View Full Version : Japan's Shinmoedake Volcano Erupts

13-03-11, 04:55 PM

The Shinmoedake volcano in Japan's Kyushu has erupted two days after the massive earthquake and tsunami that left more than 10,000 people dead, reports said on Sunday. There was no confirmation on whether the eruption was related to Friday's quake.

The volcano, which was dormant for several weeks after erupting on January 19, began spewing ash and rock on Sunday, Japan's meteorological agency said. The agency did not specify if the new eruption was related to the quake.

Earlier recorded eruptions of Shinmoedake were in 1716, 1717, 1771, 1822, 1959, 1991, 2008 and 2009. The eruption of Shinmoedake in January, which was the biggest volcanic activity in Shinmoedake in 52 years, had caused widespread destruction and panic.

Glass panes on buildings as far away as four miles were shattered in the blast and the bang could be heard further away. Hundreds of people had fled the area after volcanic debris, like hot ash and rocks, flew more than 2,000 meters up in the air, BBC had reported.

Volcanologists had warned then that a "dome of lava was growing larger inside the volcano's crater" though it was uncertain if it would blow the top off any time soon.


13-03-11, 05:30 PM
uh oh . . .

13-03-11, 05:36 PM
When it rains it pours.

13-03-11, 05:58 PM
Japan doesn't deserve any of this! Really feel for the peple there - and hope all our Japanese mebrs are OK!
I don't think the eruption will be anything directly to do with the earthquake, except that they are both part of the same plate tectonic collision - the Pacific Plate is going uder the Asian/Japanese, when it sticks and then jerks there's an earthquake, and as the sediment etc that's carried down with it melts, it bubbles up and feeds volcanoes. But if the Pacific Plate did jerk forward/down by several metres (did it? or did the Asian Plate jerk back from being pulled down with it?), the sediment would take at least years maybe thousands of years to melt and find its way up into the base of the volcano. And I think Kyushu is at the other end of Japan?
So part of the same geologicalprocess but no direct connection, I think.
I only hope the avoid a melt-down in those reactors! Good luck all Japanese cdg members, and everyone over there!

13-03-11, 06:14 PM
simply unreal and very sad
they certainly need a break.....

13-03-11, 06:29 PM
I am very worried about cdg members in Japan, as you know we have posting dudes from there I sent them pms but no one has replied. Very depressing, I can't imagine what it must be for them right now.

I hope they are OK.

And DD, just for the record there is no "Japan Plate".

Japan is a volcanic arc island, these are only formed in subduction zones.

Four plates interact near japan

Pacific Plate
Eurasian Plate
North American Plate
Fillipino Plate

For this reason Japan is the most earthquake prone country in the world.


Here is a summary of the Sendai Earthquake by the USGS

The 03/11/2011 earthquake near the east coast of Honshu, Japan, occurred as a result of thrust faulting on or near the subduction zone interface plate boundary between the Pacific and North America plates. At the latitude of this earthquake, the Pacific plate moves approximately westwards with respect to the North America plate at a velocity of 83 mm/yr. The Pacific plate thrusts underneath Japan at the Japan Trench, and dips to the west beneath Eurasia. The location, depth, and focal mechanism of the March 11 earthquake are consistent with the event having occurred as thrust faulting associated with subduction along this plate boundary. Note that some authors divide this region into several microplates that together define the relative motions between the larger Pacific, North America and Eurasia plates; these include the Okhotsk and Amur microplates that are respectively part of North America and Eurasia. The March 11 earthquake was preceded by a series of large foreshocks over the previous two days, beginning on March 9th with an M 7.2 event approximately 40 km from the March 11 earthquake, and continuing with a further 3 earthquakes greater than M 6 on the same day.
The Japan Trench subduction zone has hosted 9 events of magnitude 7 or greater since 1973. The largest of these was an M 7.8 earthquake approximately 260 km to the north of the March 11 event, in December 1994, which caused 3 fatalities and almost 700 injuries. In June of 1978, an M 7.7 earthquake 35 km to the southwest caused 22 fatalities and over 400 injuries.

13-03-11, 08:35 PM
You are right - Japan is an island arc, over the subdunction zone where ther Pacific plate goes under the Asian plate - so I think that makes Japan part of the Asian Plate. Not not the North american Plate - thats the other side of the Pacific!

13-03-11, 08:43 PM
No mate, read my post again. The megathrust earthquake occured on a section of a fault where the Pacific plate is subducting under the North American plate.

Asia plate is actually called Eurasian plate - it's one continent, Europe and Asia are one continent DD.

UK, Bulgaria, China etc are on the same tectonic plate.

Japan was originally attached to the eastern coast of the Eurasian continent. The subducting plates, being deeper than the Eurasian plate, pulled Japan eastward, opening the Sea of Japan around 15 million years ago.

13-03-11, 08:52 PM
Eurasian Plate, yes - Europe and asia are normally classed as the same continent/plate (the Urals were the weld linme (that's not the right technical word - suture!). But surely Japan can't be on the North American plate - if that's what the USGS website says, surely must be a slip for Eurasian Plate?

13-03-11, 08:59 PM
Just checked. Oops, looks like I'm wrog - there really is a bit of the North american Plate that exended into northeast siberial and the north end of Japan - just a narrow srip in northern Japan, between the Pacific and Eurasian Plates. http://en.wikipedia.org/wiki/File:Plates_tect2_en.svg
Ok, you win Meatpie, I didn't know that!

13-03-11, 09:02 PM
dead it IS the North American Plate: (We do everything larger . . . hehe)

13-03-11, 09:40 PM

13-03-11, 09:46 PM
Its been wanting to blow for a while.


13-03-11, 09:48 PM
and posted on Januay 26, 2011


13-03-11, 09:55 PM
OMG Beuen! (I was waiting for our real man to show up!)

13-03-11, 10:00 PM
Just checked. Oops, looks like I'm wrog - there really is a bit of the North american Plate that exended into northeast siberial and the north end of Japan - just a narrow srip in northern Japan, between the Pacific and Eurasian Plates. http://en.wikipedia.org/wiki/File:Plates_tect2_en.svg
Ok, you win Meatpie, I didn't know that!

Cheers m8, no one knows everything.

As I said Japan is a volcanic arc, large part of it was formed by tectonic accretion - part of sea floor mostly sediment instead of sinking with the subducting plate get bulldozed and added to the island.


When I graduted from high school several dudes went to study geology at the Universtiy of Sofia. We often met and they gave me long lectures on plate tectonics, I loved it. That was years ago.

The saddest part is that they all ended up unemployed in 2010 and even though they have the knowledge they can't get any jobs related to their field of study.

I talked with that same dude last year, we travelled together on a train.

He was absolutely depressed as many others of my former classmates.