@article{WarringtonBeaumontHorikoshietal.2019, author = {Warrington, Nicole and Beaumont, Robin and Horikoshi, Momoko and Day, Felix R. and Helgeland, {\O}yvind and Laurin, Charles and Bacelis, Jonas and Peng, Shouneng and Hao, Ke and Feenstra, Bjarke and Wood, Andrew R. and Mahajan, Anubha and Tyrrell, Jessica and Robertson, Neil R. and Rayner, N. William and Qiao, Zhen and Moen, Gunn-Helen and Vaudel, Marc and Marsit, Carmen and Chen, Jia and Nodzenski, Michael and Schnurr, Theresia M. and Zafarmand, Mohammad Hadi and Bradfield, Jonathan P. and Grarup, Niels and Kooijman, Marjolein N. and Li-Gao, Ruifang and Geller, Frank and Ahluwalia, Tarunveer Singh and Paternoster, Lavinia and Rueedi, Rico and Huikari, Ville and Hottenga, Jouke-Jan and Lyytik{\"a}inen, Leo-Pekka and Cavadino, Alana and Metrustry, Sarah and Cousminer, Diana L. and Wu, Ying and Thiering, Elisabeth Paula and Wang, Carol A. and Have, Christian Theil and Vilor-Tejedor, Natalia and Joshi, Peter K. and Painter, Jodie N. and Ntalla, Ioanna and Myhre, Ronny and Pitk{\"a}nen, Niina and van Leeuwen, Elisabeth M. and Joro, Raimo and Lagou, Vasiliki and Richmond, Rebecca C. and Espinosa, Ana and Barton, Sheila J. and Inskip, Hazel M. and Holloway, John W. and Santa-Marina, Loreto and Estivill, Xavier and Ang, Wei and Marsh, Julie A. and Reichetzeder, Christoph and Marullo, Letizia and Hocher, Berthold and Lunetta, Kathryn L. and Murabito, Joanne M. and Relton, Caroline L. and Kogevinas, Manolis and Chatzi, Leda and Allard, Catherine and Bouchard, Luigi and Hivert, Marie-France and Zhang, Ge and Muglia, Louis J. and Heikkinen, Jani and Morgen, Camilla S. and van Kampen, Antoine H. C. and van Schaik, Barbera D. C. and Mentch, Frank D. and Langenberg, Claudia and Scott, Robert A. and Zhao, Jing Hua and Hemani, Gibran and Ring, Susan M. and Bennett, Amanda J. and Gaulton, Kyle J. and Fernandez-Tajes, Juan and van Zuydam, Natalie R. and Medina-Gomez, Carolina and de Haan, Hugoline G. and Rosendaal, Frits R. and Kutalik, Zolt{\´a}n and Marques-Vidal, Pedro and Das, Shikta and Willemsen, Gonneke and Mbarek, Hamdi and M{\"u}ller-Nurasyid, Martina and Standl, Marie and Appel, Emil V. R. and Fonvig, Cilius Esmann and Trier, Caecilie and van Beijsterveldt, Catharina E. M. and Murcia, Mario and Bustamante, Mariona and Bon{\`a}s-Guarch, S{\´i}lvia and Hougaard, David M. and Mercader, Josep M. and Linneberg, Allan and Schraut, Katharina E. and Lind, Penelope A. and Medland, Sarah Elizabeth and Shields, Beverley M. and Knight, Bridget A. and Chai, Jin-Fang and Panoutsopoulou, Kalliope and Bartels, Meike and S{\´a}nchez, Friman and Stokholm, Jakob and Torrents, David and Vinding, Rebecca K. and Willems, Sara M. and Atalay, Mustafa and Chawes, Bo L. and Kovacs, Peter and Prokopenko, Inga and Tuke, Marcus A. and Yaghootkar, Hanieh and Ruth, Katherine S. and Jones, Samuel E. and Loh, Po-Ru and Murray, Anna and Weedon, Michael N. and T{\"o}njes, Anke and Stumvoll, Michael and Michaelsen, Kim Fleischer and Eloranta, Aino-Maija and Lakka, Timo A. and van Duijn, Cornelia M. and Kiess, Wieland and Koerner, Antje and Niinikoski, Harri and Pahkala, Katja and Raitakari, Olli T. and Jacobsson, Bo and Zeggini, Eleftheria and Dedoussis, George V. and Teo, Yik-Ying and Saw, Seang-Mei and Montgomery, Grant W. and Campbell, Harry and Wilson, James F. and Vrijkotte, Tanja G. M. and Vrijheid, Martine and de Geus, Eco J. C. N. and Hayes, M. Geoffrey and Kadarmideen, Haja N. and Holm, Jens-Christian and Beilin, Lawrence J. and Pennell, Craig E. and Heinrich, Joachim and Adair, Linda S. and Borja, Judith B. and Mohlke, Karen L. and Eriksson, Johan G. and Widen, Elisabeth E. and Hattersley, Andrew T. and Spector, Tim D. and Kaehoenen, Mika and Viikari, Jorma S. and Lehtimaeki, Terho and Boomsma, Dorret I. and Sebert, Sylvain and Vollenweider, Peter and Sorensen, Thorkild I. A. and Bisgaard, Hans and Bonnelykke, Klaus and Murray, Jeffrey C. and Melbye, Mads and Nohr, Ellen A. and Mook-Kanamori, Dennis O. and Rivadeneira, Fernando and Hofman, Albert and Felix, Janine F. and Jaddoe, Vincent W. V. and Hansen, Torben and Pisinger, Charlotta and Vaag, Allan A. and Pedersen, Oluf and Uitterlinden, Andre G. and Jarvelin, Marjo-Riitta and Power, Christine and Hypponen, Elina and Scholtens, Denise M. and Lowe, William L. and Smith, George Davey and Timpson, Nicholas J. and Morris, Andrew P. and Wareham, Nicholas J. and Hakonarson, Hakon and Grant, Struan F. A. and Frayling, Timothy M. and Lawlor, Debbie A. and Njolstad, Pal R. and Johansson, Stefan and Ong, Ken K. and McCarthy, Mark I. and Perry, John R. B. and Evans, David M. and Freathy, Rachel M.