[15][16], On 5 February 2010, a vulcanian explosion simultaneously propelled pyroclastic flows down several sides of the mountain, and on 11 February 2010, a partial collapse of the lava dome sent large ash clouds over sections of several nearby islands including Guadeloupe and Antigua. L'escalade du volcan est interdite au public mais des points de vue ont été installés à l'Observatoire (MVO) ou sur Jack Boy Hill. Les autres ont migré vers le nord de l'île, dans une zone protégée par la chaîne des Center Hills. Some flows stopped near the edge of Bramble airport; it has remained closed since that time. At 1200 the inflation trend peaked. These surges extended as far E as Paradise Estate, went northward to within 250 m of Windy Hill, inundated the entire village of Streatham, and spread W as far as Gun Hill. MVO staff positioned N of the airport witnessed the front of the flow coming around the bend at Pea Ghaut, just up-slope of Trant's village (figure 24).

Seven zones and six possible alert levels produced 42 different options; a new map could simplify the previous system. The dome's additional bulk furnished less-impeded access to the volcano's N slopes. [4], The Centre Hills in the central part of the island and the Silver Hills in the north are older volcanic massifs related to the subduction zone.[5]. Jimmy Buffett a composé la chanson et l'album du même nom Volcano, en 1979, en référence à la Soufrière, le volcan étant à cette époque inactif. The RSAM peak for the event, which lasted for 30 minutes, indicated shorter but more intense activity relative to the explosion of 17 September 1996. The volcano is flanked by Pleistocene complexes to the north and south. Rockfalls and pyroclastic flows concentrated in Tuitt's Ghaut. 37", "Global Volcanism Program: Eruptive history", "Soufrière Hills volcano, Monserrat (6.2.3. Après la disparition de la capitale, près des deux tiers des 13 000 habitants de Montserrat se sont exilés sur les îles voisines ou au Royaume-Uni. Report on Soufriere Hills (United Kingdom) (Wunderman, R., ed.). Blocks within this lobe were up to 5 m in size and caused widespread destruction to houses in Bethel village. Sur l'ensemble de l'île coexistent environ 700 espèces de plantes indigènes. A small swarm of volcano-tectonic earthquakes also appeared; such earthquakes had been rare in recent months, usually occurring in single swarms. In the eruption's early stages, an EDM/GPS station on the N-flank (at Farrells) moved slowly N, away from the dome complex. The following condenses reports from the Montserrat Volcano Observatory (MVO) and stated sources for the period ending 30 June. The complex, dominantly andesitic Soufrière Hills volcano occupies the southern half of the island of Montserrat. Global Volcanism Program - Soufrière Hills, https://fr.wikipedia.org/w/index.php?title=Soufrière_(Montserrat)&oldid=174965590, Catégorie Commons avec lien local identique sur Wikidata, Portail:Sciences de la Terre et de l'Univers/Articles liés, Portail:Territoires britanniques d'outre-mer/Articles liés, licence Creative Commons attribution, partage dans les mêmes conditions, comment citer les auteurs et mentionner la licence.

Son rôle est aussi l'information du public. The new map in early July (figure 25) contained three zones: the northern, central, and exclusion zones, and only one alert level, "volcanic alert." Limited visibility during June led to the poorly defined, but relatively high extrusion rate of ~3.5 m 3 /s. Figure 27 shows examples of monitored deformation, which includes both Total Station (combined electronic distance measurement (EDM) and theodolite) and global positioning system (GPS) techniques. [13] About 7,000 people, or two-thirds of the population, left Montserrat; 4,000 went to the United Kingdom.[14]. Although N-flank pyroclastic flows became increasingly common during late May-June (figure 23), the most lethal and destructive eruption in the volcano's historical record traveled N on 25 June (figure 24). There was potential for flows to reach much of the S of Montserrat; thus MVO decided that an exclusion zone should include these areas. They also reported a final pulse coming down Paradise Ghaut and surges continuing to spread slowly westward in the Spanish Point area. As the pyroclastic flows emerged from between peaks B and C (figure 23) and progressed into Mosquito Ghaut, fine-grained pyroclastic surges spread laterally onto the ridges on either side.

Deformation studies. Cracks in the crater walls were monitored by frequent measurements between fixed points across them. Beginning of rock falls on dome's N face. https://doi.org/10.5479/si.GVP.BGVN199706-360050. For the first time since 17 June, small pyroclastic flows moved down Mosquito Ghaut; they reached 1 km from the crater rim.

Early August pyroclastic flows destroyed structures in central Plymouth; details will be provided next month.

Subsequent pyroclastic flows increased during early June; during mid-June they reached into Mosquito Ghaut and Gages Valley (figure 23).
Bramble et une nouvelles série d'éruptions entre les 4 et 8 août 1997 a provoqué la destruction de Plymouth, la capitale, qui a été recouverte de cendres à 80 % et définitivement abandonnée[4]. [7] When pyroclastic flows and mudflows began occurring regularly, the capital, Plymouth, was evacuated, and a few weeks later a pyroclastic flow covered the city in several metres of debris. Seismicity overview. The 14 May rockfalls followed about two-and-a-half months of relative stability; by 19 May the intensity of rockfalls increased and they spilled N into Tuitt's Ghaut. During June 1997 MVO published four successive risk maps. The plumes were typically "cigar-shaped" and attached to the source; in GOES-8 satellite imagery they frequently remained discernible 50-100 km W to WNW. Most of these settlements were badly affected or inundated by pyroclastic flows between June and December 1997.

