{"title":"Melt viscosity tracks the volcanic and magmatic evolution of the 2021 Tajogaite eruption, La Palma (Canary Islands)","authors":"","doi":"10.1016/j.jvolgeores.2024.108210","DOIUrl":null,"url":null,"abstract":"<div><div>After more than 50 years of repose, on September 19th, 2021, a volcanic eruption began at the Cumbre Vieja ridge on La Palma, Canary Islands. The combined effusive and explosive activity generated a > 12 km<sup>2</sup> lava flow field with a new cone nearly 200 m higher than pre-eruptive topography and a vast tephra blanket. The immediate impact was locally devastating, destroying nearly 2000 buildings, blocking two main and numerous secondary roads, and inundating high-value agricultural land.</div><div>The hybrid nature of the eruption and the observed variations in eruption intensity motivated a thorough investigation of bulk liquid viscosity at high temporal resolution. Collection of 82 lava samples was achieved at a near daily resolution over the course of the 85-day-long event (through the end of the eruption on December 13th, 2021). All the samples were remelted, and liquid viscosity was measured in a concentric cylinder viscometer from 1490 °C down to incipient crystallization temperatures. These data constitute the highest temporal resolution viscosity dataset obtained for an eruptive sequence to date.</div><div>A tripartite viscosity pattern is identified at isothermal conditions: 1) during the fissure opening and establishing stage (days 1–20) a linear decrease in melt viscosity occurred; 2) during most of the eruption duration (days 21–70) viscosity was constant and 3) from day 70 until the end of the eruption viscosity increased again. We interpret this pattern as magma being extracted from different parts of the plumbing system over the course of the eruption. Accordingly, we show that viscosity time series can help shed light on some of the complexities of volcanic plumbing system. Additionally, the presented results highlight the monitoring potential of the viscosity assessment approach, specifically in regard to forecasting eruption behavior using direct information about magma mobility and detecting changes in magmatic plumbing system dynamics.</div></div>","PeriodicalId":54753,"journal":{"name":"Journal of Volcanology and Geothermal Research","volume":null,"pages":null},"PeriodicalIF":2.4000,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Volcanology and Geothermal Research","FirstCategoryId":"89","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0377027324002026","RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"GEOSCIENCES, MULTIDISCIPLINARY","Score":null,"Total":0}
引用次数: 0
Abstract
After more than 50 years of repose, on September 19th, 2021, a volcanic eruption began at the Cumbre Vieja ridge on La Palma, Canary Islands. The combined effusive and explosive activity generated a > 12 km2 lava flow field with a new cone nearly 200 m higher than pre-eruptive topography and a vast tephra blanket. The immediate impact was locally devastating, destroying nearly 2000 buildings, blocking two main and numerous secondary roads, and inundating high-value agricultural land.
The hybrid nature of the eruption and the observed variations in eruption intensity motivated a thorough investigation of bulk liquid viscosity at high temporal resolution. Collection of 82 lava samples was achieved at a near daily resolution over the course of the 85-day-long event (through the end of the eruption on December 13th, 2021). All the samples were remelted, and liquid viscosity was measured in a concentric cylinder viscometer from 1490 °C down to incipient crystallization temperatures. These data constitute the highest temporal resolution viscosity dataset obtained for an eruptive sequence to date.
A tripartite viscosity pattern is identified at isothermal conditions: 1) during the fissure opening and establishing stage (days 1–20) a linear decrease in melt viscosity occurred; 2) during most of the eruption duration (days 21–70) viscosity was constant and 3) from day 70 until the end of the eruption viscosity increased again. We interpret this pattern as magma being extracted from different parts of the plumbing system over the course of the eruption. Accordingly, we show that viscosity time series can help shed light on some of the complexities of volcanic plumbing system. Additionally, the presented results highlight the monitoring potential of the viscosity assessment approach, specifically in regard to forecasting eruption behavior using direct information about magma mobility and detecting changes in magmatic plumbing system dynamics.
期刊介绍:
An international research journal with focus on volcanic and geothermal processes and their impact on the environment and society.
Submission of papers covering the following aspects of volcanology and geothermal research are encouraged:
(1) Geological aspects of volcanic systems: volcano stratigraphy, structure and tectonic influence; eruptive history; evolution of volcanic landforms; eruption style and progress; dispersal patterns of lava and ash; analysis of real-time eruption observations.
(2) Geochemical and petrological aspects of volcanic rocks: magma genesis and evolution; crystallization; volatile compositions, solubility, and degassing; volcanic petrography and textural analysis.
(3) Hydrology, geochemistry and measurement of volcanic and hydrothermal fluids: volcanic gas emissions; fumaroles and springs; crater lakes; hydrothermal mineralization.
(4) Geophysical aspects of volcanic systems: physical properties of volcanic rocks and magmas; heat flow studies; volcano seismology, geodesy and remote sensing.
(5) Computational modeling and experimental simulation of magmatic and hydrothermal processes: eruption dynamics; magma transport and storage; plume dynamics and ash dispersal; lava flow dynamics; hydrothermal fluid flow; thermodynamics of aqueous fluids and melts.
(6) Volcano hazard and risk research: hazard zonation methodology, development of forecasting tools; assessment techniques for vulnerability and impact.