Sürdürülebilir Kalkınma Amaçları
Yayınlar
- 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.
AtıfScopus7OpenAlex15
İncele - MakaleYalnız künye2023Scopus SJRQ1Modeling the form, distribution and paleoclimatic implications of former glaciers in the Teke Peninsula (Eastern Mediterranean, Turkey)
Keserci, Ferhat; Bayrakdar, Cihan; Çılğın, Zeynel; Evans, Ian S.
The Western Taurus Mountains on the Teke Peninsula, Southwestern Turkey, saw substantial glaciation in the late Quaternary period. Accurate reconstructions of former glacier extent in this relatively marginal area of glaciation are important for establishing the paleoclimate in the Eastern Mediterranean Basin. From west to east, the mountains of Sandıras, Karadağ, Akdağ (Kaş), and Beydağları preserve clear evidence of cirques and moraines, representing glacial valley land systems. This study used calculation tools for Glacier Reconstruction, (GlaRe) and Equilibrium Line Altitude (ELA), with glacier outlines based on the geomorphological evidence and Digital Elevation Models (DEMs), to determine the distribution and ELAs of former glaciers and to estimate paleotemperature and paleo-precipitation during the maximum ice extent. The results are analyzed at three scales: for each glacier, between glaciers and between mountain ranges. While the glaciation was at its peak, we estimate that glaciers covered a total area of 26.4 km2 (1.28 ± 0.08 km2 on Sandıras Mountain, 3.86 ± 0.23 km2 on Karadağ, 16.17 ± 0.970 km2 on Akdağ (Kaş), and 5.09 ± 0.30 km2 in Beydağları): the longest glacier was in Akdağ (Kaş) with a length of 5787 m. Average paleo-ELA (pELA) was calculated as 2077 m a.s.l in Sandıras, 2097 m a.s.l in Karadağ, 2565 m a.s.l in Akdağ (Kaş), and 2468 m a.s.l in Beydağları. Glacier modeling estimated that the maximum ice thickness in Akdağ was 240 m ± 14, and the average thickness 75 ± 4 m. Among these mountains, Karadağ had the lowest elevation to which glaciers descended (1760 ± 16 m a.s.l). Topographic analyses revealed that glaciers formed in the four mountains mostly in the North-facing localities with highest slope values of 18 to 30°. During the maximum glaciation period air temperature depression has been estimated as 8 to 9° Celsius; That required a precipitation increase of some 40 to 60 % compared to present, to produce the former glaciers mapped in the Teke Peninsula.
AtıfScopus10WoS9OpenAlex17
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