Causes, and impacts of lahars generated by the April, 2015 eruption of Calbuco volcano, Chile

2015 年 4 月智利卡尔布科火山喷发产生的泥流的原因和影响

基本信息

批准号：
NE/N007263/1
负责人：
Andrew Russell
金额：
$ 6.66万
依托单位：
Newcastle University
依托单位国家：
英国
项目类别：
Research Grant
财政年份：
2015
资助国家：
英国
起止时间：
2015 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=NE%2FN007263%2F1
关键词：
Causes impacts lahars generated April

项目摘要

Calbuco is a 2015m high, glacier capped, stratovolcano in the heavily populated Los Lagos district of southern Chile (41 degrees 19'48"S 72 degrees 37'06"W) with a history of very large volcanic eruptions in 1893-95, 1906-7, 1911-12, 1917, 1932, 1945, 1961 and 1972. On 22 April, 2015 Calbuco experienced a powerful 90 minute eruption at 18:04h followed by additional major eruptions at 01:00h and 13:10h on 23 & 30 April, respectively, resulting in the evacuation of 6500 people and the imposition of a 20 km radius exclusion zone. These eruptions generated ash plumes up to 15 km high, causing widespread disruption and damage to property to the NE of Calbuco. Hot pyroclastic flows (glowing avalanches) descended into several river catchments radiating from the volcano transforming into hot floods of water and sediment known as lahars which travelled distances of up to 14 km, reaching surrounding populated areas resulting in extensive damage to infrastructure and property. Although Calbuco, along with other nearby glaciated volcanoes in the Andes, has experienced recent reductions in the size of its glaciers, the current eruption indicates that even volcanoes with small glacier ice volumes can generate significant lahars. Our scientific goal is to determine the causes, dynamics and impacts of lahars generated during the ongoing Calbuco eruption. To achieve our goals we will undertake fieldwork on the volcano as soon as is practically possible. In the field we'll catalogue the immediate geomorphic and sedimentary impact of lahars on the river valleys systems surrounding Calbuco. We'll Identify lahar wash marks and will survey these use differential satellite positioning systems and ground based laser scanning. We'll conduct a helicopter based laser scanning survey of the lahar channels and will also use an airborne Radar to determine the presence and thickness of any ice left on the mountain after these eruptions. We'll sample and describe the vertical characteristics of these fresh lahar deposits in detail. The Calbuco eruption provides an exceptional opportunity to examine the dynamics and sedimentary signature of rare hot lahars, as they are still cooling and degassing. We plan to conduct fieldwork as soon as possible before the onset of subsequent volcanic and rainfall-induced lahars which may mask the signature of these earlier events. Our research will contribute to a better understanding of hazardous lahar processes with the hope of reducing the risk to population.

卡尔布科（Calbuco）是一个2015m高，冰川盖的高度，stratovolcano，位于人口稠密的智利南部洛斯拉各斯地区（41度19'48” S 72度37'06“ W），其历史悠久2015年Calbuco在18：04H进行了强大的90分钟爆发，随后在4月23日和30日在01：00h和13：10h进行了额外的重大爆发，导致撤离6500人，并强加了20 km的半径排除区。这些喷发产生的灰羽高达15公里，从而对Calbuco NE造成了广泛的破坏和财产的损害。热的火山碎屑流（发光的雪崩）降落到几条河流集水区，从火山转变为被称为Lahars的热洪水和沉积物，它们的距离达到14公里，到达周围人口稠密的地区，导致广泛的基础设施和财产损失。尽管卡尔布科（Calbuco）以及安第斯山脉（Andes）中附近的其他冰川火山的冰川大小降低，但目前的喷发表明，即使是带有小冰川冰量的火山也会产生大量的拉哈尔人。我们的科学目标是确定正在进行的Calbuco爆发过程中产生的拉哈尔人的原因，动态和影响。为了实现我们的目标，我们将尽快在火山上进行现场工作。在现场，我们将分类拉哈尔人对卡尔布科河谷系统的直接地形和沉积物影响。我们将确定Lahar Wash标记，并将使用差分卫星定位系统和地面激光扫描进行调查。我们将对Lahar通道进行基于直升机的激光扫描调查，还将使用空中雷达来确定这些爆发后山上剩下的任何冰的存在和厚度。我们将详细介绍这些新鲜的拉哈尔沉积物的垂直特征。 Calbuco爆发为检查稀有热拉哈尔人的动态和沉积物标志提供了极大的机会，因为它们仍在冷却和脱气。我们计划在随后的火山和降雨引起的拉哈尔人开始之前尽快进行实地调查，这可能掩盖这些早期事件的签名。我们的研究将有助于更好地了解危险的拉哈尔进程，以期降低人口的风险。