GLOBAL VOLCANISM: Third Day Of Volcanic Tremors At The Kirishima Volcano - Japan Meteorological Agency Warns Of "CATASTROPHIC ERUPTION"! [VIDEOS]

Kirishima of southern Kyushu have one after another volcanic tremors that indicates the movement, such as magma underground,
Meteorological Observatory, it has urged to be aware of the catastrophic blowout phenomenon.

February 10, 2016 - JAPAN - In the vicinity of the Iozan of Ebino Kirishima mountain range that spans Miyazaki Prefecture and Kagoshima Prefecture, on the 10th early in the morning, volcanic tremor that becomes the third time earlier this month has been observed.

With performing the Japan Meteorological Agency is again field survey, we urged to be aware of the catastrophic blowout, such as fumaroles and volcanic gas as volcanic activity has been slightly increased.

And depends on the Japan Meteorological Agency, in the vicinity of the Iozan of the Kirishima mountain range, from before 5:00 on the 10th morning, a small volcanic tremor amplitude is considered to indicate the movement of the hot water and volcanic gas underground has been observed over a period of approximately 2 minutes .


WATCH: Volcanic tremors at Kirishima volcano.

Also, in addition to changes in the small ground with the tremor was observed, volcanic earthquakes have been observed four times up to 6 am and the front and rear of the fine.

The volcanic tremor was observed in the vicinity of the Iozan, is the third time this time following the month 7th and 8th.

For this reason, the Japan Meteorological Agency 10 morning, have carried out a dispatch to investigate the two officials again to local, state and of the fumaroles that up from, such as in the crater, the temperature of the ground in the vicinity of the jet is not spread high range we have examined and whether.

In Iozan now, other than the interval of approximately 30 meters mountain trail through the directly in front of the jet has not been carried out, such as intrusiveness regulation, Miyazaki Prefecture, such as the 10th afternoon, to consider the expansion of regulation to open the conference to have.

Location of the volcano. Google Maps

Kirishima (新燃岳 in Japanese), one of Japan's most active volcanoes. It is actually a group of 18 young, small stratovolcanoes north of Kagoshima Bay: Takachihonomine, Nakadake, Ohatayama, Karakunidake, Tairoike, Ohachi, and Shinmoedake are the principal vents.

Historic eruptions have been recorded since 742 and there are more than 60 recorded eruptions, mainly from Ohachi and Shinmoedake, with the exception of a small lava flow from Iwoyama in 1768. Relatively large eruptions occurred in 788, 1235, 1716-17 and 1768, and in 2011.

A violent eruption started at Kirishima on January 26, 2011, the largest one for more than 50 years.

Background:

The large Kirishima volcanic group covers an NW-SE elongated area of about 20 x 30 km. The late-Pleistocene to Holocene volcanoes are dominantly andesitic in composition and consist of stratovolcanoes, conder cones, maars overlying shield volcanoes. The larger edifices are the centrally located, 1700-m-high stratovolcanoes Karakuni-dake, and the large maars Onami-ike and Mi-ike, located SW of Karakuni-dake. Eruptions in the past 10,000 years have been concentrated along an E-W line of vents from Mi-ike to Ohachi, and at Shinmoe-dake to the NE. Frequent small-to-moderate explosive eruptions have been recorded since the 8th century. Fumaroles are located on North slope of the Karakunidake.

Eruptive history of Kirishima volcano
By most authors, the "Kirishima volcano" is referred to those volcanic edifices overlying (younger than) the Kakuto ignimbrite, related to the Pleistocene Kakuto caldera that formed around 300,000 years ago.

A series of stratovolcanoes, now poorly preserved, grew in the early stage of activity following the Kakuto caldera formation. An interval of volcanic quiet followed until about 60-70,000 years ago, when the present-day stratovolcanoes which make up the Kirishima complex started to grow.

About 35,000 years ago, a major eruption triggered the collapse of Hinamoridake volcano at the northeastern end of the complex. It produced a major debris avalanche that covers the area of present-day Kobayashi City.

22,000 - 18,000 years ago, Iimoiyama and Maruokayama stratovolcanoes and a number of smaller edifices formed.

