Global CMT Raises Magnitude of Japan quake to 9.1!

It wouldn't be the first time scientists disagreed on exact magnitude, and now this:

Global CMT

Note: Thread title changed to reflect changing information. Initial report from link below. However, upon writing to the PTWC, I received the following response:

No, PTWC didn't raise the magnitude. The Global CMT project did. They are generally regarded as the best source for earthquake magnitudes among seismologists.

The USGS has not yet adopted the higher 9.1 magnitude.

From Quick CMT catalog
201103110546A NEAR EAST COAST OF HONSH

Date: 2011/ 3/11 Centroid Time: 5:47:32.8 GMT
Lat= 37.52 Lon= 143.05
Depth= 20.0 Half duration=70.0
Centroid time minus hypocenter time: 69.8
Moment Tensor: Expo=29 1.730 -0.281 -1.450 2.120 4.550 -0.657
Mw = 9.1 mb = 7.9 Ms = 7.9 Scalar Moment = 5.31e+29
Fault plane: strike=203 dip=10 slip=88
Fault plane: strike=25 dip=80 slip=90

The Japan earthquake was the fourth most powerful ever recorded with a magnitude of 9.1, twice more powerful than the initial estimate of 8.9, Gerard Fryer, geophysicist of the Pacific Tsunami Warning Center, said this morning.

Three others that were more powerful since the late 1800s when seismometers started measuring ground motions were in 9.5 in Chile in 1960, 9.2 in Alaska in 1964 and 9.1 in Sumatra in 2004, according to Fryer.

The new magnitude was adjusted based on the impact of the quake throughout the Pacific, he said. "It fits all measurements, including in Hawaii," Fryer said.

The U.S. Geological Survey estimate of the quake's magnitude is still 8.9.

It is not uncommon for scientists to estimate different magnitudes immediately after an earthquake.

www.staradvertiser.com...

This was an incredible quake, pegging the nearest seismic stations into total saturation, and here is my capture of it GEE:



This originally came up on the USGS site as two 7.9's, until one was then deleted, and then soon after they raised it to 8.8. Not long after that, they raised it to 8.9.

Earthquakes in the 9 range are very rare, and it may be the last one any of us ever see in our lifetimes. On the other hand, with the way things are going on the Japan subduction zone, with constant quakes still continuing, what happens next is anyone's guess.

This zone has repeatedly shown us it can die down and then all of a sudden increase in magnitude.

A check at the PTWC reveals they have not updated the event page yet:
ptwc.weather.gov...

But it could be somewhere else. Anyone find it, please post.

Uh I don't think 9.1 is twice 8.9, but definitely a powerful quake none the less.

Originally posted by PinkAndBlack
Uh I don't think 9.1 is twice 8.9, but definitely a powerful quake none the less.

Yes, it is. Each level of magnitude is 10 times more powerful. So for every .2 increase, it is twice as powerful.

reply to post by TrueAmerican


Not necessarily. The magnitude grows exponentially. It is not always 10 times more powerful if it goes up one degree.I dont believe a 5.0 is ten times more powerful than a 4.0. I could be mistaken though.

reply to post by faint1993


You are wrong, TA has his facts in order.

Every .2 increase in magnitude is a doubling of kinetic energy released.

Well, technically, it's a logarithmic scale...that's why a 9.0 is 10 times as powerful as an 8.0, and it means that a 9.1 is 1.6 times as powerful as an 8.9. Not quite 2, but close enough.

Now, whether or not it's 2, or 1.6, or 1000 times stronger than an 8.9, I don't think it matters...we can see how much energy was released. The attempts to quantify it are interesting, but the damage is done.

Well I suppose another reason this may be significant is that if it was a 9.1, it raises the likely maximum aftershock magnitude potential to 7.6. (Main shock mag minus 1.5)

We've already seen a 7.1 aftershock, so another bigger one statistically might be possible. But this zone has already deviated from the norm, so I am not predisposing anything. For all we know, we could still get the biggest quake ever recorded yet to come.

And I might point out that if they do get another huge quake, how that could affect a pending nuclear disaster. What was possible containment could turn into total disaster.

Just to post some sources:

Because of the logarithmic basis of the scale, each whole number increase in magnitude represents a tenfold increase in measured amplitude; in terms of energy, each whole number increase corresponds to an increase of about 31.6 times the amount of energy released, and each increase of 0.2 corresponds to a doubling of the energy released.

