Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2017;79(6):46.
doi: 10.1007/s00445-017-1129-5. Epub 2017 May 24.

Magmatic gas percolation through the old lava dome of El Misti volcano

Yves Moussallam  1 , Nial Peters  1 , Pablo Masias  2 , Fredy Apaza  2 , Talfan Barnie  3 , C Ian Schipper  4 , Aaron Curtis  5 , Giancarlo Tamburello  6 , Alessandro Aiuppa  7   8 , Philipson Bani  9 , Gaetano Giudice  8 , David Pieri  5 , Ashley Gerard Davies  5 , Clive Oppenheimer  1
Affiliations

Magmatic gas percolation through the old lava dome of El Misti volcano

Yves Moussallam et al. Bull Volcanol. 2017.

Abstract

The proximity of the major city of Arequipa to El Misti has focused attention on the hazards posed by the active volcano. Since its last major eruption in the fifteenth century, El Misti has experienced a series of modest phreatic eruptions and fluctuating fumarolic activity. Here, we present the first measurements of the compositions of gas emitted from the lava dome in the summit crater. The gas composition is found to be fairly dry with a H2O/SO2 molar ratio of 32 ± 3, a CO2/SO2 molar ratio of 2.7 ± 0.2, a H2S/SO2 molar ratio of 0.23 ± 0.02 and a H2/SO2 molar ratio of 0.012 ± 0.002. This magmatic gas signature with minimal evidence of hydrothermal or wall rock interaction points to a shallow magma source that is efficiently outgassing through a permeable conduit and lava dome. Field and satellite observations show no evolution of the lava dome over the last decade, indicating sustained outgassing through an established fracture network. This stability could be disrupted if dome permeability were to be reduced by annealing or occlusion of outgassing pathways. Continued monitoring of gas composition and flux at El Misti will be essential to determine the evolution of hazard potential at this dangerous volcano.

Keywords: ASTER; Arequipa; Multi-GAS; Outgassing; Trail by fire; Volcanic hazard.

PubMed Disclaimer

Figures

Fig. 1
Fig. 1
Location map showing the location of El Misti volcanoes together with the location of all Peruvian Holocene volcanoes and the Nazca subduction trench. The centre of Arequipa (one million inhabitants) is located 18 km from El Misti’s summit
Fig. 2
Fig. 2
Visible (a) and infrared (b) images of the lava dome of El Misti taken on 1 December 2015 from within the crater, looking south. The dome is about 150 m across
Fig. 3
Fig. 3
CO2, H2O, H2S and H2 vs SO2 scatter plots of the mixing ratios in the El Misti plume. Measurements were taken on 1 December 2015 for 30 min at an acquisition frequency of 1 Hz. Least-square regression lines are shown in dotted blue on each plot. Red lines on the H2 vs SO2 scatter plot show a conservative estimate of the range of potential gas ratio
Fig. 4
Fig. 4
Still photograph of the El Misti lava dome taken from the crater rim during repeated ascent from 2007 to 2016 by OVI personnel. The pictures from 2008 were taken by Victor Aguilar (Universidad Naciona de San Agustin). Note the lack of changes in both the dome morphology and location of fumaroles
Fig. 5
Fig. 5
Satellite images of the El Misti lava dome from 2002 to 2016 taken from Google Earth and using images from Digital Globe, NASA, Landsat/Copernicus and CNES/Astrium. Note the lack of changes in both the dome morphology and location of the fumaroles field. Up is north on all images. The lava dome at the centre of each image is approximately 200 m in diameter
Fig. 6
Fig. 6
Time series of temperature anomalies (maximum temperature minus median temperature for all pixels in the summit area) derived from the ASTER AST08 land surface temperature product for El Misti and Sabancaya
Fig. 7
Fig. 7
Schematic cross-section through the El Misti conduit highlighting the main conclusions from this study. Magmatic gases are released from a reservoir at unknown depth and quickly migrating to the surface through a network of established fracture with the conduit and lava dome. During ascent, the gas has very limited chemical interaction with the host rock and remains isolated from contamination by the surrounding hydrothermal system
See this image and copyright information in PMC

References

    1. Aiuppa A, Shinohara H, Tamburello G, Giudice G, Liuzzo M, Moretti R (2011) Hydrogen in the gas plume of an open-vent volcano, Mount Etna, Italy. J Geophys Res 116:8 PP
    1. Aiuppa A, Giudice G, Liuzzo M, Tamburello G, Allard P, Calabrese S, Chaplygin I, McGonigle AJS, Taran Y. First volatile inventory for Gorely volcano. Kamchatka Geophys Res Lett. 2012;39:L06307.
    1. Aiuppa A, Robidoux P, Tamburello G, Conde V, Galle B, Avard G, Bagnato E, De Moor JM, Martínez M, Muñóz A. Gas measurements from the Costa Rica–Nicaragua volcanic segment suggest possible along-arc variations in volcanic gas chemistry. Earth Planet Sci Lett. 2014;407:134–147. doi: 10.1016/j.epsl.2014.09.041. - DOI
    1. Aiuppa A, Bani P, Moussallam Y, Di Napoli R, Allard P, Gunawan H, Hendrasto M, Tamburello G. First determination of magma-derived gas emissions from Bromo volcano, eastern Java (Indonesia) J Volcanol Geotherm Res. 2015;304:206–213. doi: 10.1016/j.jvolgeores.2015.09.008. - DOI
    1. Barriga, V. M., 1951. Los terremotos en Arequipa (1582–1868)

LinkOut - more resources