18,000 years ago, the Old-Karakunidake, Koshikidake and Shinmoedake volcanoes grew.

15,000 years ago, a large eruption built present-day Karakunidake volcano, by rapid accumulation and welding of pyroclastic fall and flow deposits draped over the older cone. Shortly later, lava flows erupted from a vent on the southeast flank of Shinmoedake, building Nakadake.

9000 years ago, Shinmoedake had a larger explosive eruption.

7000 years ago, Old-Takachiho volcano formed from a vent on the southeastern area of Kirishima. Other monogenetic volcanoes that probably formed about that time include Ohataike and Biwaike maar.

6300 years ago, a major eruption from Old-Takachiho volcano occurred and built up the main cone present today.

The next 1000 years, only minor activity if any took place.

About 5000 years ago, Takachiho-no-mine stratovolcano formed on the western slope of Old-Takachiho.

Small lava flows erupted from Fudoike and Ohatayama.

4000 years ago, Shinmoedake had another larger explosive eruption.

The Miike maar formed 3000 years ago, following a powerful explosion that ejected a large pumice deposit and produced base surges.

Only about 1000 years ago, Ohachi volcano formed on the western slope of Takachiho-no-mine and has remained the most active vent of Kirishima volcano since then.

Explosive eruptions from Kirishima volcano
During the past 22,000 years, volcanic activity was concentrated in a zone running NW-SE and in the past 10,000 years mainly from Takachiho volcano in the southeastern part of the Kirishima complex. Kirishima's activity during the past 22,000 years comprises a number of large explosive (vulcanian to subplinian) eruptions that have left important tephra layers, including:

- Karakunidake scoria (ca. 18,000 years ago)
- Kamamuta scoria (ca. 7000 years ago)
- Ushinosune ash (ca. 6500 years ago)
- Miikee pumice (ca. 3000 years ago)
- Araso tephra ca. 700 AD
- Katazoe tephra 788 AD. This eruption was studied by Miyamoto (2005) as an example of a case where 3 types of magma were erupted: basalt, basaltic-andesite and andesite.
- Miyasugi tephra (ca. 1000 AD): several scoria layers from powerful vulcanian-type eruptions, similar to the recent 2011 eruption. They occurred in historic time, but the exact date is unknown.
- Takaharu tephra (ThT) in 1235 AD, the largest tephra layer from an eruption in historic time (subplinian eruption, ca. 0.3 cubic km of ash and pumice)
- Shinmoedake-Kyoho pumice 1716-1717 AD
- Shinmoedake-SHowa ash 1959 AD

Ohachi volcano
Ohachi Volcano is the youngest and most active of the Kirishima group of stratovolcanoes, located at the southeastern part of the group.

It has a considerably large crater compared to the size of the cone, with thick layers of welded scoria visible in the crater walls.

The oldest tephra recognized from Ohachi Volcano is the Araso tephra (AsT), which erupted around 700 AD, thus suggesting that Ohachi is little over 1300 years old.

Ohachi's rate of activity was not constant throughout its history. In its early stage from AD 700 to 1235, 80% of its present-day volume was erupted.

The magma chamber of Ohachi volcano has been estimated to be shallow, at around 4-6 km (ca. 1-2 kbar lithostatic pressure).

Magma discharge rates from Kirishima volcano
Based on magma discharge, the past 22,000 year interval of volcanic activity at Kirishima can be divided in 3 phases:

22,000 - 15,000 years ago: 0.8 million m3 / year

15,000 - 7,000 years ago: a relatively quiet period with only 0.04 m3 average magma output /year

7,000 years ago - present: 0.5 million m3 / year

In total, Kirishima volcano has erupted about 10-15 cubic kilometers of magma during the past 22,000 years. In the earlier period from 22-15,000 years ago, 5 stratovolcanoes, and 2 smaller cones were formed. The eruptions were dominantly effusive (lava flows).

Following an 8000 year long interval with much less activity, the rate of eruptions increased again. Activity in the recent epoch has been more explosive and concentrated in the southeastern part of the complex.