}, title = {Maternal and fetal genetic effects on birth weight and their relevance to cardio-metabolic risk factors}, series = {Nature genetics}, volume = {51}, journal = {Nature genetics}, number = {5}, publisher = {Nature Publ. Group}, address = {New York}, organization = {EGG Consortium}, issn = {1061-4036}, pages = {804 -- +}, year = {2019}, abstract = {Birth weight variation is influenced by fetal and maternal genetic and non-genetic factors, and has been reproducibly associated with future cardio-metabolic health outcomes. In expanded genome-wide association analyses of own birth weight (n = 321,223) and offspring birth weight (n = 230,069 mothers), we identified 190 independent association signals (129 of which are novel). We used structural equation modeling to decompose the contributions of direct fetal and indirect maternal genetic effects, then applied Mendelian randomization to illuminate causal pathways. For example, both indirect maternal and direct fetal genetic effects drive the observational relationship between lower birth weight and higher later blood pressure: maternal blood pressure-raising alleles reduce offspring birth weight, but only direct fetal effects of these alleles, once inherited, increase later offspring blood pressure. Using maternal birth weight-lowering genotypes to proxy for an adverse intrauterine environment provided no evidence that it causally raises offspring blood pressure, indicating that the inverse birth weight-blood pressure association is attributable to genetic effects, and not to intrauterine programming.}, language = {en} } @article{LuChengWangetal.2017, author = {Lu, Honghua and Cheng, Lu and Wang, Zhen and Zhang, Tianqi and Lu, Yanwu and Zhao, Junxiang and Li, Youli and Zheng, Xiangmin}, title = {Latest Quaternary rapid river incision across an inactive fold in the northern Chinese Tian Shan foreland}, series = {Quaternary science reviews : the international multidisciplinary research and review journal}, volume = {179}, journal = {Quaternary science reviews : the international multidisciplinary research and review journal}, publisher = {Elsevier}, address = {Oxford}, issn = {0277-3791}, doi = {10.1016/j.quascirev.2017.10.017}, pages = {167 -- 181}, year = {2017}, abstract = {This work focuses on the incision process over the Tuostai anticline, a fold of the proximal structure Belt I in the northern Chinese Tian Shan foreland, where the Sikeshu River has incised deeply into the alluvial gravels and the fold's underlying bedrock strata. Field investigation and geomorphic mapping define five terraces of the Sikeshu River (designated as T1 to T5 from oldest to youngest) preserved within the Tuostai anticline. 10Be surface exposure dating and optically stimulated luminescence dating constrain stabilization of the highest three terrace surfaces at about 80 ka (T1), 16 ka (T2), and 15 ka (T3), respectively. Around 16 ka, the calculated river incision rates significantly increase from <2 mm/yr to >6 mm/yr. Undeformed longitudinal profiles of terraces T2, T3 and T4 over the Tuostai anticline suggest that this structure may have been tectonically inactive since stabilization of these three terraces. We thus think that the observed rapid river incision over the Tuostai anticline has not been largely forced by tectonic uplift. Instead, the progressively warmer and wetter palaeoclimatic condition within the Tian Shan range and its surrounding area during the period of ∼20-10 ka may have enhanced river incision across the Tuostai anticline. A reduced sediment/water ratio might have lowered the gradient of the Sikeshu River.}, language = {en} } @phdthesis{Li2023, author = {Li, Zhen}, title = {Formation of Sub-Permafrost Methane Hydrate Reproduced by Numerical Modeling}, doi = {10.25932/publishup-60330}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-603302}, school = {Universit{\"a}t Potsdam}, pages = {XII, 109}, year = {2023}, abstract = {Natural gas hydrates are ice-like crystalline compounds containing water cavities that trap natural gas molecules like methane (CH4), which is a potent greenhouse gas with high energy density. The Mallik site at the Mackenzie Delta in the Canadian Arctic contains a large volume of technically recoverable CH4 hydrate beneath the base of the permafrost. Understanding how the sub-permafrost hydrate is distributed can aid in searching for the ideal locations for deploying CH4 production wells to develop the hydrate as a cleaner alternative to crude oil or coal. Globally, atmospheric warming driving permafrost thaw results in sub-permafrost hydrate dissociation, releasing CH4 into the atmosphere to intensify global warming. It