March 26 , 2016. EN. Momotombo , Yellowstone , Zhupanovsky , Popocatepetl .

Home / blog georges Vitton / March 26 , 2016. EN. Momotombo , Yellowstone , Zhupanovsky , Popocatepetl .

March 26 , 2016. EN. Momotombo , Yellowstone , Zhupanovsky , Popocatepetl .

March 26 , 2016.

 

Momotombo, Nicaragua :

 

Reported rumblings and explosions in the Momotombo Volcano, without major incidents

24 MARCH 2016 The Momotombo Volcano registered explosions at approximately 6:57 pm on Thursday-night.

Communicating through Tu Nueva Radio Ya, Comrade Armando Saballos, from INETER Volcanology, said the Momotombo spewed ash between 1000 and 2000 meters high with incandescent material, a product of this new episode of eruptive process which started last December.
The specialist said that these new explosions are within the normal parameters of the activity of the volcano, which awoke on December 1, 2015 after 110 years of dormancy.

 

momotombo

 

Saballos explained that the Momotombo volcano spent about 4 days in relative calm without experiencing explosions, but « in the last 24 hours the volcano has increased its volcanic tremor, which is part of the eruptive process that this volcano has presented since December last year. This volcanic tremor shows that there has been a slight increase in the activity of the volcano and tonight at 6:57 began to experience some explosions with ash outlet, gases and incandescent material deposited on the slopes of the volcano « , he said.

« Some explosions produce an audible signal that nearby villagers heard as thunders. That’s something completely normal in the volcano, we already have experienced this since December, but this year the volcano’s activity has been lower than what we experienced in the first week of December last year, « he added.

 

Momotobo

 

The expert said the activity at the volcano is normal and therefore the population should not be alarmed. « Everything is under the parameters which we have we communicated to the population above and all our surveillance system is on. Everything is under control, so we are communicating to the public this information so that we are calm, there is nothing out of the normal in this volcano, « he said.

Saballos recalled that the entire emergency system that emerges from the SINAPRED remains active to any incident.

« We have been monitoring and reporting every day, although we are at Easter we are always working, our government never rests for ensuring the safety of our people, » said Saballos.

Source :   EL 19 DIGITAL .

Photo : La prensa ,  Photovolcanica

 

Yellowstone , United- States :

I reproduce here « in extenso » a wonderful article from Claude Granpey published on its website: http://claudegrandpeyvolcansetglaciers.com

Up to now, the common theory about the origins of Yellowstone was that the so-called supervolcano was born from a hotspot, in other words a mantle plume emerging from our planet’s core. But a new simulation shows that the conventional hypothesis was wrong. The plume could not have reached the surface because it was blocked by a slab from an ancient tectonic plate.
The simulation results of the model, which is the first to replicate the complex interaction between a mantle plume and a sinking slab, were detailed last month in Geophysical Research Letters.

 

Afficher l'image d'origine
Geologists at the University of Illinois built the model to replicate both the plate tectonic history of the surface and the geophysical image of Earth’s interior. Not only did the researchers create a three-dimensional view of Yellowstone’s interior, they did so over the past 40 million years in an attempt to re-create the eruptions that have dotted the U.S. from Oregon to Wyoming. However, they found it impossible to re-create most of the recent eruptions because of the presence of a slab which was driven deep into Earth’s mantle about 100 million years ago when the Pacific and North American plates began converging.
According to the scientists, the mantle flowed around the sinking slab causing pressure to build toward the front. Their model shows that 15 million years ago the pressure difference became too much to bear and the slab began to tear. The plume below pulsed through the slab, leading to massive outpourings of magma which appear consistent with the Steens–Columbia River flood basalts.

 

yellowstone
Despite the gaping hole in the center of the sunken slab, the plume did not continue to rise through it because the mantle is highly viscous. So as the slab continued to sink, it pulled the surrounding mantle down with it, ultimately sealing the hole and blocking the plume from reaching the surface for the next 15 million years.
The favoured hypothesis cannot explain the string of volcanic eruptions since those first flood basalts, including the formation of Yellowstone’s caldera, which happened only 2.1 million years ago. As a consequence, a new explanation for Yellowstone’s formation needs to be found, as well as an additional heat source for Yellowstone! One researcher thinks this could come from the Juan de Fuca Ridge in the Pacific Ocean. Although that’s almost 1,600 kilometers away from Yellowstone’s hotspot today, the ridge can easily affect the middle of the North American Plate. Because it lies just slightly west of the Cascadia subduction zone, the young seafloor is easily shoveled east beneath the North American Plate. So it is likely that some event, millions of years ago, spurred a lot of heat within the Juan de Fuca Plate, which was then shoveled underneath the North American Plate and swept along with that string of volcanic eruptions until it eventually helped form Yellowstone’s gaping caldera in the Rocky Mountains.
Whatever the origin of Yellowstone’s volcanism, the model makes it clear that slabs are much more important than previously thought.

Sources: C Granpey , Scientific American: http://www.scientificamerican.com/

Photos : Geo , maxisciences.com .

 

Zhupanovsky, Kamchatka :

53.59 N, 159.15 E;
Elevation 9702 ft (2958 m)
Aviation Color Code is ORANGE

A moderate activity of the volcano continues. Ash explosions up to 19,700-26,240 ft (6-8 km) a.s.l. could occur at any time. Ongoing activity could affect international and low-flying aircraft.

A moderate activity of the volcano continues. According to Tokyo VAAC data, an explosion sent ash up to 8 km a.s.l. at 1320 UTC on 24 March. Satellite data by KVERT showed an ash cloud in size 8×10 km drifted on the height 3.5-4.0 km a.s.l. for about 134 km to the north-west from the volcano on 24 March. The volcano was quiet or obscured by clouds in the other days of week.

 

zhupanovsky

The Zhupanovsky volcanic massif consists of four overlapping stratovolcanoes along a WNW-trending ridge. The elongated volcanic complex was constructed within a Pliocene-early Pleistocene caldera whose rim is exposed only on the eastern side. Three of the stratovolcanoes were built during the Pleistocene, the fourth is Holocene in age and was the source of all of Zhupanovsky’s historical eruptions. An early Holocene stage of frequent moderate and weak eruptions from 7000 to 5000 years before present (BP) was succeeded by a period of infrequent larger eruptions that produced pyroclastic flows. The last major eruption took place about 800-900 years BP. Historical eruptions have consisted of relatively minor explosions from the third cone.

Sources : Kvert , Gvp .

Photo : A. Sokorenko, IVS FEB RAS 20/1/2015

 

Popocatepetl , Mexico :

March 25, 11:00 h (March 25, 17:00 GMT)

In the last 24 hours 6 low-intensity exhalations were recorded through the surveillance system at Popocatépetl volcano. Also, at 00:26 h, a small explosion was observed; the ash emission reached 500 m above the crater, being displaced towards northeast, and some incandescent fragments were thrown to a distance of about 400 m on the north face.

Although sometimes we had partial visibility due to clouds, a continuous steam and gas emission was observed .

 

CENAPRED emphasizes that people SHOULD NOT go near the volcano, especially near the crater, due to the hazard caused by ballistic fragments.

This type of activity is included within the scenarios Volcanic Traffic Light Yellow Phase 2.

Source : Cenapred .

Photo : Volcán Popocatépetl e Iztaccíhuatl

 

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