Article
Multidisciplinary Sciences
Zhouqiao Zhao, Bing Shen, Jian-Ming Zhu, Xianguo Lang, Guangliang Wu, Decan Tan, Haoxiang Pei, Tianzheng Huang, Meng Ning, Haoran Ma
Summary: The deglaciation of the Marinoan snowball Earth ice age was associated with intense continental weathering, recovery of primary productivity, transient marine euxinia, and potentially extensive CH4 emission. It is proposed that the deglacial CH4 emissions may have provided positive feedbacks for ice melting and global warming. The study suggests that active methanogenesis was fueled by methyl sulfides produced in sulfidic seawater during the deglacial recovery of marine primary productivity.
NATURE COMMUNICATIONS
(2021)
Article
Geology
D. O. Zakharov, D. R. Zozulya, D. P. Colon
Summary: Given the scarcity of reliable paleoclimate record, this study shows how analyzing the oxygen isotope values of surface precipitation recorded in Archean igneous and hydrothermal formations can help to understand the climate of early Earth.
Article
Geochemistry & Geophysics
Daniel Garduno Ruiz, Colin Goldblatt, Anne-Sofie Ahm
Summary: A one-dimensional atmospheric photochemical model is used to study the effect of temperature and humidity variations on the evolution of O2 and O3 during the Great Oxidation Event (GOE). It is found that changes in temperature and humidity can significantly impact the levels of O2 and O3, with higher temperatures and humidity leading to higher levels of these gases.
EARTH AND PLANETARY SCIENCE LETTERS
(2023)
Article
Geosciences, Multidisciplinary
T. M. Vandyk, C. Kettler, B. J. Davies, G. A. Shields, I Candy, D. P. Le Heron
Summary: This passage discusses the importance of ancient glacial deposits in understanding Earth's climate during the Cryogenian Period, as well as the challenges in determining the past positions of grounded ice, its thermal regime, and flow direction. The study found that Cryogenian subglacially striated surfaces are globally rare but are crucial indicators of the presence of ice and thermal regime.
PRECAMBRIAN RESEARCH
(2021)
Article
Meteorology & Atmospheric Sciences
Nicholas J. Edkins, Roger Davies
Summary: This study explores the impact of increased CO2 levels in the atmosphere on the expansion of the Earth's thermal layer in two directions. It is found that the expansion downward has a more significant effect on surface temperature, aiding in the deglaciation of a "Snowball Earth".
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
(2021)
Article
Physics, Fluids & Plasmas
Maura Brunetti, Charline Ragon
Summary: The climate is a complex system that tends towards a steady state under solar radiation and dissipative mechanisms. Bifurcation diagrams are useful tools for understanding the possible steady states, but constructing them can be time-consuming. Researchers tested two techniques for constructing bifurcation diagrams in a climate model, one involving random fluctuations in forcing and the other using estimates of internal variability and surface energy imbalance to find tipping points more precisely.
Article
Multidisciplinary Sciences
Kalin T. McDannell, C. Brenhin Keller, William R. Guenthner, Peter K. Zeitler, David L. Shuster
Summary: The origin of the Great Unconformity, a significant phenomenon in geosciences, has been a longstanding problem. Recent hypotheses suggest that it may be caused by either global continental exhumation during Cryogenian snowball Earth glaciations or diachronous episodic exhumation due to plate tectonic reorganization. By evaluating the Neoproterozoic thermal histories of four North American locations, this study supports the hypothesis of widespread cooling and erosion during the snowball Earth glaciations, but also acknowledges the influence of plate tectonic drivers on the thermal history of regions undergoing deformation. Further studies are needed to fully understand the extent and synchronicity of erosional exhumation.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2022)
Article
Geography, Physical
Zhouqiao Zhao, Yonggang Liu, Haijin Dai
Summary: This study uses a model to evaluate the rate and timescale of marine ice deglaciation, finding that it takes at most 300 to 1500 years and results in the formation of a freshwater lid.
