reply to post by soficrow
Your quoted source
Severe earthquakes in Haiti, Chile and now Japan have experts around the world asking whether the world's tectonic plates are becoming more active
-and what could be causing it.
First I am not aware of experts who are asking this. I am well aware of many media outlets and pseudo-experts asking this, but not once have I seen a
credible source making this statement.
Some scientists theorize that the sudden melting of glaciers due to man-made climate change is lightening the load on the Earth's surface,
allowing its mantle to rebound upwards and causing plates to become unstuck.
These scientists point to the historical increase in volcanic and earthquake activity that occurred about 12,000 years ago when the glaciers that
covered most of Canada in an ice sheet several kilometres thick suddenly melted.
The result was that most of Canada's crust lifted -and is still rising.
Let me re-phrase that for you. Global warming 'scientists' are attempting to point a finger at AGW as the source of the perceived (but not factual)
increase in earthquakes to further their agenda.
Geologists have long been aware of the effects of isostatic rebound which did indeed cause an increase in activity 12,000 years ago. What really
surprises me is that they have not blamed that on AGW yet. No doubt they are looking for a way.
Scientists have discovered that the accelerated melting of the Greenland ice sheet over the last 10 years already is lifting the southeastern part
of that island several millimetres every year.
Whoopy dog pooh. And the point is? Well the point is that they are trying to blame AGW for an increase in earthquakes because the glaciers are melting
and the land is lifting. The problem is that there is naff all in the way of earthquakes in Greenland. Here is the past 365 days:
2011-03-06 20:50:32, 73.060, 5.998, 4.6, 34.8, Greenland Sea
2011-03-06 20:50:27, 73.060, 5.870, 4.4, 2.0, Greenland Sea
2011-03-04 11:16:45, 73.123, 5.886, 4.7, 13.6, Greenland Sea
2010-10-29 18:28:32, 79.340, 3.760, 3.2, 10.0, Greenland Sea
2010-05-20 02:55:56, 73.460, 8.740, 4.3, 2.0, Greenland Sea
2010-05-16 20:23:04, 73.472, 7.225, 4.8, 29.8, Greenland Sea
2010-05-16 16:39:33, 73.407, 7.305, 5.2, 10.0, Greenland Sea
2010-05-16 15:29:02, 73.427, 7.496, 5.0, 10.0, Greenland Sea
2010-05-16 06:18:34, 73.460, 8.410, 4.2, 2.0, Greenland Sea
2010-05-02 09:17:27, 73.802, 8.719, 4.6, 10.0, Greenland Sea
2010-04-06 23:50:23, 73.775, 8.793, 5.3, 10.0, Greenland Sea
Mm, well that's another global warming theory down the drain then.
Other scientists, however, believe tectonic movements similar to the one that caused the Japanese quake are too deep in the Earth to be affected
by the pressure releases caused by glacier melt.
These scientists theorize that glacier melts could cause shallower quakes.
Andrew Hynes, a tectonics expert at Montreal's McGill University, said the issue is not so much the load shift on the Earth's crust, but rather the
increased fluid pressure in the fault that lubricates the rock, allowing the plate to slide.
"All earthquakes, except those produced by volcanic activity, are essentially the unsticking of faults," he said. In other words, if you pump fluid
into a fault, it can reduce the friction and allow the rock to slide.
Could the stress transfers and the added melt from glaciers inject more fluid into the rocks, creating earthquakes?
Well this has possibilities except for the last sentence although there is some evidence that rain can have an effect. (How can the melt water be
'injected'? I have serious doubts as to whether this was uttered by an 'expert'. I smell journalistic licence here.) But where are the earthquakes?
He added that the decompression from melting glaciers could cause an increase in volcanic activity by releasing the liquid rock and its explosive
Yes all the volcanoes in Greenland are going off because of this - NOT! Again I question the terminology. 'liquid rock'??
At the same time, the number and severity of earthquakes appear to have increased over the last 30 years in tandem with accelerating glacial
Um have they? I think I have already proved this is not the case. Where is the data to back up this completely ludicrous statement?
Some experts claim that jump can be explained by the increased number of seismograph stations -more than 8,000 now, up from 350 in 1931 -allowing
scientists to pinpoint earthquakes that would otherwise have been missed.
Yes there is definitely an element of truth in this for quakes under about 6.5 Magnitude.
Scientists have been tracking these powerful quakes for well over a century and it's unlikely that they have missed any during at least the last
Well that is good news. At least the figures I produced in the posts above should be accurate then! (If you define major quakes as 6.0+ then this
statement is supposition and unreliable. It is possibly valid for 6.5+)
The U.S. Geological Survey says there were 1,085 major earthquakes in the 1980s. This increased in the 1990s by about 50 per cent to 1,492 and to
1,611 from 2000 to 2009. Last year, and up to and including the Japanese quake, there were 247 major earthquakes.
There has been also a noticeable increase in the sort of extreme quakes that hit Japan. In the 1980s, there were four mega-quakes, six in the 1990s
and 13 in the last decade. So far this decade there have been two. This increase, however, could be temporary.
As I have demonstrated the number of quakes is not the important factor. Earthquakes are about the release of built up stress thus it is plain
stupidity to be quoting numbers against stress levels. I have also shown that this nonsense using numbers for Japan is NOT borne out by energy
Let me give an example of their warped thinking.
Year 1, 2 x 6.6 and 1 x 7.8 = 3 in total
Year 2, 4 x 6.3, 5 x 6.6 and 1 x 6.9 = 10 in total
OMG there has been a massive increase of major quakes. There were 3 in year 1 and that has increased by 233% to 10 in year 2.
Oh yeah? Now let us look at the energy released in that, i.e. the amount of stress that has been relieved
. We can even assume these all to be
in the one area if you like.
That actually means that in year 2 the energy release was only 13% of the value in Year 1.
So say we are looking at a big fault like San Andreas. Which would you prefer?
OMG there has been a massive increase
Phew that is a relief, the energy was much less this year
The 7.8 may destroy a city where as the ones under 7 may not - depending on many other factors.
You might, depending on the circumstances, say "looks as if very little pressure was released in the second year. It could be building up."
How could you justify that on the numbers? Would anyone believe you if you said "Mm, there were many more major earthquakes the second year. Looks as
if not much was happening. This could be a problem."
I have said it before, and I will say it again and continue saying it, the numbers are NOT significant.
Hynes said there is some evidence that one earthquake can snowball into another until the Earth's crust has adjusted to the new pressure
Typical bloody journalists. Got to have some doom. That really is a very poor way of stating this for a person who is supposed to be a tectonics
expert. I would love to know what the leading question was that elicited that response, if indeed he did actually say that. It is also rather curious
the term pressure transfers as we are talking about pressure release.
That article as far as I am concerned was full of disinformation and attempted sensationalism aimed directly at worrying the readership. Pretty
typical of the press in other words.
edit on 2/4/2011 by PuterMan because: (no reason given)