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400 explosions and counting!

November 7, 2009

Many thanks to Wes for passing on information that “explosive eruptions” at Sakurajima passed the 400 mark earlier this week: should Kagoshima start preparing for the big one?!

As the article states, this year has seen the greatest number of explosions for 24 years and activity is very similar to that which preceded the large Showa eruption in 1946. That time lava spewed out from the Showa crater covering much of the eastern flank of the volcano. If this were to happen again, well dear visitors of Kagoshima, you’re in for a treat! Despite damage to local agriculture – and there is a farmer who currently grows broad beans in that vicinity – the prospect of viewing live lava flows would provide a huge boost to local tourism.

However, if explosivity was to increase…

Sakurajima from space (NASA Earth Observatory, via the Eruptions blog)

A recent image of Sakurajima from space (NASA Earth Observatory, via the Eruptions blog). Spot the ash plume in the centre, although much of the haze is from the Asian continent.

Elsewhere, JMA have also published a nice report on their website (in Japanese). The ever-changing colour of the lake at Naka-Dake (中岳), Mount Aso (阿蘇山) has always lured volcanologists, but recent pictures also show a red glow to the side of the crater:

Naka-dake (中岳) crater and area of red glow (from JMA)

Naka-dake crater, Aso and area of red glow (from JMA)

Red glow at Naka-Dake (JMA)

Red glow at side of Naka-Dake crater (from JMA)

What this means I do not know, but there are around nine craters up at Naka-dake and the magma source has shifted activity from one to the next over the years. One outrageous suggestion could be that this is the start of a new shift? We shall have to see – for now the activity remains ‘normal’ and no doubt the glow will provide an extra attraction for the bus tour groups that continue to ride the horrible tarmac all the way to the top.

Ikimashou…

October 25, 2009
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The Mountain Man

October 18, 2009

"Volcano Asama" by Umetaro Azechi (image: Fine Arts Museums of San Francisco)

"Mount Asama" (1953) by Umetaro Azechi (image: Fine Arts Museums of San Francisco)

I am probably committing a huge infringement of copyright laws, but it’s nice to come across artwork of Japanese volcanoes that is not in the guise of traditional woodblock images of Mt. Fuji – as wonderful as they are.

I came across Umetaro Azechi (1902-1999) while exploring the British Museum a few months ago, where framed in the corner of the ‘Japan Room’ was a woodcut of his, titled Mountain Man. Simple, yet jumping out at you, the mountain man was defiant – perhaps a Japanese male refusing to go to the office; instead heading to where the real action is. I couldn’t find the same image online, but here is an equally simple print of Mt. Asama, almost South American in appearance. It could be the Columbian Andes rather than a volcano on the Kanto plain!

You can read more about Azechi – a keen mountain lover – here, a site which also includes a great representation of the winter mountaineer.

Satsuma-Fuji

October 11, 2009
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Sunrise at Kaimon-dake (開聞岳): possibly the finest sunrise I have ever witnessed.

As you may be able to tell, Kaimon is commonly referred to as the “Mount Fuji of Satsuma” (where Satsuma was the old province that now forms a large part of the present day prefecture of Kagoshima). The hike up is a reasonable circular path starting around sea-level and finishing at the 924m summit with clear-weather views towards the smoking peaks of Sakurajima to the north and Satsuma-Iojima to the south. However, for many volcano lovers the mountain’s shape is enough to wetten the appetite and it certainly has my vote as the best Fuji-San imitation.

What’s yours?

Mt. Asama and cosmic rays

October 6, 2009
Active vent of Mt. Asama (photo: Tokyo University)

The active vent of Mt. Asama (photo: Tokyo University)

I love the ingenuity of Japanese volcanologists.

After drilling into Mt. Unzen and sending unmanned machines in to build sabo dams, the New Scientist reports this week that scientists from Tokyo University have demonstrated a technique to measure the mass of material inside a volcano using cosmic radiation. They have “looked” into Mt Asama!

By measuring very complicated-sounding particles called muons, which are formed when cosmic rays interact with our atmosphere, the Tokyo scientists have been able to measure how they pass through the solid Earth. Passing through rocks of different densities the muons are absorbed at different rates, thus under a volcano one can locate molten magma. Understand?!

Essentially, they have been able to “scan” the volcano and come up with a picture of what its inner structure might look like – analogous to an MRI scan to view an unborn baby, say. At Asama volcano, they were able to do this before and after an eruption (in February earlier this year) and calculate just how much material was erupted. The answer? Over 30,000 tonnes – puny in terms of big eruptions, but an accurate figure compared to estimates of total ash fall.

This now means that volcanologists may be able to look at the insides of a volcano like never before: an obvious benefit for monitoring activity. One day they might even be able to see “shifting magma” – a curious insight into the world below.

When it rains, it pours

October 5, 2009

More ash in Kagoshima...

More ash in Kagoshima...

Active Japan

October 1, 2009

Unfortunately Japanese volcanoes only get a brief mention in the SI/USGS Weekly Activity Reports, but here is the current status of the most active volcanoes in the country as of September 27th. Below are the English translations of the volcano names and you will see that Sakurajima is the only volcano with an elevated alert status of level 3: an explosive summer appears to be continuing into autumn – so far today (1st Oct.) there have been 14 explosions!

Volcanic Alert Levels (from JMA; click for more in Japanese)

Volcanic Alert Levels (from JMA; click for more in Japanese)

浅間山, Asama: level 2.

三宅島, Miyakejima: level 2.

