adrianadtkiewicz博士是在一次前往燧发山脉的实地考察中受到启发的，目的是了解火山活动是如何将我们的蓝点变成一颗冰封的星球的。 他们与dietmar muller教授和earthbyte小组一起得出了答案。 7.17亿–6.64亿年前澳大利亚北部燧发山脉的斯图特冰川沉积。 该研究的主要作者adrianadtkiewicz博士指出了一个厚厚的冰川沉积物床。 图片：悉尼大学dietmar müller教授澳大利亚地质学家利用板块构造模型来确定是什么最有可能导致地球历史上7亿年前的极端冰河时期气候。 这项发表在《地质学》上的研究有助于我们理解地球内置恒温器的功能，该恒温器可以防止地球陷入过热模式。 它还显示了全球气候对大气碳浓度的敏感程度。 该研究的主要作者、arc未来研究员adriana dutkiewicz博士说：“想象一下地球几乎完全冻结了。”。 “这正是大约7亿年前发生的事情；地球从两极到赤道都被冰覆盖，气温骤降。 然而，究竟是什么原因导致了这种情况一直是一个悬而未决的问题。 “我们现在认为我们已经解开了这个谜团：历史上火山二氧化碳排放量很低，这得益于现在加拿大一大堆火山岩的风化作用；这一过程吸收了大气中的二氧化碳。 该项目的灵感来源于这一时期古代冰川作用留下的冰川碎片，这些碎片可以在南澳大利亚的弗林德斯山脉中壮观地观察到。 最近，由合著者、阿德莱德大学的艾伦·科林斯教授带领的一次地质实地考察促使该团队使用悉尼大学earthbyte计算机模型来调查这一冰河时期的原因和异常漫长的持续时间。 19世纪欧洲殖民地探险家查尔斯·斯图特在澳大利亚中部发现了延长的冰河期，也被称为斯图冰川期，从7.17亿年前一直延续到6.6亿年前，这一时期远远早于恐龙和陆地上复杂植物的存在。 斯图尔特冰河时期的板块构造来源：ben mather和dietmar müllerdr dutkiewicz说：“人们已经提出了引发和结束这一极端冰河时期的各种原因，但最神秘的方面是为什么它持续了5700万年——这是我们人类难以想象的时间跨度。 “研究小组回到了一个板块构造模型，该模型显示了古代超级大陆罗地那解体后大陆和海洋盆地的演变。 他们将其与一个计算机模型连接起来，该模型计算了大洋中脊海底火山的二氧化碳脱气作用。大洋中脊是板块分叉和新地壳诞生的地方。 他们很快意识到，斯氏冰河时代的开始与火山二氧化碳排放量的历史最低水平正相关。 此外，在整个冰河时期，二氧化碳排放量都相对较低。 dutkiewicz博士说：“当时，地球上没有多细胞动物或陆地植物。 大气中的温室气体浓度几乎完全由火山释放的二氧化碳和消耗二氧化碳的硅酸盐岩石风化过程决定。 dietmar müller教授指出，在燧石山脉的sturt地层上覆盖着碳酸盐岩。 图片：adrianadtkiewicz博士合著者悉尼大学的dietmar müller教授说：“地质在这个时候统治着气候。 我们认为，斯氏冰河时代的开始是双重打击：板块构造重组将火山脱气降至最低，而与此同时，加拿大的一个大陆火山区开始侵蚀，消耗大气中的二氧化碳。 “结果是大气中的二氧化碳浓度下降到冰川作用开始的水平，我们估计这一水平低于百万分之200，不到今天水平的一半。 “这些团队的工作提出了关于地球长期未来的有趣问题。 最近的一个理论提出，在接下来的2.5亿年里，地球将向最后的穿山甲进化，这是一个非常热的超级大陆，哺乳动物可能会灭绝。 然而，随着大陆碰撞的增加和板块的减速，地球目前也处于火山二氧化碳排放量较低的轨道上。 所以，也许最后盘古会再次变成雪球。 dutkiewicz博士说：“无论未来如何，重要的是要注意，这里研究的那种地质气候变化发生得非常缓慢。 据美国国家航空航天局称，人类引发的气候变化的速度是我们以前看到的10倍。 dutkiewicz，a。 等人（地质学，2024）。 doi:10。 1130/g51669。 1earthbyte小组这项工作是由悉尼大学earthbytte小组开发的gplates板块构造软件实现的，该软件是过去十年中一系列发现的基础，为地质学如何成为气候和生物多样性的长期核心驱动因素贡献了重要知识。 gplates的开发得到了auscope国家合作研究基础设施系统（ncris）计划的支持。 声明作者声明没有相互竞争的利益。 这项研究的部分资金来自澳大利亚研究委员会。dr adriana dutkiewicz was inspired during a field trip to the flinders ranges to find out how volcanic activity turned our blue dot to an ice covered planet. together with professor dietmar muller and the earthbyte group, theyve produced an answer. deposits from the sturtian glaciation 717–664 million years ago in the northern flinders ranges, australia. research lead author dr adriana dutkiewicz pointing to a thick bed of glacial deposits. photo: professor dietmar müller/university of sydneyaustralian geologists have used plate tectonic modelling to determine what most likely caused an extreme ice-age climate in earth’s history, more than 700 million years ago.the study, published in geology, helps our understanding of the functioning of the earths built-in thermostat that prevents the earth from getting stuck in overheating mode. it also shows how sensitive global climate is to atmospheric carbon concentration.“imagine the earth almost completely frozen over,” said the study’s lead author, arc future fellow dr adriana dutkiewicz. “that’s just what happened about 700 million years ago; the planet was blanketed in ice from poles to equator and temperatures plunged. however, just what caused this has been an open question.“we now think we have cracked the mystery: historically low volcanic carbon dioxide emissions, aided by weathering of a large pile of volcanic rocks in what is now canada; a process that absorbs atmospheric carbon dioxide.”the project was inspired by the glacial debris left by the ancient glaciation from this period that can be spectacularly observed in the flinders ranges in south australia.a recent geological field trip to the ranges, led by co-author professor alan collins from the university of adelaide, prompted the team to use the university of