Geological Testing of Global Warming Models on Venus

金星上全球变暖模型的地质测试

• 批准号: RGPIN-2020-06408
• 负责人: Ernst, Richard
• 金额: $ 2.19万
• 依托单位: Carleton University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2021
• 资助国家: 加拿大
• 起止时间: 2021-01-01 至 2022-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=741191
• 关键词: Geological; Testing; Global; Warming; Models

Geological Testing of Global Warming Models on Venus On Earth, there is growing recognition that huge volcanic events (up to millions of km3) known as Large Igneous Provinces (LIPs) are major drivers of rapid climate change sometimes leading to mass extinctions (where up to 90% of life was obliterated). On Venus, a major pulse of LIP-style volcanism occurred ~700 million years ago and released a massive volume of carbon dioxide CO2. This caused extreme greenhouse warming to a current surface temperature of 450oC (twice as hot as your oven), and an atmosphere 90 times as dense as that of the Earth and composed of composed of 96% CO2. As a consequence, there is no liquid water on the surface of Venus and therefore no significant water erosion. However, it has recently been proposed that prior to this hyper-warming event Venus had conditions that were more Earth-like, even including the presence of oceans and rivers, and the potential for life. I propose that this dramatic climate change model for Venus can be evaluated through geological mapping (using Magellan spacecraft radar data) of two types of units: older units called tesserae which could represent rocks like those of the Canadian shield, and younger widespread basaltic lava flows (similar to Hawaii) that cover 90% of Venus. Tesserae would have been emplaced prior to global warming at a time when there could have been water erosion on Venus. Our hypothesis is also that the earliest basaltic lava flows on Venus were also emplaced during cooler (Earth-like) conditions, while the later basaltic flows would have been emplaced under the much hotter current conditions. Our team has recently discovered evidence for water erosion in tesserae, consistent with the modelling. This discovery indicates that tesserae could have a much longer geological history than previously believed, maybe even extending back 4 billion years, like the earliest rocks on Earth. I propose a campaign of systematic mapping of tesserae (of their erosional history, linear structures and superimposed lava ponds) to help unravel their protracted geological history. I also propose a systematic detailed mapping of the oldest volcanic plains in order to identify the transition in climate from Earth-like to inhospitable, by identifying units exhibiting erosion being cut by units exhibiting no erosion. My research will provide geological constraints on this runaway greenhouse climate change on Venus that will provide insights into the risks of modern global warming on Earth. My research will allow comparison of the volcanic history of Venus with that of Earth. Given an early Earth-like history for Venus, the obvious question is why Venus took a different path than Earth. One possible answer is that Venus experienced multiple pulse of volcanism that increased temperature beyond a tipping point. If so perhaps Venus offers a perspective into Earth's future. This research will train three MSc and two PhD students.

对地球上金星上全球变暖模型的地质测试，人们越来越认识到，巨大的火山事件（多达数百万km3）被称为大火成点省（嘴唇）是快速气候变化的主要驱动因素，有时会导致大规模灭绝（在其中最多可90％的寿命被消灭了）。 在金星上，大约7亿年前发生了唇形的火山，并释放了大量二氧化碳CO2。这导致极端温室变暖至当前的450oC（高度是烤箱的热），并且大气的密度是地球的密度90倍，由96％的CO2组成。结果，金星表面没有液态水，因此没有明显的水侵蚀。但是，最近有人提出，在这次超热事件之前，金星的条件更像是地球，即使包括海洋和河流的存在以及生命的潜力。 我建议，可以通过两种类型的单位来评估这种金星的戏剧性气候变化模型（使用Magellan航天器雷达数据）：较旧的单位称为Tesserae，可以代表像加拿大盾牌的岩石，以及年轻的大型基底熔岩流量（类似于夏威夷）覆盖金星的90％。在金星上可能出现水侵蚀的时候，泰塞拉将在全球变暖之前体会。我们的假设还是，在冷却器（类似地球）条件下，金星上最早的玄武岩熔岩流也被安置，而后来的玄武岩流则在当前较热的情况下会被扩散。 我们的团队最近发现了与建模相一致的Tesserae水侵蚀的证据。这一发现表明，泰塞拉（Tesserae）的地质历史可能比以前认为的要长得多，甚至可能延长了40亿年，就像地球上最早的岩石一样。我提出了针对泰瑟埃（Tesserae）（其侵蚀史，线性结构和叠加熔岩池塘）进行系统地图的运动，以帮助揭开其旷日持久的地质历史。我还提出了对最古老的火山平原的系统详细映射，以确定气候从地球样到不荒地的过渡，通过识别显示出没有表现出侵蚀的单位削减侵蚀的单位。 我的研究将对金星的这种失控的温室气候变化提供地质限制，这将洞悉地球上现代全球变暖的风险。我的研究将使金星的火山历史与地球的火山历史进行比较。考虑到金星的早期地球般的历史，显而易见的问题是为什么金星走了一条与地球不同的道路。一个可能的答案是，金星经历了多重的火山脉冲，使温度增加了临界点。如果是这样的话，也许金星提供了对地球未来的看法。 这项研究将培训三名MSC和两名博士生。