July 13 , 2018. EN. La Réunion : Piton de la Fournaise , Hawai : Kilauea , Ecuador / Galapagos : Sierra Negra , Vanuatu : Ambrym .

Home / Ambrym / July 13 , 2018. EN. La Réunion : Piton de la Fournaise , Hawai : Kilauea , Ecuador / Galapagos : Sierra Negra , Vanuatu : Ambrym .

July 13 , 2018. EN. La Réunion : Piton de la Fournaise , Hawai : Kilauea , Ecuador / Galapagos : Sierra Negra , Vanuatu : Ambrym .

July 13 , 2018.

 

La Réunion , Piton de la Fournaise :

Activity Bulletin from Friday, July 13, 2018 at 00:00 (local time)

Since 23:40 local time (July 12), a sharp increase in seismicity is observed. And since midnight a seismic crisis is recorded on the instruments of the Volcanological Observatory of Piton de la Fournaise. This seismic crisis is accompanied by rapid deformation, This indicates that the magma is leaving the magma reservoir and is spreading to the surface. An eruption is likely in the near future in the next minutes or hours.

Alert Level: Alert 1

Activity Bulletin from Friday, July 13, 2018 at 05:00 AM (local time)

Following the seismic crisis that started shortly before midnight on July 12th, the volcanic tremor, synonymous with the arrival of magma near the surface, appeared very gradually on the OVPF’s seismic recordings since about 03:30 local time on July 13th. According to OVPF records, the source of this tremor is located on the northern flank of the volcano.
The first rays of eruption appeared on the OVPF webcams at 4.30 am (local time).

Alert Level: Alert 2-2: Eruption in the Enclos .

Piton de la Fournaise: passage on alert 2-2 eruption in progress in the Enclos .

The prefect of Reunion triggered this day at 4:30, alert 2-2 of the plan « ORSEC * Volcano »: eruption in progress.

Les Premiers Instants De La Troisième Éruption De L'année 2018Vidéo De ©Imaz Press Réunion (Page officielle)

Publiée par Piton De La Fournaise sur Jeudi 12 juillet 2018

Public access to the upper part of the Fouqué enclosure, whether from the Pas de Bellecombe Trail or from any other path, as well as landing aircraft in the volcano area, are prohibited until further notice. opinion. The Sainte-Rose Coupé Nose Trail is currently closed to pedestrian traffic from the Piton Partage because of a real and impending danger of collapse.
Any significant change will be the subject of a new communication.

Activity Bulletin from Friday, July 13, 2018 at 10:30 am (local time)

Following the overflight of the eruptive site realized this morning with the help of the Air Section of Gendarmerie and the PGHM, the eruptive site could be located with precision. It is located on the north side of the volcano.
A total of 4 eruptive fissures were opened over 1 km in length, spreading from upstream of Rosemont Chapel towards Formica Leo (Figure 1).

Figure 1: Location of both ends of the eruptive site. In total there are 4 cracks that opened between these two points. (© OVPF / IPGP)

At 08:00 (local time), the 4 cracks were still active with projection heights not exceeding 20 m high. The flows aa that flowed were spread over distances of the order of 200 m (Figures 2).


Figure 2: Shooting of the eruptive site this morning around 8am, local time (© OVPF / IPGP)


Figure 3: Shooting of the eruptive site this morning around 8am, local time (© OVPF / IPGP)


Figure 4: Shooting of the eruptive site this morning around 8am, local time (© OVPF / IPGP)

Alert level: Alert 2-2: Eruption in the Enclos.

Source : OVPF

Photos :  Brieuc Coessens Studio .

Video : Imaz press reunion

 

Hawai , Kilauea :

Thursday, July 12, 2018, 10:51 AM HST (Thursday, July 12, 2018, 20:51 UTC)

19°25’16 » N 155°17’13 » W,
Summit Elevation 4091 ft (1247 m)
Current Volcano Alert Level: WARNING
Current Aviation Color Code: ORANGE

Kīlauea Volcano Lower East Rift Zone

Fissure 8 continues to erupt lava into the perched channel leading northeastward from the vent. Lava levels in the upper channel between Fissure 8 and Pohoiki Rd. are low this morning but are expected to rise after the next collapse/explosive vent at Kīlauea summit. Overnight, the diverted channelized ʻaʻā flow west of Kapoho Crater advanced to the ocean destroying the Kua O Ka La Charter School and Ahalanui Count Beach Park and establishing a robust ocean entry. Despite no visible surface connection to the Fissure 8 channel, lava continues to ooze out at several points on the 6 km (3.7 mi) wide flow front into the ocean.

