Tag Archives: earthquakes

International, U.S.

Magnitude 5+ earthquakes increasing? Several 7+ quakes so far for April 2013!

20 April 2013 (02:02 UTC-07 Tango)/09 Jumada t-Tania 1434/31 Farvardin 1391/11 Bing-Chen (3rd month) 4711

There has been several magnitude 7 earthquakes around the world in just the past three weeks.

The USGS uses a modified type of richter scale magnitude system.  They tried to clear up confusion a few years ago with a press release, but I think it just made things more confusing.

Most western media are using USGS magnitude readings when they report earthquakes, but, several countries have created their own magnitudes that do not match USGS magnitude reports.  I am presenting USGS magnitudes.

The following are the 6 to 7+ magnitude quakes for April, so far:

On 20 April 2013 Sichuan, China, was hit by a 6.6 quake, followed by four 5 quakes.  Reports say at least 152 killed, more than 3000 injured!  The Chinese are calling the initial quake a 7+ magnitude.

Russian Kuril Islands (on the Pacific Ring of Fire) were hit with a 6.1 magnitude quake, followed by a 5.3 quake.

On 19 April 2013, again the Russian Kuril Islands, hit with a 7.2, then a 5.7.  The Kuril Islands have been experiencing many magnitude 5 and 6+ quakes since the beginning of this Gregorian year.

For more example of how different quake reports are used by different countries, on 18 April 2013, Japanese officials reported a 7 magnitude quake off the coast of northern Japan. However, the USGS did not report such a quake.  It is possible that the Kuril Islands 7.2 quake reported on early 19 April by USGS is the same quake that Japan claimed on the 18th.  Japan and Russia both have claims to some of the Kuril Islands.

On 16 April 2013, a 7.8 quake hit along the Iran-Pakistan border.  At least 40 people killed, mainly on the Pakistani side.

Papua New Guinea (on the Pacific Ring of Fire) 6.6 quake.

On 14 April 2013, again Papua New Guinea hit with 6.6 quake.  The island country has also been experiencing many magnitude 5+ quakes.

06 April 2013, Indonesia (Pacific Ring of Fire) a 7 quake.

From 01 April to 20 April 2013 there have been at least seven magnitude 6+ quakes.  For all of April 2012 there were ten magnitude 6+ quakes (which included two 8+ quakes near Sumatra on the Pacific Ring of Fire).  We have a little under a week and a half left for April 2013, will mother Earth break last years April numbers?

By the way, officials in San Francisco, California, just passed new earthquake safety rules.  The new law forces owners of wooden framed multi-story buildings to reinforce the lower walls and to help distribute the weight of the building more evenly on the frame.  It’s estimated it will cost property owners $60000 to $130000 USD per building.  The law comes after years of study by seismologists.

International, Technology, U.S.

Pacific Ring of Fire Seismic Events: 2012 already shaping up to be big?

In past postings I reported on what appears to be the average number of magnitude 6.5 or greater earthquakes that hit the Pacific Ring of Fire.

In going through the USGS’s Significant Earthquakes of the World, all the way back to 1999, it seems the Pacific Ring of Fire has about 50 per year.

The Pacific Ring of Fire involves not only the Pacific Plate, but the Nazca Plate, the Antarctic Plate, Cocos Plate, Juan de Fuca Plate, North American Plate, South American Plate, Scotia Plate, Filipino Plate, Eurasian Plate and Australian Plate, whew!

Well, from January 1 to February 12, 2012, there have already been seven “significant” earthquakes involving the plates of the Pacific Ring of Fire.  In fact, so far, the only significant quakes for 2012 have been the seven around the Pacific Ring of Fire!

What about earthquakes in general?  If you look at the USGS’s list of quakes from January 13 to February 4, 2012, the overwhelming majority are around the Pacific Ring of Fire.  I counted at least 453 reported earthquakes around the Pacific Ring.

Most of the quakes are hitting Japan (with the most), California, Alaska, Mexico, Chile, countries on the Filipino Plate (like Indonesian islands getting hit almost as much as Japan), New Zealand and Vanuatu.

Vanuatu is a Southwestern Pacific Island north of New Zealand.  Since the beginning of February it’s getting hit almost daily with quakes ranging from magnitude 4 to 5.

International, Technology, U.S.

Pacific Ring of Fire Seismic Events part 5 Largest Deadliest update

Since I posted part 4 of Pacific Ring of Fire Seismic Events, the United States Geological Survey added one more quake to it’s “Largest and Deadliest Earthquake” list; the March 11 earthquake near Japan.

But have there been more large quakes this year, not qualifying for the USGS title of “Deadliest”, but still large, and more than normal?

