Saturday, March 12, 2011

Earthquakes, Our Environment and Economic Activities

The earthquake that struck northeastern Japan in March of 2011, even by modern seismic measures, and for a country in the most seismically active zone in the world, the Pacific Ring of Fire, was an unusually high one. It measured 8.9 on the Moment Magnitude scale - denoted usually as "8.9 M".

Though 80% of all earthquakes on planet earth occur in the Pacific subduction zone, there has been some evidence that frequency of earthquakes, since recording began, has been growing - due to increased documentation and occurence. There is also a growing concern that earthquakes measuring more than 7.5 M may be on the increase.

Lets look at the historical records from a reputed reliable global agency, that reports all earthquakes around the world with high accuracy and regularity - the United States Geological Survey (USGS), and see if increase in earthquakes and their magnitude is actually occuring and can be numerically captured.

I have used the USGS records that document and rank (for historical consequences), available at http://earthquake.usgs.gov/earthquakes/world/historical.php,
all the major earthquakes globally, to see any noticeable changes in frequency and severity in earthquakes, since 1995, around the world.

I used this official historical data, available to the public, to count the number of earthquakes above 6.0, 7.0 and 8.0 on the Moment Magnitude scale (both as absolute numbers and as percentages of the total number of quakes recorded). I report on the earthquake with the highest measure on the Moment Magnitude (MM) scale for each year, and the quake that caused the most damage and devastation - as the severity of a quake does not determine the level of damage and deaths suffered by a community. (The acuity of a devastation depends on a whole range of environmental and social variables: where the epicenter was located, how shallow the quake was, how densely populated are the areas near the epicenter, how old or poorly built the buildings are, how efficient and organized is the disaster rescue operation, etc.).

In 1995 there were four earthquakes measuring 6.0 or more on the MM scale.  Only one earthquake measured over 7.0. It was the one on Sakhalin Island - measuring 7.1 and killing 1,989 people. The one that caused the most fatalities was the Kobe, Japan earthquake. It measured only 6.9 M and killed 5,502 people.

In 1996 there was only one major earthquake that measured more than 7.5 M. It was the Andreanof Island quake, measuring 7.9, in Alaska.

In 1997 there were five earthquakes that measured above 6.0 M - four of which were above 7.0. The largest were the South Fiji Island and the East Coast Kamchatka quakes - each measuring 7.8 on the MM scale. The Northern Iran quake, measuring 7.3, left 1,567 dead.

In 1998 there were eight earthquakes above 6.0, six of which were above 7.0 M. The highest recorded was on Balleny Island Region - measuring 8.1. The one that caused the highest fatalities was between Afghanistan-Tajikstan border region – killing 4,000 people.

In 1999 there were thirteen earthquakes of historical consequence and all of them were above 6.0. Nine of those were above 7.0 in the Moment Magnitude Scale. The highest were the 7.6 earthquakes of Izmit, Turkey (that occured in August) and the one that followed in Taiwan (in September) - each killed 17,118 and 2,400 people respectively.

In 2000 there were seven earthquakes of historical consequence, with only one measuring below 6.0 M and one measuring below 7.0 M. All the rest (five of them) were above 7.0. The highest recorded was in Papua New Guinea - measuring 8.0. The one that caused the most fatalities was the Sumatra, Indonesia quake, in the 7-8 range, that killed 103 people.

In 2001 there were seven earthquakes above 6.0 M - five of them were above 7.0. The one that caused the most fatalities was the Gujarat, India quake that killed over 20,000 people and measured 7.8 on the Moment Magnitude scale. The highest was off the coast of Peru - it measured 8.4 M.

In 2002 there was a huge jump in the number of earthquakes (of historical consequence). There were forty-four earthquakes – of which more than 50% (twenty-four in absolute numbers) were above 6.0 M. The number of earthquakes above 7.0 stood at thirteen - which is nearly 30% of all the quakes for this year. The highest was recorded in Alaska - measuring 7.9, while the one that caused the most deaths, 1,000 in all, was in the Kush mountains of Afghanistan.

In 2003 there were sixty-nine earthquakes (69!) of historical consequence (according to USGS). Of these thirty-nine (nearly 57%) were above 6.0 - thirteen of which measured above 7.0 M. This means that nearly 19% of the total earthquakes recorded measured above 7.0 M. The largest one was on Hokkaido island of Japan - measuring 8.3. The one that caused the most fatalities was the 6.6 earthquake in Southeastern Iran. It killed 31,000 people.

In 2004 forty-eight earthquakes were reported by USCS as of historical consequence. Thirty-five were above 6.0 on the MM scale - which approximates to 73% of all quakes of consequence for the year. Thirteen of these were above 7.0 - which is 37% of all quakes measuring above 6.0 on the MM scale. This is nearly double the number that was recorded the previous year. The highest two were the 8.1 earthquake on North Macquarie Island and the 9.1 earthquake near Sumatra island of Indonesia. The latter produced a deadly tsunami that killed 227, 898 people across several countries in Southeast and South Asia.

In 2005 there were forty-nine earthquakes of historical consequence, of which thirty-five were above 6.0 - approximately 71% of the earthquakes for this year. There were eleven quakes above 7.0 - which is 31% of all quakes measuring more than 6.0. What is even more intriguing is that five of the quakes recording 7.0-and-above on the Moment Magnitude scale were above 7.5. That is more than 40% of the quakes that record above 7.0 were now recording above 7.5 M - a deadly number for many communities around the world. The highest was the 8.6 earthquake in Northern Sumatra, Indonesia - again, that killed 1,313, while the worst, in terms of number of fatalities, was the Pakistan earthquake that killed 86,000 people.

