Thursday, September 6, 2012

Scientists Warn Further About Mt Fuji, Japan

While it was never confirmed if Mt Fuji ever had a minor eruption which resulted in the creation of a new flank crater, it is now confirmed that the recent quake activity in the area (A 9.0, 6.4, and 5.0) around Mt. Fuji has indeed increased drastically the amount of pressure in the magma chamber of the iconic Japanese volcano. The current pressure in the chamber has reached a high level of 1.6 megapascals, which Japanese scientists are quoted as saying "is not a small figure". It has been noted that many eruptions occur with a mere 0.1 megapascals of pressure in the chamber.

Steam activity, small water eruptions, and large holes that are emitting volcanic gasses are starting to occur in the vicinity, and the crater is fuming (However I have only been able to cite this from the linked Wired.com article, and have seen no real evidence of this with cameras, video, or other sources, so don't take my word for that).

This is the most activity in the area since a swarm of low-frequency quakes occurred in 2000-2001, and began after the large 9.0, and 6.4 quakes. With the current activity, it is quite evident that the earthquake has re-pressurized the magma chamber. It is quite likely that this will remain the case until more seismicity, which is highly likely in the area, occurs and puts more pressure into the system.

One scientist has gone so far to say that he expects an eruption from Fuji now within "the next three years". Another major cause for concern about the volcano is that a new 34km long fault line was discovered after the major 9.0 2011 quake, which runs directly underneath the volcano, and if destabilized, could result in partial or total collapse of Mt. Fuji.

It is my opinion that the current activity will probably not lead to an imminent eruption (scientists have to be careful with what info they put out, you don't want to cause panic, but you also don't want to be unprepared, and erring on the side of caution is what saves lives), but you will probably see a lot of hydrothermal activity, including but not limited to, minor phreatic eruptions, increased fumerole action, and possibly some deflation/inflation (DI) events. The activity at the volcano is quite similar to the type of activity now being seen at Mt. Iliamna volcano in Alaska, which also experienced a minor magma intrusion, but has merely increased its gas emissions and level of small seismicity. Iliamna has not erupted yet, but has been on AVO's 'watch' list for nearly a year now.

An eruption from Mt. Fuji today has been estimated at a damage cost of up to ¥2.5 trillion ($3.25 billion) to the Japanese economy, and could also cost over 300,000 lives. It is critical that those living near this volcano understand the dangers, and have an evacuation plan as well as supplies they can rely on in the event this does occur. The volcano, at its full fury, is capable of massive levels of destruction to the immediate area, and includes in its arsenal the potential for pyroclastic flows, landslides, lahars, phreatic eruptions, fissures, pyroclastic cinder cones, and fast flowing pahoehoe basalt lavas.

The last eruption in 1707 blasted out a large crater on the Eastern slope of Fuji, and deposited ash as far away as Tokyo. Many buildings and towns surrounding the volcano are built on the lavas and ashes of this eruption. Due to the extensive history and record keeping of Japan, most residents are quite aware of the dangers of Fuji, and typically take any evacuation order very seriously, but pyroclastic flows are a hard thing to outrun when they can reach speeds of up to 280mph, so early warning is the best possible scenario.

I will also to see if there are any other credible sources to confirm what Wired.com is claiming in regards to steaming and gas emissions (however they did not cite a source for this claim). Its actually possible that they could be using my blog as the source for this, as I was among the first sites to report the initial supposed 'emissions' from Fuji, which I was never able to confirm save one obscure report in Japanese news.

Scientists will more than likely step up their monitoring and analysis of Fuji in the mean time, and keep a close watch on its goings-on.


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