is therefore crucial to evaluate the potential risk of hydrate dissociation due to permafrost degradation. To quantitatively predict hydrate distribution and volume in complex sub-permafrost environments, a numerical framework was developed to simulate sub-permafrost hydrate formation by coupling the equilibrium CH4-hydrate formation approach with a fluid flow and transport simulator (TRANSPORTSE). In addition, integrating the equations of state describing ice melting and forming with TRANSPORTSE enabled this framework to simulate the permafrost evolution during the sub-permafrost hydrate formation. A modified sub-permafrost hydrate formation mechanism for the Mallik site is presented in this study. According to this mechanism, the CH4-rich fluids have been vertically transported since the Late Pleistocene from deep overpressurized zones via geologic fault networks to form the observed hydrate deposits in the Kugmallit-Mackenzie Bay Sequences. The established numerical framework was verified by a benchmark of hydrate formation via dissolved methane. Model calibration was performed based on laboratory data measured during a multi-stage hydrate formation experiment undertaken in the LArge scale Reservoir Simulator (LARS). As the temporal and spatial evolution of simulated and observed hydrate saturation matched well, the LARS model was therefore validated. This laboratory-scale model was then upscaled to a field-scale 2D model generated from a seismic transect across the Mallik site. The simulation confirmed the feasibility of the introduced sub-permafrost hydrate formation mechanism by demonstrating consistency with field observations. The 2D model was extended to the first 3D model of the Mallik site by using well-logs and seismic profiles, to investigate the geologic controls on the spatial hydrate distribution. An assessment of this simulation revealed the hydraulic contribution of each geological element, including relevant fault networks and sedimentary sequences. Based on the simulation results, the observed heterogeneous distribution of sub-permafrost hydrate resulted from the combined factors of the source-gas generation rate, subsurface temperature, and the permeability of geologic elements. Analysis of the results revealed that the Mallik permafrost was heated by 0.8-1.3 °C, induced by the global temperature increase of 0.44 °C and accelerated by Arctic amplification from the early 1970s to the mid-2000s. This study presents a numerical framework that can be applied to study the formation of the permafrost-hydrate system from laboratory to field scales, across timescales ranging from hours to millions of years. Overall, these simulations deepen the knowledge about the dominant factors controlling the spatial hydrate distribution in sub-permafrost environments with heterogeneous geologic elements. The framework can support improving the design of hydrate formation experiments and provide valuable contributions to future industrial hydrate exploration and exploitation activities.}, language = {en} } @article{LiWangHerzschuhetal.2022, author = {Li, Zhen and Wang, Yongbo and Herzschuh, Ulrike and Cao, Xianyong and Ni, Jian and Zhao, Yan}, title = {Pollen-based biome reconstruction on the Qinghai-Tibetan Plateau during the past 15,000 years}, series = {Palaeogeography, palaeoclimatology, palaeoecology : an international journal for the geo-sciences}, volume = {604}, journal = {Palaeogeography, palaeoclimatology, palaeoecology : an international journal for the geo-sciences}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0031-0182}, doi = {10.1016/j.palaeo.2022.111190}, pages = {12}, year = {2022}, abstract = {Reconstruction of past vegetation change is critical for better understanding the potential impact of future global change on the fragile alpine ecosystems of the Qinghai-Tibetan Plateau (QTP). In this paper, pollen assemblages comprising 58 records from the QTP, spanning the past 15 kyrs, were collected to reconstruct biome compositions using a standard approach. Six forest biomes were identified mainly on the southeastern plateau, exhibiting a pattern of gradual expansion along the eastern margin during early to mid-Holocene times. The alpine meadow biome was separately identified based on an updated scheme, and showed notable westward expansions towards lower latitudes and higher altitudes during early Holocene times. Consistent patterns of migration could also be identified for the alpine steppe biome, which moved eastward during the late Holocene after 4 ka. As the dominant biome type, temperate steppe was distributed widely over the QTP with minor migration patterns, except for a progressive expansion to lower altitudes in the late Holocene times. The desert biome was inferred mainly as covering the northwestern plateau and the Qaidam Basin, in relatively restricted areas. The spatial distribution of the reconstructed biomes represent the large-scale vegetation gradient on the QTP. Monsoonal precipitation expressed predominant controls on the development of alpine ecosystems, while the variations in desert vegetation responded to regional moisture brought by the mid-latitude Westerlies. Temperature changes played relatively minor roles in the variations of alpine vegetation, but exerted more significant impacts on the forest biomes.