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Externally triggered renewed bubble nucleation in basaltic magma: The 12 October 2008 eruption at Halema'uma'u Overlook vent, Kilauea, Hawai'i, USA

Citation

Carey, RJ and Manga, M and Degruyter, W and Swanson, D and Houghton, B and Orr, T and Patrick, M, Externally triggered renewed bubble nucleation in basaltic magma: The 12 October 2008 eruption at Halema'uma'u Overlook vent, Kilauea, Hawai'i, USA, Journal of Geophysical Research - Solid Earth, 117, (B11) Article B11202. ISSN 0148-0227 (2012) [Refereed Article]

Copyright Statement

Copyright 2012 American Geophysical Union

DOI: doi:10.1029/2012JB009496

Abstract

From October 2008 until present, dozens of small impulsive explosive eruptions occurred from the Overlook vent on the southeast side of Halema'uma'u Crater, at Kilauea volcano, USA. These eruptions were triggered by rockfalls from the walls of the volcanic vent and conduit onto the top of the lava column. Here we use microtextural observations and data from clasts erupted during the well-characterized 12 October 2008 explosive eruption at Halema'uma'u to extend existing models of eruption triggering. We present a potential mechanism for this eruption by combining microtextural observations with existing geophysical and visual data sets. We measure the size and number density of bubbles preserved in juvenile ejecta using 2D images and X-ray microtomography. Our data suggest that accumulations of large bubbles with diameters of >50 mu m to at least millimeters existed at shallow levels within the conduit prior to the 12 October 2008 explosion. Furthermore, a high number density of small bubbles <50 mu m is measured in the clasts, implying very rapid nucleation of bubbles. Visual observations, combined with preexisting geophysical data, suggest that the impact of rockfalls onto the magma free surface induces pressure changes over short timescales that (1) nucleated new additional bubbles in the shallow conduit leading to high number densities of small bubbles and (2) expanded the preexisting bubbles driving upward acceleration. The trigger of eruption and bubble nucleation is thus external to the degassing system.

Item Details

Item Type:Refereed Article
Research Division:Earth Sciences
Research Group:Geology
Research Field:Volcanology
Objective Division:Expanding Knowledge
Objective Group:Expanding Knowledge
Objective Field:Expanding Knowledge in the Earth Sciences
Author:Carey, RJ (Dr Rebecca Carey)
ID Code:81707
Year Published:2012
Web of Science® Times Cited:20
Deposited By:Centre for Ore Deposit Research - CODES CoE
Deposited On:2012-12-26
Last Modified:2017-11-02
Downloads:0

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