uu.seUppsala University Publications
Change search
ReferencesLink to record
Permanent link

Direct link
Evidence for high fluid/melt content beneath Krakatau volcano (Indonesia) from local earthquake tomography
Show others and affiliations
2011 (English)In: Journal of Volcanology and Geothermal Research, ISSN 0377-0273, Vol. 206, no 3-4, 96-105 p.Article in journal (Refereed) Published
Abstract [en]

Within the KRAKMON project for multiparameter monitoring of Anak Krakatau volcano (Indonesia), a network of temporary stations was installed on the islands of the Krakatau complex as well as in the surrounding areas of the Sunda Strait, Sumatra and Java. The network was operated from June 2005 until January 2006. More than 700 local events were recorded during this experiment, and travel times from these events were used to perform a tomographic inversion for P and S velocities and for the Vp/Vs ratio. In this study, special attention was paid to the validation of the computed model based on different tests, such as inversion of independent data subsets and synthetic modeling. Although the network configuration and the distribution of the events are not favorable for high-quality tomographic imaging, we have obtained some important and robust features which give information about sources of volcanic activity in the Krakatau complex. The most interesting feature of this study is a zone of high Vp/Vs ratio beneath the Krakatau complex. At depths down to 4 km depth we observe anticorrelation of higher P- and lower S-velocities that leads to Vp/Vs ratio higher than 2. This is a probable indicator of the presence of partially molten and/or with high fluid content material with a composition corresponding to deeper layers. It is important that the anomaly of high Vp/Vs ratio beneath the Krakatau complex appears to be separated in two parts at a depth of 5-6 km. This fits to results of geobarometric analysis that presume the existence of several levels of magma chambers beneath Anak Krakatau.

Place, publisher, year, edition, pages
2011. Vol. 206, no 3-4, 96-105 p.
Keyword [en]
Seismic tomography, Krakatau, Volcanism, Magma chamber
National Category
Earth and Related Environmental Sciences
Research subject
Earth Science with specialization in Mineral Chemistry, Petrology and Tectonics
URN: urn:nbn:se:uu:diva-160412DOI: 10.1016/j.jvolgeores.2011.06.009ISI: 000295502900005OAI: oai:DiVA.org:uu-160412DiVA: diva2:450889
Available from: 2011-10-24 Created: 2011-10-24 Last updated: 2016-01-13Bibliographically approved
In thesis
1. Magma plumbing architecture in Indonesia and the North Atlantic Igneous Province
Open this publication in new window or tab >>Magma plumbing architecture in Indonesia and the North Atlantic Igneous Province
2016 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Magma plumbing systems represent the physical framework of magma transport and storage from the source region in the mantle, through the crust, until reaching the surface in a volcanic eruption. Characterising the different aspects of magma plumbing, in particular the distribution of magma storage zones throughout the crust, is of key importance to better understand the behaviour of individual volcanoes. In particular, shallow crustal magma storage and associated magma-crust interaction processes could potentially explain some of the worlds most unpredictable and explosive volcanoes. This thesis studies magma plumbing architecture in the Sunda Arc (Indonesia), and the North Atlantic Igneous Province, based on elemental and isotope geochemistry, and derived petrological modelling.

In this study, I have employed petrological models, so called geothermobarometers, to calculate pressures and temperatures (P-T) of crustal magma storage. Geothermobarometers are calibrated thermodynamic formulations based on the composition of magmatic minerals and their co-existing melt as a function of the P-T conditions of crystallisation. Using the calculated P-T estimates, I was able to derive the depth of magma storage, and thereby reconstruct the architecture of magma storage systems. A number of different geothermobarometers based on different mineral phases, including plagioclase, clinopyroxene and olivine, were used for this purpose,

The geothermobarometric modelling was combined with additional elemental and isotope geochemical analyses, as well as collaborations with geophysical investigations. These additional approaches were used to corroborate the findings of the geothermobarometric modelling, and also to model and quantify magma-crust interaction processes that take place during crustal magma storage, such as assimilation of crustal lithologies into the magmatic system.

The findings of this thesis build upon the growing body of evidence in support of the prevalence of shallow magma storage in different volcanic settings worldwide. This realisation is relevant to volcano monitoring and hazard mitigation worldwide.

Place, publisher, year, edition, pages
Uppsala: Acta Universitatis Upsaliensis, 2016. 46 p.
Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, ISSN 1651-6214 ; 1328
magma plumbing, geothermobarometry, plagioclase, clinopyroxene, magma-crust interaction, hazard mitigation
National Category
Research subject
Earth Science with specialization in Mineral Chemistry, Petrology and Tectonics
urn:nbn:se:uu:diva-267764 (URN)978-91-554-9430-8 (ISBN)
Public defence
2016-01-28, Hambergsalen, Geocentrum, Villavägen 16, Uppsala, 10:00 (English)
Available from: 2016-01-04 Created: 2015-11-26 Last updated: 2016-01-13

Open Access in DiVA

No full text

Other links

Publisher's full text

Search in DiVA

By author/editor
Dahrén, BörjeTroll, Valentin R.
By organisation
Solid Earth Geology
In the same journal
Journal of Volcanology and Geothermal Research
Earth and Related Environmental Sciences

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Altmetric score

Total: 193 hits
ReferencesLink to record
Permanent link

Direct link