Geothermal activity
The Kirishima volcanic area contains various thermal waters. Hydrogen sulfide springs, acidic sulfate springs and chloride springs are found in geographically narrow zone. Bicarbonate springs are distributed in the Shinkawa ravine in the southwestern periphery of the Kirishima volcanic area and the Hinatayama-Himegi region, both of which are on the southwestern periphery of the Kirishima volcanic area.

Sources:

- Tsutsui et al (2006) "Eruptive History of Ohachi Volcano, Kirishima Volcano Group, Southern Kyushu, Japan", Bull Volc Soc Japan (Kazan), 52: 1-21
- Ryusuke IMURA (1989) "Eruptive History of the Kirishima Volcano during the past 22,000 years" Master Thesis Kagoshima University, March 1989
- Tsuyoshi Miyamoto (2005) "Magma chamber structure of Katazoe scoria eruption, Ohachi volcano at Kirishima volcanoes", PhD thesis, CNEAS, Tohoku Univ.
- Fujita Shun'ichi (2000) "Geochemical aspect on the genesis of the hydrothermal system of the Kirishima volcano and its southwestern area" Journal of the Balneological Society of Japan, v50 (1), pp 1-11

- Volcano Discovery | NHK | News24. [Translated].

FIRE IN THE SKY: "Glowing Object" - Meteor Fireball Caught On Camera Over Saudi Arabia! [VIDEO]

File photo.

February 10, 2016 - SAUDI ARABIA - A glowing object believed to be a large meteor was captured on camera as it crossed Saudi skies at night, a local newspaper reported on Wednesday.

An eight-second YouTube film published by Sabq Arabic language daily showed the object lightened up the sky in the Northern Rafha town as it moved fast from East to North before disappearing.

The paper said many residents captured the object with their mobile phones and quoted well-known Saudi astronomer Khaled Al Zuaq as saying he believes it was a meteor.

"The object appeared to be a large meteor which was seen crossing the Saudi skies at around 10.30 pm," he said.


WATCH: Meteor over Saudi Arabia.

- Emirates 24/7.

GEOLOGICAL UPHEAVALS: Scientists Claim Mysterious Menominee Crack In Michigan Is Unusual "GEOLOGICAL POP-UP" Feature - But Don't Know What Caused It?!

A photo taken in 2010 of the Menominee Crack, a 'pop-up' geological feature. Credit: Wayne Pennington/ Michigan Technological University 

February 10, 2016 - MICHIGAN, UNITED STATES - Seismologists studying a massive crack in the ground that appeared north of Menominee, Michigan in 2010 now think they know what the unusual feature might be. But as they explain in their study published this week in the journal Seismological Research Letters, there are still some mysteries to clear up about the strange geological occurrence in the rural Michigan woods.

A team of scientists led by Wayne Pennington of Michigan Technological University says that the crack, which lies along the crest of a two-meter-high ridge that appeared at the same time, is probably a "pop-up" feature. Pop-ups occur in places where shallowly-buried rock layers spring upward after having been weighed down by rock or ice. Pop-ups—sometimes called "A-tents" for their shape—may develop in places where the earth rebounds upward after an overlying glacier shrinks away, or when rock overburden is removed in a quarry.

However, the last glaciers retreated from Menominee 11,000 years ago—and there isn't any quarrying in the area.

"One of our reasons for publishing this was that in our search of the literature we could find no other mention of modern pop-ups that didn't occur at something like the base of a quarry, where people had removed massive amounts of rock earlier," Pennington explained. "As far as we can tell, this is a one-of-a-kind event."

Residents near Menominee heard a loud noise and shaking in the early morning of October 4, 2010, and soon discovered the crack when they went into the nearby woods to clean up the debris left from removing a big double-trunked white pine tree a few days earlier. The crack split the ground for 110 meters, and was as deep as 1.7 meters in some places. Tree trunks tilted at precarious angles on either side of the fracture. Pennington went to visit the site on his way back home from a scientific conference, he recalled. He paced off some measurements in his dress shoes and collected some GPS data with his phone. "I was completely blown away by it, because it wasn't what I was expecting when I saw it," he recalled. "It wasn't like anything I had seen before."

