Rift volcanism: past, present and future

裂谷火山活动：过去、现在和未来

• 批准号: NE/L013649/1
• 负责人: Andrew Hooper
• 金额: $ 20.37万
• 依托单位: University of Leeds
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2014
• 资助国家: 英国
• 起止时间: 2014 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FL013649%2F1
• 关键词: Rift; volcanism; past; present; future

Early explorers called it Africa's Great Rift Valley, a narrow strip that runs for thousands of kilometres from Djibouti to Mozambique and is perhaps most famous for the vast herds of the Serengeti, mountain gorillas and dramatic landscapes of high peaks and fertile plains. The mountains and valleys are the signs of a continent slowly tearing apart. Moving apart more slowly than your finger nails grow, the African continent will one day split into two, creating a new ocean. As the Earth's crust stretches and thins - like plasticine when you pull it - rocks melt, and the resulting magma rises to the surface. The resultant eruptions have had a dramatic and varied impact on the landscape: great lakes have filled the holes left by enormous eruptions; eruptions of volcanic glass have created a chain of peaks, and wide fields are filled with scattered cones and lava flows. This volcanic landscape is hazardous - a recent report for the World Bank ranked 49 of Ethiopia's 65 volcanoes in the highest category of hazard uncertainty. The high temperatures associated with magma in the Rift Valley make it a rich source of carbon-neutral geothermal power. Multi-billion dollar investments by development agencies are driving a ten-fold expansion in the geothermal infrastructure in East Africa over the next decade. However, the majority of scientific research has focussed on volcanoes in other tectonic settings, such as Hawaii and Japan, leaving the volcanoes of the East African Rift largely a mystery. For many of them, we can't even say when the last eruption look place and there is no monitoring equipment to detect the early stages of an upcoming eruption. The eruption of Nabro volcano in 2011 was a timely reminder of the potential threats. Situated on the frontier between Ethiopia and Eritrea, the area is remote and sparsely populated, yet the eruption caused 32 fatalities, displaced >5000 people and disrupted regional aviation. Had this eruption originated from one of other 29 volcanoes with the same perceived hazard, but in densely-populated central Ethiopia, the humanitarian and societal cost would have been considerable. RiftVolc will focus on the volcanoes of the Main Ethiopian Rift in central Ethiopia. The aim is to understand their past behaviour, look for subtle signs of present-day activity and assess the threat posed to the infrastructure and people on and around them. RiftVolc will involve scientists from many disciplines working together to produce an integrated view of the past, present and future of the volcanoes in this region and compare it to other parts of East Africa and volcanoes elsewhere. Together we will spend several months out in Ethiopia, collecting samples, mapping the geology and deploying geophysical instruments, before returning to the lab to use analyse the data and create computer models of the results. Petrologists and geochemists will look at the lavas and ash to figure out the timing, size and style of past eruptions. Geophysicists will look for tiny earthquakes, changes in gravity, the passage of electrical currents and movements of the Earth's surface to understand the plumbing system feeding the volcanoes today. Finally, experts in hazard assessment will model possible scenarios and create a long-range eruption forecast for Ethiopia. We will work with our colleagues in the University of Addis Ababa and the Geological Survey of Ethiopia to ensure our findings are appropriate communicated to the government, industry and people of Ethiopia and with international groups such as the Global Volcano Model to communicate our results to development agencies such as the UN and the World Bank.

