16/05/2015. Etna , Piton de la Fournaise , Kilauea.
Etna, Sicile :
The eruption of Etna touch it to an end? This morning, the tremor is falling (it had already started to decline yesterday)
The flow apparently always powered is arrived in Valle del Bove just upstream of the Rocca Musarra at about 1800 meters above sea level, perhaps less.
An abundant ash emission took place this morning. The wind pushed them north, still closing Reggio Calabria airport.
Photos : Turi Caggegi.
Piton de la Fournaise , La Réunion :
Activity report – highlights between May 4 and May 12, 2015
Since 4 May (date of the last bulletin), the Volcanological Observatory of Piton de la Fournaise recorded
123 volcano-tectonic earthquakes summital (12.5 per day)
67 volcano-tectonic earthquakes deep summital (directly above the top under the sea level)
244 landslides in the crater Dolomieu
7 local earthquakes (deep under or near the island)
4 earthquakes TV (Including Nepal)
Cratère Bory, piton de la Fournaise © OVPF
The uppermost volcano-tectonic earthquakes were located directly above the summit of the Piton de la Fournaise, between 500 below the sea level and 500 m above the level of the sea. Their magnitudes are relatively low outside 4 events whose magnitude exceeds 2.
Note that the number and magnitude of earthquakes increase over days and 57 summital volcano-tectonic earthquakes were recorded in a single day, May 12 At 1:04 (local time) in the morning an earthquake measuring 2.7 located below the summit was felt by the campers at Nez Coupe du Tremblet.
Figure 1: Number of volcano-tectonic earthquakes during the period from 4 to 12 May 2015
The deformation at the base of the summit cone (about 2000m above sea level) continues with a clear trend towards inflation. At the top, the inflation rate has slowed.
Figure 2: Average speed (mm / year) of deformations measured on the last 60 days.
SO2 emissions after the peak of May 3, lower concentrations are detected
H2S: confirmation and acceleration of the trend of increasing
CO2: increasing trend at the top while the flow is stable to high values ??regarding the measurements made on the Plains
Remarks:The increase in emissions of H2S detected at the fumaroles of the summit of the Piton de la Fournaise since mid-March is confirmed and found a further acceleration since May 5, that is to say immediately after a spike in SO2 emissions observed on May 3In the same period a new CO2 enrichment is observed these apical emissions with moderate increasing trend reports CO2 / H2O, CO2 / H2S and CO2 / SO2.These trends may suggest increase in transfer of magmatic fluids to more superficial levels.
Figure 3: Evolution of the fumarolic gas composition at the summit of Piton de la Fournaise since the eruption of February 2015
Source : OVPF
Kilauea, Hawai :
19 ° 25’16 “N 155 ° 17’13” W,
Summit Elevation 4091 ft (1247 m)
Current Volcano Alert Level: WATCH
Current Aviation Color Code: ORANGE
KILAUEA INFORMATION STATEMENT
Activity at the summit of Kilauea Volcano continues to change, as shown by a pronounced drop in the level of the lava lake within Halema’uma’u Crater, a change in the summit area deformation pattern, and the concentrated earthquake activity in the southern part of the caldera and upper Southwest Rift Zone. This statement reviews recent observations and briefly summarizes what might be expected next at Kilauea.
DROP IN LAVA LAKE LEVEL WITHIN HALEMA’UMA’U CRATER AND SUMMIT ACTIVITY CHANGES
The lava lake in the Overlook crater (summit vent) overflowed its rim beginning April 28, sending many short flows across the floor of Halema’uma’u Crater. By May 8, these overflows and spatter from the rising lava lake had built a ridge (or levee) of solidified lava around the vent rim to a height of about 8 m (26 ft) above the floor of Halema’uma’u Crater, creating a “perched lava lake.” On May 9, the lava lake level began to drop, and, as of this morning (May 15), the lake surface was about 50 m (165 ft) lower than the newly created vent rim.
Kilauea Volcano’s summit lava lake continued to drop today (May 15, 2015). Measurements of the lake surface late this afternoon showed that it was 62 m (203 ft) below the top of the newly-created vent rim, a ridge (or levee) of solidified lava about 8 m (26 ft) thick that accumulated on top of the Halema’uma’u Crater floor from multiple overflows of the vent during the past two weeks.
The abrupt lowering of the lava lake level was accompanied by changes in summit deformation and seismicity. As the lava lake dropped, the inflationary trend previously observed in the summit area changed to a deflationary trend centered near Halema’uma’u Crater. On May 13, the focus of deformation changed to the southern part of Kilauea’s summit caldera and upper Southwest Rift Zone, where rapid and localized inflationary tilt was recorded.
This change in deformation was accompanied by a shift in the focus of earthquake activity from Kilauea’s summit, upper East Rift Zone (ERZ), and upper Southwest Rift Zone (SWRZ) to the southern part of Kilauea’s caldera and Upper SWRZ. Of the many hundreds of earthquakes that have occurred in the SWRZ over the past 2 days, most have been small (less than magnitude-2) and shallow (less than 4 km [2.5 mi] deep). As of noon on May 15, earthquakes over the past 12 hours were occurring every couple of minutes, the highest rate recorded thus far, including this morning’s magnitude-3.2 quake at 08:37 a.m., HST, and magnitude-3.0 quake at 10:52 a.m., HST.
HVO webcams captured a short-lived dusty-brown plume generated by a small rock fall from the summit vent wall at 3:24 p.m., HST, this afternoon (May 15, 2015).
During this period of elevated summit activity, there has been no obvious change in the eruption rate of lava from the Pu’u ‘O’o vent on Kilauea’s East Rift Zone. Few earthquakes have occurred in the upper ERZ over the past few days.
WHAT WE CAN EXPECT
These recent changes at the summit of Kilauea suggest that magma has moved into a shallow area beneath the southern part of the caldera and upper Southwest Rift Zone.
It is not possible to predict the exact outcome of this activity, but we identify three possible scenarios that could play out in the coming days to weeks:
1. Magma continues to accumulate in the southern part of Kilauea’s summit caldera and upper SWRZ at shallow depths, but then stops with no eruption.
2. Magma continues to accumulate in the southern part of the caldera at shallow depths and leads to a rapid intrusion into the Southwest Rift Zone. Such an intrusion could remain within the rift zone or erupt along the rift zone. A rift zone intrusion would be indicated by a swarm of shallow earthquakes, seismic tremor, and large, rapid changes in the deformation of the ground surface.
3. Magma continues to accumulate in the southern part of the caldera, rises toward the surface, and erupts in the upper SWRZ and/or in the caldera. With this scenario, we would expect to see even stronger earthquake activity and/or seismic tremor in the southern part of the caldera, as well as ground cracks.
The east rift zone is the largest structure on Kilauea. It forms a broad ridge several kilometers wide at its crest and extends 130 km from the summit caldera to the ocean floor! Lava flows erupted from the rift zone spread both to north and south; on land, the flows spread primarily southward. A wide variety of volcanic features highlights its crest—cinder and spatter cones, lava shields and pit craters, fissures, ground cracks, and faults. On land, the east rift zone is loosely divided into three segments—the upper, middle, and lower segments. Beneath the sea, the east rift zone is known as the Puna Ridge
However, the overall evolution of unrest in Kilauea’s summit area and upper rift zones in the coming weeks to months is uncertain. The magma storage system within Kilauea is highly pressurized at this time, and future changes in the location of unrest—and the potential for eruption—could unfold quickly (in days to hours).
Source : HVO