Trees tilt away from either side of the Menominee Crack 'pop-up' feature. Credit: Wayne Pennington/ Michigan Technological University 

Although the crack was the most dramatic feature, Pennington was intrigued by the new ridge underneath it. "I kept trying to think of ways that there could have been an uplift from a thrusting earthquake or something, but anything like that requires such a huge amount of displacement in order to produce that amount of crustal shortening, that nothing made sense."

He shared the photos and data with his colleagues, until Stanford University geophysicist Norm Sleep pointed out that the feature formed from a shallow-buried layer of limestone, and looked like a pop-up. "This made perfect sense to us," Pennington said, "except for what caused it. And that then became the puzzle."

The researchers needed to get a better look at the rock underneath the ridge to confirm that it was a pop-up, so they turned to a technique called seismic refraction. The technique measures the speed of seismic waves as they travel within layers of the earth, as determined at different distances from the seismic source. In this case, the seismologists used a sledgehammer to strike a large metal ball lying on the ground, and captured the resulting seismic waves.

In broken rock, the waves travel faster as they move parallel to cracks in the rock, and slower when they move perpendicular to the cracks and have to travel across the fractures. The scientists found a pattern of refraction speeds that seemed to be consistent with the intense bending and then fracturing of the brittle limestone of a pop-up feature.

But what caused the pop-up to...pop-up? Without the usual suspects in play, Pennington and his colleagues had to do a little detective work. The limestone in the area may have been stressed almost to the point of cracking when the last glaciers retreated, they say. The recent removal of the double-trunked pine, which may have weighed as much as 2000 kilograms—over two tons—could have been the final straw, allowing the rock to bend upward when that weight was removed. "There's a 60% chance that this explanation we provide is the right one," Pennington noted. "But since we haven't seen this kind of thing elsewhere, and the tree is such a small effect, we wonder if there might be something else."

The seismologists studied aerial photos of the region to see how soil has been removed in the past 50 years from road work and a re-design of the area's drainage system. These changes might have channeled more rainwater below the surface, potentially weakening the rock as it froze and thawed, the scientists suggest.

Pennington said "no one should be losing sleep" over the strange feature, which technically counted as the first natural earthquake in Michigan's Upper Peninsula—measuring less than magnitude 1.

"It may be a one-of-a kind phenomenon," he said. "But if it happens again, we'll be all over it, trying to figure it out." - Phys.org.

PLANETARY TREMORS: Strong 6.3 Magnitude Earthquake Rocks Chilean Coast - Tremors Felt In Western Argentina! [MAPS + TECTONIC SUMMARY]

USGS earthquake location.

February 9, 2016 - CHILE -  A strong earthquake with a preliminary magnitude of 6.3 has struck off the coast of central Chile, centered off Tongoy and La Serena, seismologists say. No tsunami warnings have been issued.

The earthquake, which struck at 9:33 p.m. local time on Tuesday, was centered in the ocean about 48 kilometers southwest of the coastal town of Tongoy, or 89 kilometers southwest of La Serena. It struck about 19 kilometers deep, making it a shallow earthquake, according to Chile's national seismological agency.

USGS shakemap intensity.

Moderate shaking was felt in the Coquimbo Region, according to Chile's National Office of Emergency of the Interior Ministry (ONEMI). "The characteristics of the earthquake do not meet the conditions necessary to generate a tsunami off the coast of Chile," ONEMI said in an alert. No tsunami warnings have been issued.

Citizens on the streets of La Serena. In some localities power outages were reported , but no major damage has been reported so far

Other details were not yet available, but there were no immediate reports of damage or casualties.

Chile and the wider region are on the so-called 'Pacific Ring of Fire' which is regularly struck by large earthquakes, including the Great Chilean earthquake that struck the coast of central Chile on May 22, 1960. The 9.5-magnitude earthquake, the largest earthquake ever instrumentally recorded, left between 490 and 5,700 people killed.  - BNO News.

