Rapid Climate Changes in the Westernmost Mediterranean (Alboran Sea) Over the Last 35 kyr: New Insights From Four Lipid Paleothermometers (UK'37, TEXH86, RI-OH', and LDI)

• Published in: Paleoceanography and Paleoclimatology
• Main Authors: Morcillo-Montalbá, Laura, Rodrigo Gámiz, Marta, Martínez-Ruíz, Francisca, Ortega-Huertas, M., Schouten, Stefan, Sinninghe Damsté, J.S.
• Other Authors: European Commission, Ministerio de Ciencia e Innovación (España), Netherlands Earth System Science Centre, Universidad de Granada, Junta de Andalucía
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: Wiley-VCH 2021
• Subjects: Dansgaard-Oeschger cycles; Heinrich events; lipid biomarkers; organic paleothermometers; paleoclimate reconstruction; westernmost Mediterranean; Planktonic foraminifera
• Online Access: http://hdl.handle.net/10261/276429; https://doi.org/10.1029/2020PA004171; https://doi.org/10.13039/501100011011; https://doi.org/10.13039/501100004837; https://doi.org/10.13039/501100006393; https://doi.org/10.13039/501100000780

The westernmost Mediterranean is one of the most sensitive areas to global climate change and high sedimentation rates allow recording high frequency variability. We present a high-resolution paleotemperature reconstruction over the last 35 kyr using, for the first time, four independent organic sea surface temperature (SST) proxies (U, TEX, RI-OH' and LDI) based on alkenones, (hydroxy) isoprenoid GDGTs, and long-chain diols. We also generated a δO of planktonic foraminifera G. bulloides record together with records of bulk parameters (total organic carbon content, δC) and the accumulation rates of different biomarkers to provide insights into terrestrial input and primary producers. All derived-SST records showed similar trends over the last 35 kyr, revealing abrupt temperature variations during the last seven Dansgaard-Oeschger (D/O) cycles, the three Heinrich (H) events, the Last Glacial Maximum, and the Younger Dryas. H3 is recognized as the coldest event, while H1 was recorded by all SST proxies as the most abrupt one. In general, TEX-, RI-OH'- and LDI-SST estimates were lower than those obtained from U. The LDI paleothermometer recorded the largest range of absolute SSTs over the whole period (ca. 20°C) followed by RI-OH' (ca. 16°C). TEX, RI-OH' and LDI proxies reflected sudden SST changes during the D/O 6 and 5 particularly well. Low BIT values and the abundance of C 1,15-diol in range with typical marine values indicated only minor input of continental organic matter. Accumulation rates of different lipid biomarkers were generally modulated by D/O cycles, suggesting enhanced productivity during D/O interstadials and the Bölling-Alleröd period. This study was supported by Grant PID2019‐104624RB‐I00 funded by MCIN/AEI/ 10.13039/501100011033, Grants FEDER/Junta de Andalucía‐Consejería de Economía y Conocimiento P18‐RT‐3804 and P18‐RT‐ 4074, and Research Group RNM‐179 (Junta de Andalucía). The authors also thank the Unidad Científica de Excelencia UCE‐PP2016‐05 (University of Granada). This study also ...