasize that before paleo-erosion processes are quantified, modern erosion rates need to be determined to efficiently assess variations in climate, hillslope angle, and peak-ground acceleration (i.e. proximity to the North Anatolian Fault, NAF).
In addition to our geological topics, we emphasized knowledge transfer in our study and demonstrated that based on the large number of different data sets related to geological and hydro-meteorological forcing factors, the recognition, retrieval and implementation of different data sources in new software applications, the presentation of knowledge in web-based GIS portals, are important factors to be taken into account. In ALErT, excellent research was conducted, which resulted in peer-reviewed publications, outstanding contributions to international conferences and workshops, and innovative online-accessible media productions; this information was used to translate scientific results into accessible knowledge for stakeholders. Importantly, through several training measures the ESRs were equipped with a portfolio of methodological knowledge beyond the state-of-the-art that provided an analytical platform and expertise for the individual research topics. All of our ESRs have entered – or are ready to enter – new career steps: some of them in high-class academic environments, others in industry. We are therefore confident that ALErT is an excellent example of how to combine the excellence in research and research-based teaching of several European partners to train young professionals.