Seismotectonics of South America (Nazca Plate Region)

The South American arc extends over 7,000 km, from the Chilean margin triple junction offshore of southern Chile to its intersection with the Panama fracture zone, offshore of the southern coast of Panama in Central America. It marks the plate boundary between the subducting Nazca plate and the South America plate, where the oceanic crust and lithosphere of the Nazca plate begin their descent into the mantle beneath South America. The convergence associated with this subduction process is responsible for the uplift of the Andes Mountains, and for the active volcanic chain present along much of this deformation front. Relative to a fixed South America plate, the Nazca plate moves slightly north of eastwards at a rate varying from approximately 80 mm/yr in the south to approximately 65 mm/yr in the north. Although the rate of subduction varies little along the entire arc, there are complex changes in the geologic processes along the subduction zone that dramatically influence volcanic activity, crustal deformation, earthquake generation and occurrence all along the western edge of South America.

Most of the large earthquakes in South America are constrained to shallow depths of 0 to 70 km resulting from both crustal and interplate deformation. Crustal earthquakes result from deformation and mountain building in the overriding South America plate and generate earthquakes as deep as approximately 50 km. Interplate earthquakes occur due to slip along the dipping interface between the Nazca and the South American plates. Interplate earthquakes in this region are frequent and often large, and occur between the depths of approximately 10 and 60 km. Since 1900, numerous magnitude 8 or larger earthquakes have occurred on this subduction zone interface that were followed by devastating tsunamis, including the 1960 M9.5 earthquake in southern Chile, the largest instrumentally recorded earthquake in the world. Other notable shallow tsunami-generating earthquakes include the 1906 M8.5 earthquake near Esmeraldas, Ecuador, the 1922 M8.5 earthquake near Coquimbo, Chile, the 2001 M8.4 Arequipa, Peru earthquake, the 2007 M8.0 earthquake near Pisco, Peru, and the 2010 M8.8 Maule, Chile earthquake located just north of the 1960 event.

USGS plate tectonics for the region.

Large intermediate-depth earthquakes (those occurring between depths of approximately 70 and 300 km) are relatively limited in size and spatial extent in South America, and occur within the Nazca plate as a result of internal deformation within the subducting plate. These earthquakes generally cluster beneath northern Chile and southwestern Bolivia, and to a lesser extent beneath northern Peru and southern Ecuador, with depths between 110 and 130 km. Most of these earthquakes occur adjacent to the bend in the coastline between Peru and Chile. The most recent large intermediate-depth earthquake in this region was the 2005 M7.8 Tarapaca, Chile earthquake.

Earthquakes can also be generated to depths greater than 600 km as a result of continued internal deformation of the subducting Nazca plate. Deep-focus earthquakes in South America are not observed from a depth range of approximately 300 to 500 km. Instead, deep earthquakes in this region occur at depths of 500 to 650 km and are concentrated into two zones: one that runs beneath the Peru-Brazil border and another that extends from central Bolivia to central Argentina. These earthquakes generally do not exhibit large magnitudes. An exception to this was the 1994 Bolivian earthquake in northwestern Bolivia. This M8.2 earthquake occurred at a depth of 631 km, making it the largest deep-focus earthquake instrumentally recorded, and was felt widely throughout South and North America.

Subduction of the Nazca plate is geometrically complex and impacts the geology and seismicity of the western edge of South America. The intermediate-depth regions of the subducting Nazca plate can be segmented into five sections based on their angle of subduction beneath the South America plate. Three segments are characterized by steeply dipping subduction; the other two by near-horizontal subduction. The Nazca plate beneath northern Ecuador, southern Peru to northern Chile, and southern Chile descend into the mantle at angles of 25° to 30°. In contrast, the slab beneath southern Ecuador to central Peru, and under central Chile, is subducting at a shallow angle of approximately 10° or less. In these regions of “flat-slab” subduction, the Nazca plate moves horizontally for several hundred kilometers before continuing its descent into the mantle, and is shadowed by an extended zone of crustal seismicity in the overlying South America plate. Although the South America plate exhibits a chain of active volcanism resulting from the subduction and partial melting of the Nazca oceanic lithosphere along most of the arc, these regions of inferred shallow subduction correlate with an absence of volcanic activity. - USGS.