sydney earthbyte computer models to investigate the cause and the exceptionally long duration of this ice age.the extended ice age, also called the sturtian glaciation after the 19th century european colonial explorer of central australia, charles sturt, stretched from 717 to 660 million years ago, a period well before the dinosaurs and complex plant life on land existed.plate tectonics during sturtian ice agecredit: ben mather and dietmar müllerdr dutkiewicz said: “various causes have been proposed for the trigger and the end of this extreme ice age, but the most mysterious aspect is why it lasted for 57 million years – a time span hard for us humans to imagine.”the team went back to a plate tectonic model that shows the evolution of continents and ocean basins at a time after the breakup of the ancient supercontinent rodina. they connected it to a computer model that calculates co2 degassing of underwater volcanoes along mid-ocean ridges – the sites where plates diverge and new ocean crust is born.they soon realised that the start of the sturtian ice age precisely correlates with an all-time low in volcanic co2 emissions. in addition, the co2 outflux remained relatively low for the entire duration of the ice age.dr dutkiewicz said: “at this time, there were no multicellular animals or land plants on earth. the greenhouse gas concentration of the atmosphere was almost entirely dictated by co2 outgassing from volcanoes and by silicate rock weathering processes, which consume co2.”professor dietmar müller points to carbonates overlying the sturt formation in the flinders ranges. photo: dr adriana dutkiewiczco-author professor dietmar müller from the university of sydney said: “geology ruled climate at this time. we think the sturtian ice age kicked in due to a double whammy: a plate tectonic reorganisation brought volcanic degassing to a minimum, while simultaneously a continental volcanic province in canada started eroding away, consuming atmospheric co2.“the result was that atmospheric co2 fell to a level where glaciation kicks in – which we estimate to be below 200 parts per million, less than half today’s level.”the teams work raises intriguing questions about earths long-term future. a recent theory proposed that over the next 250 million years, earth would evolve towards pangea ultima, a supercontinent so hot that mammals might become extinct.however, the earth is also currently on a trajectory of lower volcanic co2 emissions, as continental collisions increase and the plates slow down. so, perhaps pangea ultima will turn into a snowball again.dr dutkiewicz said: “whatever the future holds, it is important to note that geological climate change, of the type studied here, happens extremely slowly. according to nasa, human-induced climate change is happening at a pace 10 times faster than we have seen before.”research‘duration of sturtian “snowball earth” glaciation linked to exceptionally low mid-ocean ridge outgassing’, dutkiewicz, a. et al (geology, 2024). doi: 10.1130/g51669.1earthbyte groupthis work was enabled by the gplates plate tectonic software, developed by the earthbyte group at the university of sydney, which has been the basis of a slew of discoveries over the past decade, contributing significant knowledge to how geology is a central long-term driver of climate and biodiversity. gplates development is supported by the auscope national collaborative research infrastructure system (ncris) program.declarationthe authors declare no competing interests. research was in part funded by the australian research council.亲，点击此处在线申请留学咨询服务和报名评估！我们将竭诚提供最佳评估服务！
