Sürdürülebilir Kalkınma Amaçları
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- MakaleAçık Erişim2024Scopus SJRQ1Morphometric characteristics of glacial cirques and former glaciers in the Geyik Mountains, Western Taurus, Türkiye
Çılğın, Zeynel; Evans, Ian S.; Keserci, Ferhat; Canpolat, Ergin; Bayrakdar, Cihan
Using the Glacier reconstruction (GlaRe) toolbox, reconstructions of former glaciers in the Geyik Mountains, part of the Taurus Mountain system in southern Türkiye, show that an area of 132.5 km2 was glaciated in the last major glaciation, which left clear terminal and hummocky moraines. Glaciers were 1.4 to 12 km long and those from 49 cirques merged to form a broad 75 km2 piedmont glacier in the Namaras Valley, up to 400 m thick. A thorough analysis of morphometry of the 98 Geyik cirques, using the revised Automated Cirque Metric Extraction version 2 (ACME2) toolbox, shows that they are relatively small, with limited widths: the median length/width ratio of 1.29 is unusually high. With size, length and width increase faster than depth, demonstrating strong static allometry. Maximum slope averages 59°, minimum 3.3° and axial 25°. A combination of low hypsometric integral, high axial profile closure and high axial height-length integral is proposed as a measure of cirque development. The main summits are on sharp ridges on cirque crests, showing that they have been lowered by glacial erosion (by cirque development). Glaciation was strongly asymmetric, with cirque vector mean aspect between northeast and north-northeast. This shows the dominance of solar radiation effects, with some modification from westerly winds. Glacier palaeo- Equilibrium Line Altitudes (pELAs) rise northeastwards and cirque floor minimum altitudes (CFAs) rise toward east-northeast, both showing the importance of moist air from the Mediterranean, 38–55 km to the southwest. pELA averages 2208 m above sea level (a.s.l.) (2277 m area-weighted); CFA averages 2234 m. CFA varies mainly with summit altitudes; where related palaeoglaciers are short CFA is somewhat below pELA, but for longer ones it is above. The most likely palaeoclimate to form these glaciers involves a precipitation increase of 53–72 % with a temperature fall of 8 °C compared with present-day. The cirques formed under similar or less severe conditions.
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İncele - MakaleAçık Erişim2020Scopus SJRQ1Chronology and Geomorphological Activity of the Akdag Rock Avalanche (SW Turkey)
Bayrakdar, Cihan; Gorum, Tolga; Çılğın, Zeynel; Vockenhuber, Christof; Ivy-Ochs, Susan; Akçar, Naki
Large rock-slope failures are among the primary geohazards in high mountain areas. These rock avalanches and rockslides constitute most of the world’s largest landslide deposits. This study focuses on the formation and geomorphological activity of the Akdag landslide complex located on the southern slope of Mount Akdag, SW Turkey. We employed detailed mapping in the field, spatial and morphometric analysis using GIS and remote sensing technologies, and surface exposure dating with cosmogenic 36Cl to reconstruct the chronology of the landslide complex. For the analysis of cosmogenic 36Cl, we collected 18 surface samples from calcareous boulders within the landslide deposit. Our field mapping shows that the Akdag rock avalanche is a large and active slope failure developed between carbonates and flysch. The rock-avalanche deposits cover an area of 9.8 km2 and together with the primary and secondary slope failures which form the landslide complex, cover an area of 15 km2. The Akdag rock avalanche is one of the largest (3 × 108 m3) known bedrock landslides in Turkey. Cosmogenic 36Cl exposure ages indicate that the main collapse occurred at 8.3 ± 1.4 ka (2σ), followed by secondary failures. We dated one of the latter to 1.1 ± 0.2 ka (2σ). Based on field evidence, we surmise that increased water discharge in the springs along the carbonate-flysch contact zone played a key role in the Early Holocene failure.
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İncele - MakaleYalnız künye2020Traces of late quaternary glaciations and paleoclimatic interpretation of Mount Akdağ (Alanya, 2451 m), Southwest Turkey
Bayrakdar, Cihan; Çılğın, Zeynel; Keserci, Ferhat
Mount Akdağ, located 25 km northeast of Alanya (2451 m above sea level a.s.l.), and largely made up of carbonates, is one of the mountains exposed to Late Quaternary glaciation in the Western Taurus Mountains. Although today, there are no modern glaciers, the traces of the Late Quaternary glaciers and rock glaciers are still fresh. In this study, geomorphological features related to the glaciations in Mount Akdağ, which were not previously reported in the literature, were first identified from satellite images, and then verified by field studies. The geomorphological development of Mount Akdağ during the Quaternary was explained by considering its climatic and karstic characteristics. For this purpose, spatial data obtained from field studies, unmanned aerial vehicles and meteorological stations were analysed using geographic information systems. Akdağ is directly open to humid air masses coming from the SW sector over the Mediterranean Sea, resulting in heavy orographic precipitation that encouraged the growth of glaciers. In addition, glacier reconstruction and pELA estimates have been made to contribute to the interpretation of glacial geomorphology. The pELA in Mount Akdağ was calculated with the AABR ratio of 1.69, and was found to be around 2030 m a.s.l. More than 15 cirques and a 6.5 km long glacial valley in Mount Akdağ indicate the presence of glaciers. Reconstruction of the paleoglaciers shows that the lowest altitude reached was 1410 m a.s.l. At their maximum extent glaciers covered an area of ~ 14 km2, with a volume of ~ 1 km3 and had an average thickness of 60 m with a maximum glacier thickness of ~ 200 m.
AtıfScopus19OpenAlex23İncele - MakaleAçık Erişim2017Pleistocene Glaciations in Karadag, Western Taurus Mountains, Turkey
Bayrakdar, Cihan; Çilgin, Zeynel; Saris, Faize
Karadag is one of the mountains subjected to the Pleistocene glaciations in the Teke Peninsula (Western Taurus) along with Beydaglari, Akdag, and Sandiras Mountains. Karadag, which reaches 2418 m summit at a 30 km straight distance from the northeast of Fethiye Bay, has many peaks over 2300 m. There are plenty of glacial researches and dating studies aim to reveal Pleistocene glaciation chronology of the mountains such as Sandiras and Akdag in the Teke Peninsula. On the other hand, glaciations in Beydaglari were mentioned superficially and in general terms. Lastly, there has not been known any glaciation phenomenon in Karadag, in other words there are not any studies concerning the glaciation on the mountain. However, Karadag has distinctive cirques and moraines on the slopes of high elevations near the peak. In this study, we identified glacial valleys, cirques developed in different sizes and aspects and lastly frontal and hummocky moraines in front of these cirques. They are descending to the elevation of 1800 m. With this study, a new glacial area was identified in Turkey and made a contribution to the glaciation inventory of Turkey. This study aims to reveal the geomorphological and climatological characteristics of this area with regard to tectonic, climatic and karstic characteristics during Pleistocene. Maps and relevant outputs were created and analyzed by geographic information systems using the spatial data obtained from the field studies, unmanned aerial vehicles and meteorological stations.
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