Taking Earth's volcanic pulse: understanding global volcanic hazards by unlocking the ice core isotope archive

火山爆发将大量的火山灰和气体喷射到大气中。每年大约有5-10次大型火山事件，大约有7亿人（占世界人口的10%）居住在火山爆发时直接受到影响的附近。这些火山爆发可能导致重大的人类死亡，也可能对环境造成毁灭性的影响，火山灰和酸性沉降物覆盖了整个景观，破坏了庄稼，伤害了牲畜。尽管我们大多数英国人永远不会近距离目睹这些火山爆发，但它们仍然会影响我们的生活。2010年4月和5月冰岛Eyjafjallajökull火山的喷发就证明了这一点。虽然这次喷发规模相对较小，没有造成任何人死亡，但它扰乱了数百万人的出行，给全球经济造成了数十亿英镑的损失。这一紧急情况凸显了我们全球贸易和运输网络的脆弱性，以及英国不断受到火山事件破坏威胁的事实。火山学的主要目标之一是研究过去的火山事件，这样我们就可以了解它们的回归期和对环境的影响，并帮助社会为下一次“大”做好准备。令人惊讶的是，大爆发产生的火山产物具有区域性和全球性的分布，并且可以从喷发源传播数千公里。然而，在大多数地表环境中，这种细颗粒的火山沉降物很快就被冲走了。冰原是这方面的考察，通过在冰层上钻孔并提取冰芯，科学家们可以确定过去火山喷发沉积的富含硫层和火山灰。虽然冰芯提供了过去火山活动无可争议的最佳档案，但解释这些记录并不简单。我们面临的主要困难是了解源火山的位置以及它可能对气候造成的影响。即使在过去2500年的记录中，我们也只知道25次最大火山爆发中的7次的位置。如果科学家能够学会如何从这些记录中提取更多关于这些喷发的可能来源和环境影响的信息，这将是一个重大突破。这不仅可以帮助科学家在全球容易发生大型火山事件的地区进行火山监测，而且通过了解这些过去事件的频率和影响，我们可以为未来的火山爆发做好准备，并减少它们对经济的影响。我的项目将利用冰芯研究的最新分析突破。特别是，最近的分析表明，火山硫化学编码了关于火山柱在大气中达到的高度和喷发源与冰盖的接近程度的关键信息。因此，这种方法将提供有关火山位置及其气候影响的关键新信息（因为向大气中注入的羽流往往会导致最大的全球降温）。我将在几个著名的火山爆发中仔细研究这些技术，在那里我们已经有了关于它们的来源位置、喷发方式和气候影响的良好信息。一旦校准，我将使用这种化学指纹技术来确定过去2000年来所有重大喷发的喷发方式（羽流高度）和源头位置。因此，该项目将提供有关过去火山喷发的震级、频率和类型的关键信息，这些信息将用于改进对未来火山事件的预测。做好充分准备将有助于限制生命损失，减少经济损失。对于英国，我们将深入了解冰岛大型火山事件的爆发频率。为了全球社会，我们将帮助查明过去火山爆发的来源，并评估地球上改变气候的火山爆发的频率。

Explosive volcanic eruptions spew enormous quantities of ash and gas into the atmosphere. There are about 5-10 major volcanic events every year, and roughly 700 million people (10 % of the world's population) live close enough to be directly affected when they erupt. These eruptions may lead to significant human fatalities, and can also have devastating environmental impacts, covering the landscape in ash and acidic fallout, which destroys crops and harms livestock.Although most of us in the UK will never witness one of these eruptions up close they can still impact our lives. This was demonstrated by the eruption of Eyjafjallajökull volcano in Iceland in April and May 2010. Although the eruption was relatively minor and did not kill anyone, it disrupted the travel of millions of people and cost global economies billions of pounds. This emergency highlighted the vulnerability of our global trade and transport networks, and the fact that the UK is at constant threat from disruption by volcanic events. One of the key goals of volcanology is to study past volcanic events so that we can understand their return periods and environmental impacts, and help prepare society for the next 'big one'. Amazingly, the volcanic products from large explosive eruptions undergo regional and global distribution and can travel thousands of kilometres from their eruption source. However, in most surface environments this fine grained volcanic fallout is rapidly washed away and lost. Ice sheets are the expedition to this, and by drilling into the ice and extracting ice cores scientists can identify the sulphur-rich layers and ash deposited by these past eruptions. Although ice cores provide the undisputed best archive of past volcanism, interpreting this record is not straightforward. The main difficulties we face are understanding where the source volcano was located and what its climate impact might have been. Even in records that span the last 2500 years, we only know the location of 7 of the 25 largest volcanic eruptions. If scientists could learn how to extract more information about the likely source and environmental impacts of these eruptions from these records it would represent a major breakthrough. Not only would this help scientists target volcano monitoring in regions of the globe that are prone to large volcanic events, but by understanding the frequency and impacts of these past events we can prepare societies for future eruptions and reduce their economic impacts.My project will take advantage of recent analytical breakthroughs in ice core research. In particular, recent analyses suggest that volcanic sulphur chemistry encodes critical information about the height the volcanic plume reached in the atmosphere and the proximity of the eruptive source to the ice sheet. This method would therefore provide critical new information about where the volcano was located and its climate impact (since plumes injected higher into the atmosphere tend to cause the greatest global cooling). I will carefully interrogate these techniques for several well-known volcanic eruptions, where we already have good information on their source location, eruption style and climate impacts. Once calibrated, I will use this chemical fingerprinting technique to determine the eruptive style (plume height) and source location of all significant eruptions over the last 2000 years. Thus, this project will provide critical information about the magnitude, frequency and style of past eruptions which will be used to improve forecasts of future volcanic events. Being better prepared will help limit the loss of life and reduce the economic losses. For the UK, we'll gain a thorough understanding of the eruption frequency of large volcanic events in Iceland. For global society, we'll help pinpoint the source of past eruptions and evaluate the frequency of climate-changing eruptions on Earth.