The 1975–1977 crisis of la Soufriere de Guadeloupe (F.W.I): A still-born magmatic eruption

Water Circulations on La Soufriere Volcano Inferred by Self-Potential Surveys (Guadeloupe, Lesser Antilles). Renew of Volcanic Activity?

“…The first landslide occurred in June 1976 in Galion river, and the first phreatic explosion (July 8, 1976) reopened the east-south-east 1956 fracture. From September, 1976, the volcanic activity progressively receded (Feuillard et al, 1983;Zlotnicki, 1986). Till 1992, only five short time seismic swarms beneath the dome or its immediate vicinity were recorded (Table 1).…”

Challenges of Volcanic Crises on Small Islands States

“…In contrast to previous phreatic eruptions of La Soufrière and elsewhere in the Caribbean, a significant period of increasing volcanic seismicity was recorded and felt in Guadeloupe starting in July 1975, one year prior to the onset of the eruption. This unprecedented and rapidly escalating level of recorded and felt seismicity (Dorel and Feuillard 1980;Feuillard et al 1983;Feuillard 2011), which in June 1976 reached levels that were 175 times the baseline monthly rate, was not accompanied by any modification of fumarolic activity. The eruption began with an unexpected explosion on 8 July 1976.…”

“…The eruption began with an unexpected explosion on 8 July 1976. The subsequent 9-month long period of explosive and ash-venting activity was interpreted as a still-born or failed magmatic event (Feuillard et al 1983;Villemant et al 2005;Boichu et al 2011). Syn-eruptive degassing (H 2 O, minor CO 2 , H 2 S, SO 2 ) with acid condensates (HCl, HF, Br) led to moderate environnmental impact with short-term public health implications.…”

Muon tomography: Plans for observations in the Lesser Antilles

“…Its last magmatic eruption is estimated to have been 1530 AD Komorowski et al, 2008) and, since then, six phreatic eruptions have occurred: 1690, 1797-1798, 1812, 1836-1837, 1956, and 1976-1977. The last unrest was interpreted as a still-born magmatic eruption by Feuillard et al (1983) (see also Villemant et al, 2005). A renewal of activity started in 1992, and several parameters are currently slowly increasing: intensification of shallow seismicity with long-period events, spatial extension and flux increase of the fumarolic activity at the summit of the volcano, changes in the chemical composition of the gas (sulfur and chlorine), and increases the temperature at several hydrothermal spots.…”

“…The last activity of La Montagne Pelée occurred in 1929 (Romer, 1931), i.e., 27 years after the catastrophic 1902 eruption which killed 29,000 people (Lacroix, 1904). In Guadeloupe, La Soufrière had two phreatic eruptive episodes in 1956 (Jolivet, 1958) and 1976-1977(Le Guern et al, 1980Feuillard et al, 1983), and this later event motivated the evacuation of nearly 73,000 persons during a 6-month period. The Soufrière Hills in Montserrat is presently in a magmatic eruption phase which started in 1995 and has since devastated most of the island (Druitt and Kokelaar, 2002).…”