桜島, Sakurajima: level 3.

薩摩硫黄島, Satsuma-Iojima: level 2.

口永良部島, Kuchinoerabujima: level 2.

諏訪瀬島, Suwanosejima: level 2.


Ash from Sakurajima on a van (photo: flickr user africadunc)

Ash from Sakurajima on a van (photo: flickr user africadunc)

Crazy Victorians

September 23, 2009

In the absence of regular volcano profile posts I thought it would be a good idea to provide a few images that show the beauty or uniqueness of Japanese volcanoes, or have a good story behind them – well, this photograph certainly has!

The image above comes from Okinawa Soba’s excellent flickr photostream and shows was taken by the the British photographer Herbert G. Ponting (left) capturing during an eruption at Mt. Asama (浅間山) volcano in 1903. Upon ascending the mountain, the climbing party suddenly found themselves engulfed in an explosion, in which Ponting himself thought his “last moment had surely come” as they managed to avoid the falling stones and escape the sulphurous fumes that enveloped them. Ponting relives the episode in his book ‘In Lotus Land’, providing a quite beautiful description of the explosive forces in action:

Great black whorls of smoke belched from the crater, being emitted with such force and volume that they were pushed far back into the teeth of the wind; and several times we had to retreat quickly as they bellied towards us. They rose to the heavens in writhing convolutions, and from the centre of the mass billows of snow-white steam puffed out, and bulged beyond the smoke.

However the real story here is not the explosion, but the reaction of our Victorian friend:

Here was a wonderful chance to secure a unique photograph, but on looking around for the coolies I saw them rushing madly down the mountainside with my cameras as fast as legs could carry them. Realising that if I did not stop them I would miss the chance of a lifetime to get a picture at the lip of a volcano in a state of violent activity, I ran after them calling for them to stop.

… Failing to check them with my shouts, I went after them, and, being unencumbered, soon overhauled the man with my hand camera; but he was half-crazed with fear, and not all my entreaties could make him slack his pace. Seeing the chance of a unique picture slip away – for I knew the best smoke effects would quickly be over – I was reluctantly compelled to use a more forcible method, which had the desired effect.

I haven’t actually visited Mt. Asama yet, but until I do I am left with the enduring image of a moustached man in a suit, in the words of Okinawa Soba, beating the crap out of some poor Japanese guy on the side of an erupting volcano. I suppose you could do worse…

Forgotten islands on the southern seas…

September 20, 2009

My bike on the island of Nakanoshima

Cycling on the island of Nakanoshima

Every year a special ferry service departs Kagoshima to dispense medical check-ups and treatment at each of the Tokara Islands. For the curious tourist who times their trip right, a one-way ticket can therefore become something of a cruise allowing you to jump on and jump off as the journey progresses southwards. I have been such a tourist, lucky that an excursion with my sensei to conduct fieldwork in Suwanosejima would take us not only to our destination, but to a number of ‘bonus’ volcanoes en route. Bicycle in tow, we had approximately an hour to sprint around at each stop and although any volcanological research was certainly limited in this time, it provided me with an extra insight into island life that seems so distant from the accepted “Japan experience”. The people here have lived on the edge of the Japanese psyche for centuries and if it were not for a few important events – such as the nearby Tanegashima, acknowledged for the first contact with Europeans and the introduction of firearms in the 16th century when a Portuguese was seen to shoot at a duck – these islands would probably remain largely forgotten. Indeed, in the ferry port waiting room at Suwanosejima (which is basically a wooden shed) is pinned a photograph of the local school: a grand total of 7 students, aged 8-15 years old. One cannot help but worry for the future of this island way of life.

Societal worries aside, these islands provide a wonderful selection of volcanoes to explore. Apart from their natural beauty, one of the major draws for me is the fact that they are simply unknown outside of Japan. Kuchinoerabujima, recently infamous for the disappearence of an American poet, and Suwanosejima, Japan’s “most explosive volcano”, are probably the only well studied volcanoes and thus are reasonably familiar to the international ‘volcanological community’. However, through this post I hope to introduce a few more names that might be of interest to the budding geologist, the seasoned Japanophile or the inquisitive browser.

Read more…

Welcome

August 23, 2009

Welcome to the new blog ‘The Volcanoes of Japan’!

Sakurajima explosion, April 2009 (photo: Daiki)

Sakurajima explosion, April 2009 (photo: Daiki)

Japan is home to around 10% of the world’s volcanoes, but surprisingly only a few feature in the mind of the average foreign visitor or volcano enthusiast. Of those that do, information in the English language is somewhat limited to detailed scientific studies or brief touristic descriptions. Admittedly Mount Fuji is much the symbol of Japan let alone the iconic ’stratovolcano’ form, but beyond this some wonderful mountains remain hidden and unknown to the country’s travelers.

This small and humble guide acts as an introduction to the amazing volcanoes I, a self-confessed kazan otaku (volcano geek), have visited during my time as a research student in Kagoshima and, hopefully, also to those that I intend to visit in the future. It is a longterm project – a hobby on my part – so my apologies in advance for the long wait between entries! In the likely event that this blog fails to provide the enlightenment you are looking for, please find a number of useful links in the sidebar.

Every volcano in Japan is unique in its own special way. I hope to convince you of this fact and maybe one day you might even attempt to make a volcanic pilgrimage to Japan for yourself…

Sakurajima explosion, April 2009 (photo: Daiki)

Sakurajima explosion, April 2009 (photo: Daiki)