McHugh Cecilia M. G.

No Thumbnail Available
Last Name
McHugh
First Name
Cecilia M. G.
ORCID

Filters

2008 - 2009 1 2020 - 2023 1
1 1
2
Reset filters

Settings

Search Results

Now showing 1 - 2 of 2
  • Preprint
    The last reconnection of the Marmara Sea (Turkey) to the World Ocean : A paleoceanographic and paleoclimatic perspective
    ( 2008-07) McHugh, Cecilia M. G. ; Gurung, Damayanti ; Giosan, Liviu ; Ryan, William B. F. ; Mart, Yossi ; Sancar, Ummuhan ; Burckle, Lloyd H. ; Cagatay, M. Namik
    During the late glacial, marine isotope Stage 2, the Marmara Sea transformed into a brackish lake as global sea level fell below the sill in the Dardanelles Strait. A record of the basin’s reconnection to the global ocean is preserved in its sediments permitting the extraction of the paleoceanographic and paleoclimatic history of the region. The goal of this study is to develop a high-resolution record of the lacustrine to marine transition of Marmara Sea in order to reconstruct regional and global climatic events at 24 a millennial scale. For this purpose, we mapped the paleoshorelines of Marmara Sea along the northern, eastern, and southern shelves at Çekmece, Prince Islands, and Imrali, using data from multibeam bathymetry, high-resolution subbottom profiling (chirp) and ten sediment cores. Detailed sedimentologic, biostratigraphic (foraminifers, mollusk, diatoms), X-ray fluorescence geochemical scanning, and oxygen and carbon stable isotope analyses correlated to a calibrated radiocarbon chronology provided evidence for cold and dry conditions prior to 15 ka BP, warm conditions of the Bolling-Allerod from ~15 to 13 ka BP, a rapid marine incursion at 12 ka BP, still stand of Marmara Sea and sediment reworking of the paleoshorelines during the Younger Dryas at ~11.5 to 10.5 ka BP, and development of strong stratification and influx of nutrients as Black Sea waters spilled into Marmara Sea at 9.2 ka BP. Stable environmental conditions developed in Marmara Sea after 6.0 ka BP as sea-level reached its present shoreline and the basin floors filled with sediments achieving their present configuration.
  • Article
    Earthquake-enhanced dissolved carbon cycles in ultra-deep ocean sediments
    (Nature Research, 2023-09-11) Chu, Mengfan ; Bao, Rui ; Strasser, Michael ; Ikehara, Ken ; Everest, Jez ; Maeda, Lena ; Hochmuth, Katharina ; Xu, Li ; McNichol, Ann P. ; Bellanova, Piero ; Rasbury, E. Troy ; Kolling, Martin ; Riedinger, Natascha ; Johnson, Joel E. ; Luo, Min ; Marz, Christian ; Straub, Susanne ; Jitsuno, Kana ; Brunet, Morgane ; Cai, Zhirong ; Cattaneo, Antonio ; Hsiung, Kanhsi ; Ishizawa, Takashi ; Itaki, Takuya ; Kanamatsu, Toshiya ; Keep, Myra ; Kioka, Arata ; McHugh, Cecilia M. G. ; Micallef, Aaron ; Pandey, Dhananjai ; Proust, Jean Noel ; Satoguchi, Yasufumi ; Sawyer, Derek ; Seibert, Chloe ; Silver, Maxwell ; Virtasalo, Joonas ; Wang, Yonghong ; Wu, Ting-Wei ; Zellers, Sarah
    Hadal trenches are unique geological and ecological systems located along subduction zones. Earthquake-triggered turbidites act as efficient transport pathways of organic carbon (OC), yet remineralization and transformation of OC in these systems are not comprehensively understood. Here we measure concentrations and stable- and radiocarbon isotope signatures of dissolved organic and inorganic carbon (DOC, DIC) in the subsurface sediment interstitial water along the Japan Trench axis collected during the IODP Expedition 386. We find accumulation and aging of DOC and DIC in the subsurface sediments, which we interpret as enhanced production of labile dissolved carbon owing to earthquake-triggered turbidites, which supports intensive microbial methanogenesis in the trench sediments. The residual dissolved carbon accumulates in deep subsurface sediments and may continue to fuel the deep biosphere. Tectonic events can therefore enhance carbon accumulation and stimulate carbon transformation in plate convergent trench systems, which may accelerate carbon export into the subduction zones.