Carbonate Record of Past Thresholds, Critical Transitions and State Shifts in the Earth Systems

地球系统过去阈值、关键转变和状态转变的碳酸盐记录

• 批准号: RGPIN-2015-04662
• 负责人: Beauchamp, Benoit
• 金额: $ 2.99万
• 依托单位: University of Calgary
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=644871
• 关键词: Carbonate; Record; Past; Thresholds; Critical

Many fear that human activities are rapidly pushing our planet's biosphere and ecosystems towards an alternate state from which it will be impossible to go back. While no one can predict when the next state shift will occur, how fast the planet will tip into an alternate state, and what kind of world awaits us beyond the shift, the geological record provides some answers to these questions as the Earth has more than once undergone state shifts of global magnitude. The largest shifts were arguably the major mass extinctions that marked our geological past, and none were more devastating than the Latest Permian Extinction, 252 million years ago. In a scenario that many authors see as the harbinger of horrific things to come if we keep burning fossil fuel, more than 92% of living creatures disappeared from planet Earth over a short period of time. The Siberian Traps eruptions, the largest volcanic eruptions to ever occur, are increasingly fingered as a major cause of the global devastation from which it took Earth 5 million years to recover. However, it is also known that the Earth Systems crossed a series of irreversible thresholds over a 60 million year interval leading-up to that shift resulting in critical transitions that are especially well recorded in carbonate sediments. These are short-lived intervals of major change that took place some 310, 299, 293, 272, 262 and 252 million years ago. We here propose to examine these critical transitions through the study of the marine carbonate system, which was, as it is now, under increasing stress due to an increase in atmospheric carbon dioxide. This will best addressed in comparing and contrasting the critical transitions across widely separated localities. Thirteen students will be involved in various projects that wil be staged in Arctic Canada, Western USA, Europe and the Middle East. These areas used to exist along the western and eastern margins of the supercontinent Pangea, well before the onset of continental drift that led to the present continent configuration. All projects have a field component where students will be measuring and sampling detailed stratigraphic sections and a laboratory component where they will be acquiring additional microscopic and chemical data. Looking into the oceanic deterioration in the distant past is highly relevant to the modern climate change issue, especially considering that the composition and chemistry of the oceans was at that time similar to that of the modern oceans. Our research, while looking into the distant geological past, could generate credible predictions about how the world will change in the future in response to human activities.

许多人担心人类的活动正在迅速将我们的地球的生物圈和生态系统推向替代状态，从而将其返回。尽管没有人能预测下一次状态转变何时发生，但地球将使我们的替代状态变速，以及什么样的世界等待着我们超越转变，但地质记录为这些问题提供了一些答案，因为地球经历了不止一次的全球幅度变化。最大的转变可以说是标志着我们过去的地质过去的主要大规模灭绝，没有比2.52亿年前的最新二叠纪灭绝更具毁灭性的。在许多作者认为，如果我们不断燃烧化石燃料，许多作者将其视为可怕事物的预兆，超过92％的生物在短时间内从地球上消失了。西伯利亚陷阱爆发是有史以来最大的火山爆发，越来越多地作为全球破坏的主要原因，地球花了500万年才能恢复。但是，众所周知，地球系统在6000万年的间隔内越过一系列不可逆的阈值，导致这种转变，导致关键过渡，这些过渡在碳酸盐沉积物中尤为良好。这些是大约310、299、293、272、262和2.52亿年前发生的重大变化的短期间隔。我们在这里建议通过对海洋碳酸盐系统的研究来检查这些关键转变，因为现在，由于大气二氧化碳的增加，这正是在增加的压力下。这将在比较和对比广泛分开的地方的关键过渡时最好解决。 13名学生将参与各种项目，这些项目将在加拿大北极，美国，欧洲和中东进行。这些区域曾经在超大型Pangea的西部和东部边缘存在，就在大陆漂移开始之前，这导致了当前大陆的配置。所有项目都有一个野外组件，学生将在其中测量和采样详细的地层部分以及实验室组件，在该部分中，他们将获取其他显微镜和化学数据。研究遥远过去的海洋恶化与现代气候变化问题高度相关，尤其是考虑到当时海洋的组成和化学与现代海洋相似。我们的研究在研究遥远的地质过去时，可以产生关于对人类活动的响应，对世界将如何变化的可靠预测。