Wiki

It's still quite shaking with very frequent tremors, some above the 6.0

I noticed that quakes in the Gulf of California are showing up, too

5.6 2011/03/12 22:31:27 39.225 142.333 25.8 NEAR THE EAST COAST OF HONSHU, JAPAN 6.3 2011/03/12 22:12:46 37.662 141.959 14.3 NEAR THE EAST COAST OF HONSHU, JAPAN
5.3 2011/03/12 21:58:17 39.055 142.319 25.9 NEAR THE EAST COAST OF HONSHU, JAPAN
5.5 2011/03/12 21:48:09 39.626 142.565 24.9 NEAR THE EAST COAST OF HONSHU, JAPAN
5.0 2011/03/12 21:40:58 37.170 143.354 25.3 OFF THE EAST COAST OF HONSHU, JAPAN
5.0 2011/03/12 21:38:35 37.934 144.251 26.2 OFF THE EAST COAST OF HONSHU, JAPAN
5.2 2011/03/12 20:09:55 36.747 144.050 24.2 OFF THE EAST COAST OF HONSHU, JAPAN
5.0 2011/03/12 20:08:25 35.775 141.893 24.5 NEAR THE EAST COAST OF HONSHU, JAPAN
5.0 2011/03/12 19:45:19 -6.187 154.385 62.0 BOUGAINVILLE REGION, PAPUA NEW GUINEA
5.1 2011/03/12 19:11:59 37.730 142.587 13.7 OFF THE EAST COAST OF HONSHU, JAPAN
5.0 2011/03/12 18:28:39 -56.851 -27.963 235.8 SOUTH SANDWICH ISLANDS REGION
6.0 2011/03/12 17:19:24 36.573 142.645 4.3 OFF THE EAST COAST OF HONSHU, JAPAN
5.1 2011/03/12 17:13:02 25.466 -109.727 10.0 GULF OF CALIFORNIA
5.2 2011/03/12 17:11:09 38.051 144.071 29.1 OFF THE EAST COAST OF HONSHU, JAPAN
5.1 2011/03/12 17:01:22 37.701 143.353 38.5 OFF THE EAST COAST OF HONSHU, JAPAN
5.0 2011/03/12 16:38:45 38.067 144.066 25.1 OFF THE EAST COAST OF HONSHU, JAPAN
5.0 2011/03/12 16:22:15 37.891 144.831 34.1 OFF THE EAST COAST OF HONSHU, JAPAN
5.7 2011/03/12 14:43:09 39.471 142.406 21.5 NEAR THE EAST COAST OF HONSHU, JAPAN
5.6 2011/03/12 14:35:00 35.784 141.660 24.4 NEAR THE EAST COAST OF HONSHU, JAPAN
5.3 2011/03/12 14:11:05 25.396 -109.652 12.1 GULF OF CALIFORNIA
5.8 2011/03/12 14:03:30 38.843 142.592 24.8 NEAR THE EAST COAST OF HONSHU, JAPAN
5.2 2011/03/12 13:57:12 36.439 141.926 24.2 NEAR THE EAST COAST OF HONSHU, JAPAN
5.3 2011/03/12 13:26:56 39.381 142.423 25.1 NEAR THE EAST COAST OF HONSHU, JAPAN
6.4 2011/03/12 13:15:42 37.261 141.175 37.5 NEAR THE EAST COAST OF HONSHU, JAPAN
5.8 2011/03/12 12:53:50 37.754 143.573 19.2 OFF THE EAST COAST OF HONSHU, JAPAN
5.7 2011/03/12 11:46:01 35.761 141.656 17.6 NEAR THE EAST COAST OF HONSHU, JAPAN
6.1 2011/03/12 10:53:31 39.075 142.352 24.9 NEAR THE EAST COAST OF HONSHU, JAPAN

reply to post by Hundroid


So, interestingly enough, TA and I were both right. Just differing definitions.

I was certainly expecting this development. I mean, the USGS report is still just the computer-generated report...do their seismologists work on weekends?

Also, I just wanted to mention that the PTWC has not updated their page yet even from the 7.9 as it was originally reported by the USGS. Look at the link:

ptwc.weather.gov...

So it's very possible this is true. With something this big, there is surely a lot of study on it continuing.

reply to post by CLPrime


I was wondering too if USGS seismologists are sick or just went fishing for the weekend challenging tsunami waves for fun...

Anyway I think the axis shift is just news for gullible people, just to sell newspapers.

In the wiki article about Richter scale there's instead a table showing Richter figures of famous earthquakes. I am a bit stunned by realizing how many major and great ones happened in the last ten years while much less in the past. Is there any other (maybe more reliable?) table of historical quakes?

Well, since I can't find this listed anywhere on the PTWC site, I have written to them to get confirmation. So we'll see soon hopefully if they respond.

Ok, I did receive a response, and have changed the thread title and updated the OP with new information.

But I can now confirm this is true, it is just that the first story was a bit inaccurate. USGS has yet to update, but it may soon. They may not. We'll see.

reply to post by CLPrime

Well, technically, it's a logarithmic scale...that's why a 9.0 is 10 times as powerful as an 8.0, and it means that a 9.1 is 1.6 times as powerful as an 8.9. Not quite 2, but close enough.

1.6 times bigger (on magnitude logarithmic scale) and 2.0 time stronger in energy release.

Terajoules

8.9 1,412,537.5
9.1 2,818,382.9