Fissure 22 has no visible activity. No other fissures are active.

Kīlauea Volcano Summit

Earthquakes in the summit area have resumed following yesterday’s collapse/explosion event at 5:46 AM HST, which had an energy equivalent to a magnitude-5.3 earthquake. The current rate of earthquakes ranges from 20-35/hr and is expected to continue as has been the pattern leading up to a collapse/explosion event, which is expected to occur later today. Inward slumping of the rim and walls of Halemaʻumaʻu continues in response to the ongoing subsidence at the summit.

Source : HVO

Photo : Bruce Omori.

 

Ecuador / Galapagos , Sierra Negra : 

Thursday, July 12, 2018 09:42 Sierra Negro Volcano Terrain Report, June 27-28, 2018
Thermography, mapping and sampling of new lava flows, Chico Volcano area.

Summary:
On 27 and 28 June 2018, a group of scientists from the Institute of Geophysics of the National Polytechnic School (IGEPN), taking advantage of a logistic flight (Latacunga – Puerto Villamil – Quito) managed by the Department of Management Risks, approached the region of Chico volcano, on the Sierra Negra volcano (Isabela Island, Galapagos), to carry out a field work on the deposits of the eruption of March 26th. The work was carried out with the authorization and support of the Galapagos National Park. The night of the 27th was a first approach to the active zone with thermal imaging of eruptive fissures and deposition of lava flows. On the morning of the 28th, a second approach was made to complete the thermal images with direct thermocouple measurements and sampling of eruptive products (slags, bombs and volcanic lava), and taking pictures with drone for mapping. The lava fields were still very hot with temperatures up to 975 ° C.

In addition, it has been observed that lava fields were particularly unstable with many lava tunnels collapsed or collapsing. Eruptive products are typical of basaltic eruptions with slag, Pelee hair and volcanic bombs (splashing) around eruptive fissures, Pahoehoe and AA lava deposits on the northern flank of the volcano and within the caldera. At the request of the Minister of Government of the Special Galapagos Regime Board, the Secretary of Risk Management, and the PNG Directorate, IGEPN staff attended the WCC meeting during which information about the activity status of the volcano and provided advice on the subject to the authorities and the community. In conclusion, it is not recommended to approach the lava fields because of the presence of gas, high temperatures and the danger of collapse of lava tunnels.

Figure 1. Lava fields of Sierra Negra volcano, Chico Volcano area (photo: Benjamin Bernard, IGEPN).

1. Thermal monitoring

1.1. Infrared images
On the night of June 27, it was possible to reach the site where the antennas of the IGEPN monitoring stations are located, on the edge of the caldera and with the use of an infrared camera, it was possible to observe the crack on the Chico volcano, from where several lava flows were emitted on June 26, identifiable by its high temperature (figure 2). Most of the lava flowed out of the caldera towards the north flank, where several deposits of castings were observed to descend to Elizabeth Bay (Figure 2). A small flow descended into the caldera from the same crack (Figure 2) and showed no mobility.

Figure 2: Composition of thermal images showing the lava flows that were emitted from the crack on the Chico volcano, towards the outer edge North (right) and towards the inside of the caldera (on the left) (thermal images : Silvia Vallejo, IGEPN).

Given the extent and temperature of these lava flows, it was not possible to continue to observe and obtain thermal images of the flows from other cracks to the northwest of this last position.

1.2. Direct measures
The temperature measurements were made using an IR camera and a thermocouple. Temperatures were taken from the crack zone and down the edge of the easternmost lava flow and forward of a small lobe formed by this flow.
In the area of ​​the crack from which the lavas originate, apparent maximum temperatures (TMA) of 580 ° C were observed in one of the cracks. Mean lava flow surface temperatures were generally around 60 ° C, but could reach temperatures of around 200 ° C. Below the surface, the temperature reached higher values. The maximum measured temperature was TMA = 975 ° C, in a crack in the lava flow that had been stopped by pre-existing lava (Fig. 3).

Figure 3. The image on the right shows where the temperature is highest in the lava flow; on the left, the thermal image of the site with the measured temperature (left picture: Francisco Vásconez, the thermal image: Silvia Vallejo, IGEPN).