}, language = {en} } @article{LiSpangenbergSchicksetal.2022, author = {Li, Zhen and Spangenberg, Erik and Schicks, Judith Maria and Kempka, Thomas}, title = {Numerical simulation of hydrate formation in the LArge-Scale Reservoir Simulator (LARS)}, series = {Energies : open-access journal of related scientific research, technology development and studies in policy and management}, volume = {15}, journal = {Energies : open-access journal of related scientific research, technology development and studies in policy and management}, number = {6}, publisher = {MDPI}, address = {Basel}, issn = {1996-1073}, doi = {10.3390/en15061974}, pages = {27}, year = {2022}, abstract = {The LArge-scale Reservoir Simulator (LARS) has been previously developed to study hydrate dissociation in hydrate-bearing systems under in-situ conditions. In the present study, a numerical framework of equations of state describing hydrate formation at equilibrium conditions has been elaborated and integrated with a numerical flow and transport simulator to investigate a multi-stage hydrate formation experiment undertaken in LARS. A verification of the implemented modeling framework has been carried out by benchmarking it against another established numerical code. Three-dimensional (3D) model calibration has been performed based on laboratory data available from temperature sensors, fluid sampling, and electrical resistivity tomography. The simulation results demonstrate that temperature profiles, spatial hydrate distribution, and bulk hydrate saturation are consistent with the observations. Furthermore, our numerical framework can be applied to calibrate geophysical measurements, optimize post-processing workflows for monitoring data, improve the design of hydrate formation experiments, and investigate the temporal evolution of sub-permafrost methane hydrate reservoirs.}, language = {en} } @article{LiSpangenbergSchicksetal.2022, author = {Li, Zhen and Spangenberg, Erik and Schicks, Judith Maria and Kempka, Thomas}, title = {Numerical Simulation of Coastal Sub-Permafrost Gas Hydrate Formation in the Mackenzie Delta, Canadian Arctic}, series = {Energies}, volume = {15}, journal = {Energies}, number = {14}, publisher = {MDPI}, address = {Basel}, issn = {1996-1073}, doi = {10.3390/en15144986}, pages = {25}, year = {2022}, abstract = {The Mackenzie Delta (MD) is a permafrost-bearing region along the coasts of the Canadian Arctic which exhibits high sub-permafrost gas hydrate (GH) reserves. The GH occurring at the Mallik site in the MD is dominated by thermogenic methane (CH4), which migrated from deep conventional hydrocarbon reservoirs, very likely through the present fault systems. Therefore, it is assumed that fluid flow transports dissolved CH4 upward and out of the deeper overpressurized reservoirs via the existing polygonal fault system and then forms the GH accumulations in the Kugmallit-Mackenzie Bay Sequences. We investigate the feasibility of this mechanism with a thermo-hydraulic-chemical numerical model, representing a cross section of the Mallik site. We present the first simulations that consider permafrost formation and thawing, as well as the formation of GH accumulations sourced from the upward migrating CH4-rich formation fluid. The simulation results show that temperature distribution, as well as the thickness and base of the ice-bearing permafrost are consistent with corresponding field observations. The primary driver for the spatial GH distribution is the permeability of the host sediments. Thus, the hypothesis on GH formation by dissolved CH4 originating from deeper geological reservoirs is successfully validated. Furthermore, our results demonstrate that the permafrost has been substantially heated to 0.8-1.3 degrees C, triggered by the global temperature increase of about 0.44 degrees C and further enhanced by the Arctic Amplification effect at the Mallik site from the early 1970s to the mid-2000s.}, language = {en} }