Ontake, Japan, erupts

Ontake erupts. Photo by andreijejune as cited above.
The eruption started around 11:53 a.m. Saturday, local
time (in spite of the setting in the caption above)

UPDATE SUNDAY: The Japan Times is reporting that 31 people were found unconscious near the peak of Ontake, and that four have been pronounced dead. The BBC is reporting that there were a total of 45 missing climbers. Japanese officials only announce deaths after a formal examination by a doctor. I extend condolences to the families of the victims and missing.

A few hours ago (Saturday), Mount Ontake 155 miles west of Tokyo, erupted, sending a steamy ash plume high into the sky. It last erupted in 2007. News is conflicting about the casualties, but at least one person has been killed,  thirty people have been injured and the Japanese are organizing to rescue an unknown number (reports vary between 41 and 200?) people who were climbing on the mountain. As much as 20" of ash has been reported on the ground near the summit, and Japanese authorities are issuing an alert to stay at least 4 miles away from the summit. The alert level is "3" meaning "do not approach the volcano." Ash is reported to have gone 3 kilometers down the mountain in a pyroclastic flow. There are a number of YouTube videos showing the eruption through cameras held by hikers. Here's one.

From the Kinja Space site cited
in the text and the twitter
user identified above.

Ontake is the second highest volcano in Japan, at 3,067 meters, second to Mount Fuji. There is a nice description of the tectonic setting of Ontake, as well as a collection of eyewitness accounts, at Kinja Space, authored by Mika McKinnon, from which I take much of the following discussion. The author of this blog nicely states that because of geochemical differences in the magmas, volcanoes over oceanic tectonic plates typically have a relatively low abundance of silica (SiO2) and are fairly fluid allowing their gases to escape rather gently (think Iceland, Hawaii). When the eruptions do turn explosive, it is usually because the magma has interacted with groundwater or ice.  Volcanoes that are rich in silica are viscous and gases don't escape easily, leading to conditions that produce explosive eruptions. Such volcanoes usually are found where oceanic and continental plates intersect. The Pacific Ring of fire that stretches up from South America, through western North America and around to Japan is such a setting and eruptions here can be very dangerous. Eruptions of these volcanoes produce flying rocks, volcanic bombs, and hot pyroclastic flows. The movies of the survivors are lucky to be alive.

Ontake had a minor eruption involving water (phreatic) in 2007, but the last major eruption stretched from October 1979-April 1980. In spite of claims that it had erupted in 1892 and 774 AD, detailed examination of the records suggest that this is not true and that it had not erupted prior to the 1979-1980 sequence in recorded history, which is a long time in Japan. Local volcanologists/seismologists Koshun Yamaoka and Shigeo Aramaki are suggesting that the billowing white clouds seen in the eyewitness photos suggest that this is a phreatic eruption.  The possibility that phreatic eruptions are signaling heating of groundwater by rising magma leaves open the scenario of a major magmatic eruption like that of Mount St. Helens that began about 4 hours after the 1980 March-April lateral blast.

Mayon and Bardarbunga volcanoes.

Mayon volcano, copyright Tom Tam shot from
Lingnon hill in Daraga Town near the volcano and his home

Mayon, a stratovolcano of nearly perfect symmetry, in the Philippines is again active. It is one of the most active volcanoes in the world. It has erupted 49 times in the past 400 years.  Coincidentally, the most destructive eruption was in 1814, a year before Mount Tambora erupted, with the emission of ash that led to the "Year without a summer" in 1816.  New reports today are that more than10,000 people from around the volcano are being evacuated.

The volcanic activity is being actively reported on Wiki here, and here is the link to the Philippine Institute of Volcanology and Seismology, PHILVOLCS. The monitoring network has detected 39 rockfall events that are "ascribed to incipient breaching of the growing summit lava dome." Continuing seismicity indicates either magma intrusion or volcanic gas activity, and there is sufficient magma in the summit crater to cause a red glow. PHILVOCS has raised the alert level to Level 3, stating that a hazardous eruption is "possible within weeks." A Permanent Danger Zone extends out to a 6 km radius, and an Extended Danger Zone to 7 km. These are being evacuated because of danger of rockfalls, landslides, and lava/ash/mud flows. (Level 3 is the third highest level of alert, following "eruption" and "imminent eruption.")

