Research paper
Evidence of migration of main shocks during major seismo-volcanic crises of la soufrière (Guadeloupe, lesser antilles) in 1976

https://doi.org/10.1016/0377-0273(79)90007-6Get rights and content

Abstract

The few strongest shocks within several seismo-volcanic crises of La Soufrière were recorded by the event-triggered seismograph DMD on Dominique Island. Two P-wave arrivals, attributable to different paths of propagation, may be distinguished. The time interval between them changed for successive strong shocks in each crisis. The constraint on focal coordinates given by the local array around La Soufrière allows an interpretation of these observations, together with others from the Guadeloupe and Martinique arrays, in terms of a migration of successive strong shocks during a crisis, probably in an upward direction.

References (2)

  • J. Dorel et al.

    Report on the seismo-volcanic crisis 1975–1976 — La Soufrière

  • W.H.K. Lee et al.

    HYPO 71 (revised) : a computer program for determining hypocenter, magnitude, and first motion pattern of local earthquakes

    U.S. Geol. Surv. Open-file Rep.

    (1975)

Cited by (22)

  • Magnetic structure of Basse-Terre volcanic island (Guadeloupe, Lesser Antilles) inferred from 3D inversion of aeromagnetic data

    2017, Journal of Volcanology and Geothermal Research
    Citation Excerpt :

    Assuming a crustal thermal conductivity of 3 W/(m⋅K) and a steady state 1D conduction equation (i.e., a linear temperature vertical profile) or a half-space cooling model (Parsons and Sclater, 1977) yield in both cases to a depth to the Curie isotherm of ∼ 18 km (similar to the estimated depth to the bottom of magnetic sources mentioned above). The Curie temperature isotherm is, however, likely to be shallower beneath the volcanic island of Basse-Terre and especially below the Soufrière volcano where a magma chamber has been inferred at a depth of ∼ 6 km (e.g. Hirn and Michel, 1979; Pozzi et al., 1979; Boichu et al., 2011; Allard et al., 2014). Indeed, Bouligand et al. (2016) suggested a depth to the Curie temperature isotherm of the order of 5 km, assuming a temperature of ∼ 900° C for the magma chamber and a linear vertical temperature profile.

  • Steam and gas emission rate from La Soufriere volcano, Guadeloupe (Lesser Antilles): Implications for the magmatic supply during degassing unrest

    2014, Chemical Geology
    Citation Excerpt :

    Comparing with the contemporaneous seismic energy release is also interesting: over the past ten years the latter averaged 15 MJ yr− 1 (OVSG-IPGP reports) which, in terms of instantaneous mechanical energy release, corresponds to a trivial rate of 0.5 W. Therefore, in the present stage of activity the energy budget of La Soufrière is overwhelmingly due to hydrothermal manifestations. As introduced, La Soufrière hydrothermal activity is sustained by heat and gas transfer from a long-lived (> 30 ka; Touboul et al., 2007) andesitic magma reservoir, repeatedly replenished with basalt from below, whose roof stands at about 6–7 km depth beneath the summit (Hirn and Michel, 1979; Pozzi et al., 1979; Feuillard et al., 1983; Poussineau, 2005; Boudon et al., 2008). Petrologic experiments on the 1530 AD eruptive products (Poussineau, 2005) constrain that the reservoir is confined under mean P–T-redox conditions of 160 MPa (~ 6.5 km depth), ~ 875 °C and logfO2 ~ NNO + 0.8 (where NNO is the nickel–nickel oxide redox buffer).

  • Zn isotope compositions of the thermal spring waters of la soufrière volcano, guadeloupe island

    2014, Geochimica et Cosmochimica Acta
    Citation Excerpt :

    Except for the TA spring, all of the springs have relatively constant flow rates that range from 3 to 140 L/min (annual report of the Volcanic Observatory of Guadeloupe (OVSG), IPGP). Physico-chemical monitoring of these thermal springs has been performed by the OVSG since 1979 after the 1976–1977 seismo-volcanic crisis at La Soufrière (Feuillard et al., 1983; Hirn and Michel, 1979; Villemant et al., 2005). The increasing fumarolic activity since 1992 and HCl degassing since 1998 prompted the observatory to increase the surveillance of the volcano.

  • Noble gas isotopes in hydrothermal volcanic fluids of La Soufrière volcano, Guadeloupe, Lesser Antilles arc

    2012, Chemical Geology
    Citation Excerpt :

    The magma chamber depth was estimated at 6.2 ± 0.6 km using water content of glass inclusions in plagioclase crystals (Semet et al., 1981). This is strongly supported by seismic data (6.4 km) (Hirn and Michel, 1979) and magnetic observations (5–8 km) (Pozzi et al., 1979). Furthermore, that eruption produced a large compositional range of volcanic products, from andesite to basaltic andesite.

  • Degassing at La Soufrière de Guadeloupe volcano (Lesser Antilles) since the last eruptive crisis in 1975-77: Result of a shallow magma intrusion?

    2011, Journal of Volcanology and Geothermal Research
    Citation Excerpt :

    Earthquake foci for the period 1975–77 are located 0.5–6 km below sea level with most of them ranging in 1–3 km b.s.l. (Feuillard et al., 1983). The initiation of the rapid vertical migration of major earthquake swarms in 1976 (Hirn and Michel, 1979), as well as the source for geomagnetic field intensity anomalies observed in 1976–77 (Pozzi et al., 1979; Feuillard et al., 1983), were shown to be at a depth of ∼ 6 km. The chamber feeding the last magmatic eruption at La Soufrière was also estimated to be located at nearly the same depth, according to petrological studies (Semet et al., 1981).

View all citing articles on Scopus
View full text