Deflation accompanied by small pyroclastic flows in Mosquito Ghaut, Volcanic tremor; steam and ash production, First pyroclastic flow observed in Mosquito Ghaut from MVO, Loss of seismic signals from eastern stations. Table 22.

Avec l'altitude et l'augmentation de la pluviométrie, on trouve des forêts humides, en particulier le long des crêtes ou des ruisseaux, composées d'arbustes d'une hauteur moyenne de 1,5 mètre. Smithsonian Institution. [12] The riots followed a £10 million aid offer by International Development Secretary Clare Short, prompting the resignation of Bertrand Osborne, then Chief Minister of Montserrat, after allegations of being too pro-British and not demanding a better offer. Deposits and destruction. Although two cycles of lengthening and shortening occurred during 1996, since December 1996 only sustained shortening occurred along certain baselines (Windy Hill and Harris).

Celle du 25 juin 1997 a ravagé l'aéroport W.H. Many of the rock samples collected from the pyroclastic flow into Mosquito Ghaut were moderately vesicular and were therefore interpreted as juvenile (not dome material). This was initially confined by a sector-collapse scar. To announce an evacuation of the central zone the plan included deployment of wailing sirens and maroons (explosive fireworks). Modified from MVO Special Report 03 (29 June 1997). As previously mentioned, the change was accompanied by a short volcano-tectonic earthquake swarm that preceded the hybrid earthquakes. Low amplitude tremor with hybrid earthquakes continued until 1500, at which time the seismicity dropped to background levels.

At 1315 MVO observers flying over the airport found that the initial pulse had overrun the lower parts of local settlements (Harris, Farm, and Trant's), and came to within 50 m of the sea. Strong deflation on tiltmeters preceded a dome collapse at 2330; pyroclastic flows traveled 2 km down Gages Valley (200 m further than previous ones) and 3.5 km down Mosquito Ghaut. La partie sud de l'île, y compris l'ancien aéroport, a par ailleurs été complètement dévastée, recouverte par une épaisse couche de lave et de boue.

The event left a steeply-dipping, circular scar ~200 m across in the dome's NNW face.

L'Office du Tourisme a par ailleurs développé une partie de sa communication autour du volcan[8]. Le bas de la Soufrière est couvert de broussailles sèches et de fourrés. The island's airport was directly in the path of the main pyroclastic flow and was completely destroyed.

Eruption of 25 June. Within a given swarm, the earthquakes generally had similar magnitudes and the few larger earthquakes were of relatively small magnitude; much larger ones had been recorded previously. [11], The governments of the United Kingdom and Montserrat led the aid effort, including a £41 million package provided to the Montserrat population; however, riots followed as the people protested that the British Government was not doing enough to aid relief.

Therefore, a central zone was designated in which people should be on increased alert. Le second est situé au centre de l'île, à Center Hills (740 m), et, enfin, la Soufrière est le volcan actif, occupant toute la moitié sud.

Une de ses éruptions a dévasté, en 1997, la capitale, Plymouth, devenue aujourd'hui une ville fantôme. Where unspecified, pyroclastic flow runout distances are measured from the crater. Following the 25 June pyroclastic flows, the inflation-deflation cycle continued with the same period and amplitude that began 22 June. Pyroclastic flow in Tuitt's Ghaut travels 1.4 km. The surge into Dyer's Ghaut and the Belham River valley was remarkable in that a relatively fine-grained flow traveled a significant distance off the main flow path. 6 (June 1997)

Table 21. The number of hybrid earthquakes varied in-phase with the inflation-deflation cycle (i.e. Montserrat appartient à un arc volcanique d'îles à la j…

L'éruption du 25 juin 1997 a provoqué la mort de 19 personnes. La dernière modification de cette page a été faite le 23 septembre 2020 à 14:10. Risk map. Pyroclastic flow material advanced 500 m down Mosquito Ghaut.

The number of these earthquakes remained low, not exceeding 40/day, and returned to normal levels after 13 June. Please cite this report as: Deposits along the whole length of the Belham valley were fine-grained with a near absence of coarse blocks. This event marked the beginning of inflation-deflation cycles with periods shortened to 8 hours and amplitudes increased to ~40 µrad.

Many Montserrat residents remain despite these dangers because volcanoes produce good soil for farming and even spectacular views for those willing to brave the risks. Between 22 and 25 June MVO noted seven hybrid swarms; both the duration and number of component events in these swarms increased (figure 26). Earthquakes were of moderate amplitude; they caused saturations on the Gages and Windy Hill drum records. Il est en activité depuis le 25 juin 1995. Pyroclastic flow in Tuitt's Ghaut travels 2.9 km, 250 m from intersection with the Paradise River.

A catastrophic eruption in 1997 forced an evacuation of part of the island and destroyed the capital city of Plymouth.
Pyroclastic flow down Tuitt's Ghaut travels 1 km from the crater. The line across the island's center was controlled primarily by topography.