According to the USGS “Significant Earthquakes of the World” list, so far this year there have been 49 magnitude 6.5, or greater quakes around the Pacific Ring.  The majority of those being near Japan.  There’s still three months left to go for 2011.

In 2010 the USGS recorded about 57 M6.5+ quakes around the Pacific Ring.  About 50 M6.5+ quakes took place in 2009.  So in the past three years it looks like about 50 M6.5+ Pacific Ring quakes per year are the norm.

I went back to “Significant Earthquakes of the World 1999”, and counted about 53 M6.5+ Pacific Ring quakes.  So, without doing more detailed research, it looks like the number of “significant” quakes around the Pacific Ring is about 50 per year, and seems to be normal.  Unless we get a sudden boost in quake activity within the next three months, it looks like 2011 will be another normal year.

What about the number of “deadliest” earthquakes, is there an upward trend?  It doesn’t seem so.  Looking at the USGS “Largest and Deadliest Earthquakes by Year 1990-2011” list, we average about one or two per year, and that’s all over the world not just the Pacific Ring.  The USGS determines the “largest and deadliest” by a combination of magnitude intensity and the number of people killed.

However, I noticed an interesting trend regarding when those “largest” deadly quakes happen; most of the dates are from Autumn to Spring, with the minority happening during Summer.  We are closer to the Sun from Fall to Spring, mmmm.

 

Fukushima, International

Ring of Fire Seismic Events part 4 Largest Deadliest

The United States Geological Survey has vast data on earthquakes.  I looked at their “Largest and Deadliest Earthquake” list, which spans 1990 to 2011.

I looked at just those quakes on the Pacific Ring of Fire. I was looking to see if there was an increase in frequency and/or magnitude over the past 21 years.

There were a total of 31 “largest/deadliest” earthquakes on the Pacific Ring of Fire. The magnitudes ranged from 6.3 to 9.1 Richter scale. It looks like the amount of activity is spread evenly over the past 21 years, but it’s deceptive.  From year to year the pattern of activity is interesting.

1990 one,  1991 two, 1992 one, 1993 one, 1994 two, 1995 three, 1996 one, 1997 two, 1998 one, 1999 one.  At this point it looks like there is a loose pattern; 1/2/1/1/2/3/1/2/1/1.

2000 two, 2001 one, 2002 one, 2003 one, 2004 two, 2005 one, 2006 two, 2007 two, 2008 zero, 2009 two, 2010 one, 2011 two.  The pattern is different; 2/1/1/1/2/1/2/2/0/2/1/2.

Where the most quakes hit changes as well.  In the 1990s Japan was hit by one large/deadly quake.  From 2000 to 2011, Japan has been hit by two large/deadly quakes.  But check out Indonesia. In the 1990s the Indonesian islands were hit with two large/deadly quakes.  From 2000 to 2010 the Indonesian islands suffered six large/deadly quakes.  On the Americas side of the Pacific Ring it looks like quakes are more evenly spread out over the years.  From 1990 to 2011 a total of eight large/deadly earthquakes were spread from Alaska to Chile.

What is clear is that the activity is more frequent, and stronger, on the Asian side of the Pacific Ring (probably because that’s where the Pacific plate slams under the Eurasian plate).  But that’s no reason not to prepare, if you don’t live on the Asian side.

Note: The Japanese islands and the Indonesia islands are affected by several plates. Japan sits on the Eurasian plate, which is being hit by the Pacific plate and Philippine plate.  Indonesia straddles the Eurasian and Philippine plates, which are getting hit by the Pacific plate.

 

 

U.S.

Bicentennial of New Madrid Quakes

Throughout 2011 and 2012, in the central U.S., there will be events held for the 200th Anniversary of the great 1811 and 1812 New Madrid earthquakes.

The New Madrid Seismic Zone stretches from west of Memphis, Tennessee into southern Illinois.  The 1811 and 1812 earthquakes were between magnitude 7-8 (Richter scale), with hundreds of aftershocks. They were felt down to the Gulf of Mexico, and north to Canada.

http://newmadrid2011.org/

International

Japan still being hit by aftershocks, Iran getting hit by quakes

During live NHK broadcast, early today in Japan, they were hit by an aftershock, which caused the anchor to apologize for it.

Today Iran announced that two mild quakes hit in quick succession in southeastern Iran.  Iran has several major fault lines running through the country, producing many major quakes.

The worst in recent times hit Bam in southeastern Kerman province in December 2003, killing 31,000 people.  In December 2010, southeastern Iran was hit by a 6.5 quake.  Fault lines in southeaster Iran have been highly active for the past 10 years.