Bardarbunga in Iceland continues to be active seismically and as of a flyover of the Holuhraun fissure on Sept. 12, about 200 cu meters of magma per second are erupting. Lava is flowing nearly 20 km from the vent.

Major solar storm, alert for a CME, coronal mass ejection

Sunspot region 2158, the source of a solar flare today
From Spaceweather.com here

UPDATE 2: From space watch.com:

STORM WARNING (UPDATED): Among space weather forecasters, confidence is building that Earth's magnetic field will receive a double-blow from a pair of CMEs on Sept. 12th. The two storm clouds were propelled in our direction by explosions in the magnetic canopy of sunspot AR2158 on Sept. 9th and 10th, respectively. Strong geomagnetic storms are possible on Sept. 12th and 13th as a result of the consecutive impacts. Sky watchers, even those at mid-latitudes, should be alert for auroras in the nights ahead.

UPDATE 1: I have posted a number of relevant items over the past few years on solar storm activity: 

• General background about space weather, CME's and solar flare
• One of my most popular posts, a 2010 one titled "Solar activity (and Newt Gingrich)"
• An X5-class solar flare in March, 2012
• In January 2012, the biggest flare since 2005 and here.
• An aurora viewed as far south as the midwest
• And, another flare/CME on February 15, 2011___________________

While our daily earth-weather is filled with heat waves still hitting us as summer fades into autumn, something 'out there' is ready to hammer us! Sunspot region 2158 spat forth a "long duration X1.66 (R3-strong radio blackout) solar flare today. It peaked at 17:45 UTC on Sept. 11  (11:45 a.m. PST on Sept. 10).

This sunspot region has been active for a few months. On September 1 it was the source of a flare, but on the backside of the sun. However, this region is now directly facing the earth. Solar scientists are awaiting data, but they think that it's likely that a Coronal Mass Ejection (CME) of particles will follow.  Information is updated regularly at NOAA's Space Weather Prediction Center here.

Why should we care? A CME has the potential to disrupt electronics that we depend on, whether in space for communications or on earth in health care facilities, computer centers, or communications facilities. A CME can also pose biological risk to astronauts and to passengers and crew in high-altitudes--especially if they are flying cross-polar routes where the particles preferentially come into the earth along magnetic field lines.

According to Mike Wall, a senior writer at Space.com,  the sun "unleashed an X-class solar flare--the most powerful type" today, and it also fired off another intense flare yesterday. Fortunately, NASA in these times of diminishing funding, still has the Solar Dynamics Observatory spacecraft which recorded the event. The flare was an X1.6 storm, and space.com says that it "poses no danger to anyone on Earth or the astronauts living aboard the International Space Station." However, radio communications on earth, the side facing the sun could experience radio communications lasting 'more than an hour.' However, if the eruption is accompanied by a CME, in 2-3 days, there might be significant geomagnetic storms that can disrupt GPS signals, power grids, and  communications.

We are near the peak phase of the Sun's 11-year cycle (Solar Cycle 24), but this phase is the weakest in about 100 years....and that's a whole other discussion!

Meteorite impact in Nicargua: brief report

The crater from the meteorite impact
From this reference

A fragment of the meteorite passing close to earth has made a crater in Nicaragua. I'll post more when I've got some reliable information.

http://www.cnn.com/2014/09/08/tech/innovation/nicaragua-meteorite/index.html?hpt=hp_t2

A fissure near Bardarbunga volcano, Iceland, has erupted

Location of the fissure eruption at Bardarbunga
from www.bbc.com here

On Sunday, a "curtain of fire" developed along a fissure near Bardarbunga, causing a brief alert and a banning of planes flying within 6,000 feet of the volcano. The eruption was described as "calm but continuous."

A detailed chronology of the current activity is being maintained on Wiki. Seismic activity has been continuous, with lava erupting on August 29th in the Holuhraun lava field. The active fissure was about 600 m long, and the entire eruption appears to have been only about 4 hours long. Seismicity quoted down during the eruption, but then returned. On August 30th it appeared that the dyke stopped migrating north, but seismicity continued. Another eruption began at 4:00 a.m. on August 31st, producing a lava flow about 1 km wide, 3 km long, and several meters thick. The flow rate was estimated at 1000 cubic meters/second. Seismic activity is continuing. Updates are posted continuously on the Icelandic Met Office webpage. They've posted the adjacent interesting map showing road closures north of Vatnajokull as a result of the current activity and potential flooding (the hashed area north of the big ice cap).