In 2006 there were thirty-three earthquakes of historical consequence, of which twenty-six of them were above 6.0 - nearly 79% of the total quakes. Of these ten were above 7.0  - which is about 39% of all quakes measuring 6.0 M or more. For the first time there were two quakes, reported by the USGS, that were above 8.0. This means that 6% of the total quakes, and 8% of all quakes above 6.0, were now recording at 8.0 M and above. The highest was the 8.3 earthquake on Kuril Islands, and the worst was the Java, Indonesia earthquake that killed 5,749 - though it only recorded 6.3 on the Moment Magnitude scale.

In 2007 there were fifty-four (54) earthquakes recorded as historically consequential, with forty-nine of them above 6.0 on the Moment Magnitude scale. This means 91% of the quakes recorded were now above 6.0 . This is a huge spike from the 60%-75% just few years ago. Of the total ten quakes above 7.0 M four were above 8.0 M. This means that nearly 40% of the total quakes measuring 7.0 or more were now recording above 8.0 M. (The four earthquakes at the highest range were: the 8.0 earthquake near Central coast Peru, 8.1 earthquakes on East of Kuril Island, another 8.1 earthquake on the Solomon Islands, and a 8.5 earthquake on Southern Sumatra. The deadliest was the Peru quake that left more than 500 dead).

In 2008 there were forty-one earthquakes identified as of historical consequence. Of these thirty-five are recorded as being 6.0 or more - which is 84% of the total quakes. Twelve of these were above 7.0 M – which is 30% of the total quakes for the year. The highest recorded was in Eastern Szechuan province of China, measuring 7.9, and killing 87,587. The second highest measured 7.7 on the Moment Magnitude scale on the Sea of Okhotsk.

In 2009 there were sixty-six earthquakes (66) identified as historically important by the  USGS. Fifty-two recorded above 6.0 on the MM scale - which is 79% of the total quakes (reported by the USGS as historically consequential). Thirty-five of these measured between 6.0 and 7.0, sixteen between 7.0 and 8.0, and one above 8.0. This means that early 33% of the total quakes, one-third, that measured above 6.0 now recorded above 7.0 M. The highest, measuring 8.1, occurred on Samoa Islands and killed 192 people. The one that caused the maximum fatalities was the 7.5 Sumatra earthquake. It killed 1,117.

In 2010 there were fourteen earthquakes of historical consequence with thirteen of them recording above 6.0 M. That is 93% of the total quakes reported for this year (by USGS) recorded above 6.0 on the Moment Magnitude scale. Of this eight of them were between 7.0 and 8.0, and one above 8.0 M. Now 50% of all quakes measuring above 6.0 M now record above 7.0 M. The highest was the off-shore Chile quake that measured 8.8 on the MM scale and killed 577 people. The most devastating was the Haiti quake - that measured only 7.0 but killed more than 222,000 people. The next major one was the Southern Qinghai, China quake - measuring 6.9 and killing 2, 968.

In 2011, though the year is not over, the highest recorded earthquake was the one off of northeastern coastal Japan that measured 8.9 on the MM scale. It has killed approximately 2,000 people (though the full death toll, as of March 12, 2011, is yet to ascertained).

Without question there has been a doubling, and sometimes a tripling, of earthquakes measuring above 6.0 on the Moment Magnitude scale in the last ten years (partly due to better recording and reporting). Sometimes as much as 70 to 80 percent of all quakes measured were recording above 6.0 M, while nearly half of those above 6.0 were now recording over 7.0 M.

What is intriguing is that the number of quakes measuring more than 7.0, the kind that causes the most damage in many developing countries, have nearly doubled or tripled in the last ten years...with an additional increase in the number of quakes measuring 8.0 and above  - an extremely rare event.

Environmentalists worry that certain human activities, like mining, drilling, new technologies that attempt to extract minerals and oil at depth of two, three or four miles underground or underwater (where geological plates can be fragile), and innovative techniques that can fracture, or fract (a specific technique in mining and drilling), rocks and other underground materials with high pressure and chemicals, may be contributing to higher numbers of tremors and earthquakes – both in severity and frequency.

There is also an additional concern that as more countries attempt to test their nuclear technology – for nuclear energy and/or for military weapons - lot of controlled explosions (underground, underwater and close to remote islands on the Pacific or the Atlantic) might be contributing to, if not causing, more earthquakes...and possibly producing more severe quakes (above 7.5 on the Moment Magnitude scale).

Testing these concerns and theories is challenging. If development has to continue around the world in a meaningful and a safe manner, without hurting people and communities for whom sustainable development is necessary, while enforcing responsible economic actions on many rich countries, then technologies designed, modified, improved, expanded and implemented by scientists, businesses and corporations, have to be fully investigated and evaluated for public safety – both short and long term.

What exactly is the relationship between earthquakes, that are increasing in frequency and intensity around the world as the USGC chart itself reveals, and human activities?

What is it our leaders, communities, businesses, researchers and governments are doing, secretly or openly, or not doing, that might be contributing directly or indirectly to tremors, shakes and earthquakes all over the world...some of which can prove to be devastating?

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