早期的探险者称它为非洲的大裂谷，这是一条从吉布提到莫桑比克长达数千公里的狭长地带，最著名的可能是塞伦盖蒂草原上庞大的兽群、山地大猩猩，以及高耸的山峰和肥沃的平原的壮观景观。山脉和山谷是大陆缓慢分裂的标志。非洲大陆分开的速度比你指甲生长的速度还慢，总有一天会分裂成两部分，形成一个新的海洋。随着地壳的拉伸和变薄——当你拉它的时候就像橡皮泥一样——岩石融化，由此产生的岩浆上升到地表。由此产生的火山喷发对地貌产生了巨大而多样的影响：大湖填补了大规模火山喷发留下的空洞；火山玻璃的喷发形成了一连串的山峰，广阔的田野上布满了散落的火山锥和熔岩流。这种火山景观是危险的——世界银行最近的一份报告将埃塞俄比亚65座火山中的49座列为危险不确定性最高的一类。与大裂谷岩浆相关的高温使其成为碳中性地热发电的丰富来源。发展机构数十亿美元的投资正在推动东非地热基础设施在未来十年扩大10倍。然而，大多数科学研究都集中在其他构造环境中的火山上，比如夏威夷和日本，使得东非裂谷的火山在很大程度上是一个谜。对其中许多人来说，我们甚至不能说最后一次喷发是什么时候，也没有监测设备来检测即将到来的喷发的早期阶段。2011年纳布罗火山的喷发及时地提醒了人们潜在的威胁。该火山位于埃塞俄比亚和厄立特里亚边境，地处偏远，人口稀少，但火山喷发造成32人死亡，5000人流离失所，并扰乱了地区航空。如果这次火山爆发起源于其他29座具有同样危险的火山之一，但发生在人口稠密的埃塞俄比亚中部，那么人道主义和社会成本将是相当大的。裂谷火山将集中在埃塞俄比亚中部的主要埃塞俄比亚裂谷的火山。其目的是了解他们过去的行为，寻找当今活动的微妙迹象，并评估对基础设施和周围人员构成的威胁。“裂谷火山”项目将让来自许多学科的科学家共同努力，对该地区火山的过去、现在和未来形成一个综合的看法，并将其与东非其他地区和其他地区的火山进行比较。我们将一起在埃塞俄比亚呆上几个月，收集样本，绘制地质地图，部署地球物理仪器，然后回到实验室分析数据，并为结果创建计算机模型。岩石学家和地球化学家将研究熔岩和火山灰，以确定过去火山喷发的时间、规模和风格。地球物理学家将寻找微小的地震，重力的变化，电流的通过和地球表面的运动来了解今天火山的管道系统。最后，危险评估专家将模拟可能的情景，并为埃塞俄比亚建立一个长期的火山爆发预测。我们将与亚的斯亚贝巴大学（University of Addis Ababa）和埃塞俄比亚地质调查局（Geological Survey of Ethiopia）的同事合作，确保我们的发现恰当地传达给埃塞俄比亚政府、行业和人民，并与全球火山模型（Global Volcano Model）等国际组织合作，将我们的结果传达给联合国和世界银行等发展机构。

项目成果

A multidisciplinary study of the final episode of the Manda Hararo dyke sequence, Ethiopia, and implications for trends in volcanism during the rifting cycle

• DOI: 10.1144/sp420.6
• 发表时间: 2015-05
• 期刊: Special Publications
• 作者: T. Barnie;D. Keir;I. Hamling;B. Hofmann;M. Belachew;Simon Carn;David Eastwell;Jos Hammond;A. Ayele;Clive Oppenheimer;Tim J. Wright

Rift Focussing and Magmatism During Late-Stage Rifting in Afar, Ethiopia

埃塞俄比亚阿法尔晚期裂谷期间的裂谷聚焦和岩浆作用

• DOI: 10.1002/essoar.10503895.1
• 发表时间: 2020
• 作者: Moore C

Eruption frequency and magnitude in a geothermally active continental rift: The Bora-Baricha-Tullu Moye volcanic complex, Main Ethiopian Rift

• DOI: 10.1016/j.jvolgeores.2022.107471
• 发表时间: 2022-01
• 期刊: Journal of Volcanology and Geothermal Research
• 影响因子: 2.9
• 作者: A. Tadesse;K. Fontijn;A. Melaku;E. Gebru;V. C. Smith;E. Tomlinson;D. Barfod;P. Gopon;F. Bégué;L. Caricchi;P. Laha;H. Terryn;S. Gudbrandsson;G. Yirgu;D. Ayalew

Volcanic activity and hazard in the East African Rift Zone.

• DOI: 10.1038/s41467-021-27166-y
• 发表时间: 2021-11-25
• 期刊: Nature communications
• 影响因子: 16.6
• 作者: Biggs J;Ayele A;Fischer TP;Fontijn K;Hutchison W;Kazimoto E;Whaler K;Wright TJ
• 通讯作者: Wright TJ

Routine Processing and Automatic Detection of Volcanic Ground Deformation Using Sentinel-1 InSAR Data: Insights from African Volcanoes

• DOI: 10.3390/rs14225703
• 发表时间: 2022-11
• 期刊: Remote. Sens.
• 作者: F. Albino;J. Biggs;M. Lazecký;Y. Maghsoudi