GLOBAL AND PLANETARY CHANGE
(2022)
Review
Mathematics, Interdisciplinary Applications
Thomas E. Mulder, Heiko Goelzer, Fred W. Wubs, Henk A. Dijkstra
Summary: This study utilizes a novel fully-implicit Earth System Model of Intermediate Complexity (I-EMIC) to investigate transitions to Snowball Earth (SBE) states, revealing a complex bifurcation structure associated with the ice-albedo feedback. High-dimensional branches of the SBE bifurcation diagram are obtained through parameter continuation, allowing for the identification of stable and unstable equilibria. Additionally, large-scale linear stability analyses near major bifurcations uncover the spatial nature of destabilizing perturbations.
INTERNATIONAL JOURNAL OF BIFURCATION AND CHAOS
(2021)
Article
Biodiversity Conservation
Huw J. Griffiths, Rowan J. Whittle, Emily G. Mitchell
Summary: The timing of the first appearance of animals is crucial for understanding the evolution of life on Earth. The fossil record suggests a relatively recent origin, while molecular clock studies suggest a much earlier origination. Little attention has been given to how animal life would have survived during global glacial periods. Recent research on polar biota offers insights into the survival strategies and habitats of modern marine organisms in environments similar to those during Neoproterozoic glaciations.
GLOBAL CHANGE BIOLOGY
(2023)
Article
Multidisciplinary Sciences
Yongbo Peng, Huiming Bao, Ganqing Jiang, Peter Crockford, Dong Feng, Shuhai Xiao, Alan Jay Kaufman, Jiasheng Wang
Summary: A series of dramatic oceanic and atmospheric events occurred after the Marinoan snowball Earth meltdown, but the specifics of these events remain unclear. However, through the study of carbon and sulfur compounds in the Ediacaran period in South China, it was found that there was a period of high sulfate concentrations, possibly due to microbial activity. The study also found that this peak in sulfate concentrations occurred within approximately 50 ky since the onset of deglaciation, and it was likely a regional and transient event.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2022)
Article
Geosciences, Multidisciplinary
Benjamin W. Johnson, Colin Mettam, Simon W. Poulton
Summary: The history of the nitrogen cycle on Earth is closely linked to the redox evolution of the surface environment. Interpretation of nitrogen isotopic analyses in past environments requires linking with redox-sensitive proxies. Combining N isotope and redox analyses is essential to interpret biologic isotopic signals during times of dynamic redox in the ocean-atmosphere system.
FRONTIERS IN EARTH SCIENCE
(2022)
Article
Geography, Physical
Atena Shizuya, Kunio Kaiho, Jinnan Tong
Summary: This study used biomarker evidence to reveal the evolutionary processes during the late Neoproterozoic from the Marinoan glaciation to the early Ediacaran period. The results show the presence of photosynthetic activity, low productivity, and the expansion of eukaryotes during different stages of this transition.
GLOBAL AND PLANETARY CHANGE
(2021)
Article
Geochemistry & Geophysics
Qian Chen, He Liu, Tim Johnson, Michael Hartnady, Christopher L. Kirkland, Yongjun Lu, Wei-dong Sun
Summary: The temperature of the convecting mantle plays a significant role in controlling the rheology, composition, and tectonic behavior of the Earth's lithosphere. This study uses a statistical analysis of global sodic intracontinental basalts to investigate the evolution of mantle potential temperature over the past billion years. The findings reveal a relatively constant mantle temperature during the early Neoproterozoic period, followed by a rapid cooling event at the beginning of the Cryogenian.
EARTH AND PLANETARY SCIENCE LETTERS
(2022)
Article
Meteorology & Atmospheric Sciences
Johannes Hoerner, Aiko Voigt, Christoph Braun
Summary: Snowball Earth is a hypothesized state where the ocean was covered by sea ice, and this study investigates how the treatment of sea-ice thermodynamics affects its initiation. The results show that higher vertical resolution and brine pockets of ice increase the internal heat storage, making Snowball Earth initiation easier. However, limiting ice thickness has a minor impact on the initiation process. This study suggests that the internal heat storage of ice is an important factor to consider when modeling Snowball Earth initiation.