Measurements made with the thermocouple in the vicinity of the crack showed temperatures of 485 ° C in a crack, while in the slag deposits and neighboring projections, temperatures of 284 ° C were measured. In a crack in the casting, a temperature of 585 ° C was measured. Similarly, inside a Pahoehoe lava flow a temperature of 724 ° C was measured (Figure 4A).

2. Cartography
A series of aerial photographs was made using a drone, flying at ~ 60 m above the level of the crack and lava deposits. We obtained an orthophoto and a digital surface model with a resolution of ~ 3 cm / px. You can clearly see the eruptive crack, the different types of lava flows and also the lava tunnels. The visible cracks are slightly arched with a general direction ENE, as the cracks of 1979 and 2005 in the region of Chico Volcano. The largest is more than 150 m long. In this area, lava flows reach up to 130 m wide in flat areas, but only 25 to 35 m when channeled. In flat areas they resemble a Pahoehoe lava (smooth surface, sometimes roped texture and lava tunnels) while in channelized zones with a higher slope they have an AA lava appearance (rough surface with natural levees). In general, the edges of the castings have a thickness of 0.5 to 1 m and in many places lava has filled cracks or depressions earlier.

Figure 4. General Map (Benjamin Bernard, IGEPN). The maps are projected in the Universal Transverse Mercator (UTM) coordinate system, Zone 15S, WGS84.

3. Sampling
Samples of slag and volcanic bombs were collected near the cracks and lava blocks in the Pahoehoe lava fields (Figure 5). Due to the weather, the AA lava flows were not accessible. All samples are almost afanitic (no magnifying crystals) with high iridescence, are usually vesiculated and have fluid textures indicating high gas content and low viscosity. All samples have an apparent basaltic composition, however, it is necessary to make a chemical analysis to determine their composition.

Figure 5. Sampling of rock material in a lava flow and temperature measurement with thermocouple and thermal imaging camera (photo: Patricio Ramón, IGEPN).

Source : BB, PR, SV, FJV , Institut de géophysique , École nationale polytechnique.

 

Vanuatu , Ambrym :

VANUATU VOLCANO ALERT BULLETIN N°5 – AMBRYM ACTIVITY , Wednesday July 11th 2018

16°15’00”S 168°07’00”E
Summit Elevation 4377ft (1334m)
Current Vanuatu Volcano Alert Level: Level 2

Ambrym volcano is continuing in the major unrest state. The Volcanic Alert Level remains at Level 2 .

The volcanic unrest continues at Ambrym. The volcanic activity is likely to continue at similar levels, consistent with Volcanic Alert Level 2. The Danger Zone for life safety is limited at the Permanent Exclusion Zone at Benbow which is about 1 km around Benbow crater and the Danger Zone A at Marum (including Maben-Mbwelesu, Niri-Mbwelesu and Mbwelesu) which is about 2.7 km around Marum crater

Observations in June 2018 confirm that the activity is confined in Benbow and Marum craters. The activity consists of ongoing lava lake activity inside the active vents inducing sustained substantial degassing and emission of steam cloud. Gas will be continue to be smelt while approaching the volcanic area and craters.

These observations and the analysis of seismic data confirm that the unrest level of volcano activity is continuing.

Alert Level for Ambrym volcano has been at the Level 2 since 7 December 2017. The current observations are consistent with the Alert Level 2 activity. Level 2 indicates ‘Major Unrest; Danger Zone is at 1 km around Benbow crater and 2.7 km around Marum’ .

Ambrym volcano is a very active volcano in Vanuatu with large caldera of 12 km diameter and 2 active craters Marum and Benbow. The volcano has been active during historical time at both summit and flank vents, producing moderate explosive eruptions and lava flows that have reached the coast. The larger events include eruptions in 1820, 1894, 1913 or 1929. Over the last seventy years, there are no extra-caldera eruptions. The eruption of 2015 is focused in the caldera.

Source : Geohazard Vanuatu.

Photo : G Vitton

 

Recommended Posts

Leave a Comment

Nous contacter

Nous ne sommes pas disponibles pour le moment. Mais vous pouvez nous envoyer un email a l'aide du formulaire ci-dessous.

Not readable? Change text. captcha txt

Start typing and press Enter to search