GPS measurement of surface deformation around Soufriere Hills Volcano, Montserrat from October 1995 to July 1996

Abstract

Abstract. Global Positioning System geodesy was used to measure surface deformation on Soufriere Hills volcano, Montserrat from October 6, 1995 to July 1, 1997 during initial dome growth and gravitational collapse. Our data from this period show non-axially symmetric horizontal displacements, and decreasing subsidence as a function of radial distance from the former topographic high of the volcanic edifice. Forward modeling suggests that surface deformation is caused by a shallow vertical dike (< 3 km), which expanded approximately I m, coupled with a deflating Mogi source at about 6 km depth. These inferred source parameters are in good agreement with independent observations of regional dike widths and preeruption magma storage depth.

Unique strainmeter observations of Vulcanian explosions, Soufrière Hills Volcano, Montserrat, July 2003

“…[12] The conduit dimensions are constrained by spine dimensions, magma ascent rates and volume extrusion rates [Voight et al, 1999;Melnik and Sparks, 2002], and we assume for analysis a conduit diameter of 30 m. A transition from a cylindrical conduit to an underlying dike has been proposed for SHV [Mattioli et al, 1998;Costa et al, 2007;Hautmann et al, 2009;Linde et al, 2010], and for analysis we assume a nominal transition depth roughly 2 km beneath the vent at ∼700 m a.s.l. There is no suggestion in our strain data that a dike was depressurized, but this fact provides a useful constraint.…”

The use of Global Positioning System techniques for the continuous monitoring of landslides: application to the Super-Sauze earthflow (Alpes-de-Haute-Provence, France)

“…For the monitoring of crustal deformations, Larson and Agnew (1991) or Peler et al (1998) reach an accuracy of F 2 mm on 2 km-baselines. In the field of the environment, GPS was used: to follow the movements of spoil heaps or of quarry faces (Joass, 1993); to survey active volcanoes (Pingue et al, 1998;Mattioli et al, 1998;Sheperd et al, 1998) or major tectonic faults (Newmann et al, 1999); to monitor the flow and the behaviour of glaciers (Sjoberg et al, 2000) or snow thickness (Theakstone et al, 1999). The technique also applies, with a sufficient accuracy, to the monitoring of man-made structures, such as dams (Brown et al, 1999;Hudnut and Behr, 1998), bridges or viaducts.…”

Chapter 1 An overview of the eruption of Soufrière Hills Volcano, Montserrat from 2000 to 2010

“…Support for such a dyke comes from a variety of sources. Mattioli et al (1998) had argued for a shallow NW-trending dyke source above a Mogi source, based on early GPS data. argued that the tangential components of the 1997 tiltmeter record were non-zero and thus the source was non-axisymmetric.…”

“…Since 1997, it has been a statutory body of the Government of Montserrat and was initially managed by the British Geological Survey (BGS). The monitoring backbone of the MVO was established between 1995 and 2000: local networks of seismometers, continuous GPS (cGPS) receivers, spectroscopic measurements of sulphur dioxide and geodetic measurement of the gross shape of the lava dome (Mattioli et al 1998;Miller et al 1998;Neuberg et al 1998;Sparks et al 1998;White et al 1998;Young et al 1998;Gardner & White 2002 (Edmonds et al 2003a). The dome continued to be surveyed by a combination of groundbased photogrammetry with occasional helicopter-based photogrammetry, and ground-based and helicopter-based (June 2010) LiDAR (Light Detection And Ranging) survey.…”