JOURNAL OF ADVANCES IN MODELING EARTH SYSTEMS
(2022)
Article
Geology
Daniel Paul Le Heron
Article
Geosciences, Multidisciplinary
Dilshad O. Ali, Anthony M. Spencer, Ian J. Fairchild, Ken J. Chew, Roger Anderton, Bruce K. Levell, Michael J. Hambrey, Dayton Dove, Daniel P. Le Heron
PRECAMBRIAN RESEARCH
(2018)
Article
Geosciences, Multidisciplinary
Daniel Paul Le Heron, Marie Elen Busfield, Dilshad Omer Ali, Saeed Al Tofaif, Thomas Matthew Vandyk
PRECAMBRIAN RESEARCH
(2018)
Article
Geosciences, Multidisciplinary
T. M. Vandyk, D. P. Le Heron, D. M. Chew, J. M. Amato, M. Thirlwall, C. M. Dehler, J. Hennig, S. R. Castonguay, T. Knott, S. Tofaif, D. O. Ali, C. J. Manning, M. E. Busfield, D. Doepke, N. Grassineau
JOURNAL OF THE GEOLOGICAL SOCIETY
(2018)
Article
Geology
Daniel Paul Le Heron, Thomas Matthew Vandyk, Hongwei Kuang, Yongqing Liu, Xiaoshuai Chen, Yuchong Wang, Zhenrui Yang, Lars Scharfenberg, Bethan Davies, Graham Shields
Article
Geology
Saeed Tofaif, Thomas M. Vandyk, Daniel P. Le Heron, John Melvin
SEDIMENTARY GEOLOGY
(2019)
Article
Geology
D. P. Le Heron, P. Dietrich, M. E. Busfield, C. Kettler, S. Bermanschlaeger, B. Grasemann
Article
Geosciences, Multidisciplinary
T. M. Vandyk, G. Wu, B. J. Davies, Y. Xiao, M. Li, G. A. Shields, D. P. Le Heron
PRECAMBRIAN RESEARCH
(2019)
Article
Geology
D. P. Le Heron, M. E. Busfield, C. Kettler
Summary: The discovery of abundant dropstones and striated clasts in the Chuos and Rasthof Formations in Namibia suggests the presence of an ice-rafting mechanism, challenging the conventional wisdom that dropstones should not occur in warm-water carbonates. This calls for a reevaluation of the depositional conditions of cap carbonates and their paleoclimatic significance.
Article
Geology
Daniel P. Le Heron, Christoph Kettler, Neil P. Griffis, Pierre Dietrich, Isabel P. Montanez, David A. Osleger, Axel Hofmann, Guilhem Douillet, Roland Mundil
Summary: This paper investigates the nature of contact between glacial rocks and underlying lithologies in different regions of southern Africa, revealing the processes and characteristics of ice mass expansion in different geographical areas. The study provides important insights into the geomorphological evolution during the glacial age.
DEPOSITIONAL RECORD
(2022)
Article
Geosciences, Multidisciplinary
Daniel Paul Le Heron, Christoph Kettler, Bethan J. Davies, Lars Scharfenberg, Lukas Eder, Michael Ketterman, Gerit E. U. Griesmeier, Rhiannon Quinn, Xiaoshuai Chen, Thomas Vandyk, Marie E. Busfield
Summary: The Gepatsch Glacier in Tirol, Austria has undergone significant changes in its forefield over a 12-month period, with alterations in both sediment and landforms. This study quantifies the rates of erosion and deposition in a complex proglacial setting, providing valuable insights into glaciation processes.
JOURNAL OF THE GEOLOGICAL SOCIETY
(2022)
Article
Geology
Daniel Paul Le Heron, Christoph Kettler, Arian Wawra, Martin Schoepfer, Bernhard Grasemann
Summary: The Pasterze, Austria's largest glacier, is rapidly melting and retreating. Recent sedimentary deposits, which have not been studied before, provide important insights into the distribution of facies expected from a dying valley glacier.
DEPOSITIONAL RECORD
(2022)
Article
Geosciences, Multidisciplinary
D. P. Le Heron, M. E. Busfield, A. J. B. Smith, S. Wimmer
Summary: New descriptions and analyses of the Makganyene Formation provide evidence for glacial control on sedimentation and modification of glacial diamictites by mass flow processes. A new model is proposed, suggesting deposition of a grounding zone wedge at an ancient, oscillating ice margin.
FRONTIERS IN EARTH SCIENCE
(2022)
Article
Geosciences, Multidisciplinary
Daniel Paul Le Heron, Nicholas Eyles, Marie Elen Busfield
AUSTRIAN JOURNAL OF EARTH SCIENCES
(2020)