Increases in earthquake activity

[Brian]

Just one question.
Over the last few years has there been an increase in earthquake activity.
Please don't give me a lot of data that I may not understand.
Just a few lines of text that indicates Yes, No or Maybe is all I ask.

--
Regards Brian

[Skywise]

Brian <bcl...@es.co.nz> wrote in
news:1381603381373521915....@free.teranews.com:

Short answer: No. Well, maybe, but probably not. Then again... ?

Longer, better answer: The problem is with the short duration
of earthquake record keeping relative to geologic timescales.
The Earth is 4.5 billion years old and we only have detailed
records for maybe the last 50 years? (all quakes globally
down to mag 4.5 or so) That's not even a gnat's kidney stone
in a drop of its pee in the ocean, if that.

What I'm saying is, although there may be more quakes "in
recent years" compared to the last few decades, we don't
really know what that means in the grand scheme of things.
Perhaps this is just an uptick in activity that happens
from time to time. We don't know. We don't know what may be
the long term pattern over hundreds or even thousands of years.

Compare this to the weather (setting aside 'global warming').
Some years you get more rain than average. Some years are
hotter than average. There are fluctuations. But we've been
recording the weather far longer than we've been recording
quakes (in any detail) and thus can make a measured guess
as to the long term average. We can't yet do that for quakes.

Locally, that might be a different story. Paleoseismology
techniques (digging trenches across faults to examine slip
events) allows scientists to judge recent activity back
hundreds of years. For example, the southern San Andreas
is now known to have had 7 major events in the past 1100
years, with an average recurrence interval of about 180
years. It has been more than 300 years since the last event.
(scary, since I'm in it's area)

In another example, Parkfield has had ~mag 6 quakes in 1857,
1881, 1901, 1922, 1934, and 1966. This gives an average
recurrence interval of 21.8 years, meaning the next quake
should have occured in 1987 or 1988. It didn't happen until
2004, a gap of 38 years and almost 17 years 'late'.

So even when we do have some data, it's still difficult
to say.

Since quakes happen so infrequently, especially large ones,
we might need tens of thousands of years of data in order
to get a meaningful 'average' or trend of global rates.

Brian
--
http://www.skywise711.com - Lasers, Seismology, Astronomy, Skepticism
Sed quis custodiet ipsos Custodes?

[Brian]

Thanks Skywise.

I was meaning more in recent times for example comparing quakes in the 10
year period (1990 - 2000) to quakes from the 10 year period (2000 - 2010).
Has there been more earthquake activity in (2000 -2010) compared to (1990 -
2000)?

--
Regards Brian

[Don in Hollister]

>
>
>
> Thanks Skywise.
>
>
>
> I was meaning more in recent times for example comparing quakes in the 10
>
> year period (1990 - 2000) to quakes from the 10 year period (2000 - 2010).
>
> Has there been more earthquake activity in (2000 -2010) compared to (1990 -
>
> 2000)?
>
>
>
> --
>
> Regards Brian

Hi Brian. Since you didn’t give a magnitude range I did a search using the NEIC quake catalog for quakes of 6.0M and larger. Keep in mind some of the quakes listed are aftershocks from larger quakes. Hope this is what you’re looking for. Take Care…Don

FILE CREATED: Fri Nov 2 12:43:23 2012
Circle Search Earthquakes= 1496
Circle Center Point Latitude: 0.000N Longitude: 0.000E
Radius: 20000.000 km
Catalog Used: PDE
Date Range: 1990/01/01 to 1999/12/31
Magnitude Range: 6.0 - 9.9
Data Selection: Historical & Preliminary Data


FILE CREATED: Fri Nov 2 12:44:55 2012
Circle Search Earthquakes= 1765
Circle Center Point Latitude: 0.000N Longitude: 0.000E
Radius: 20000.000 km
Catalog Used: PDE
Date Range: 2000/01/01 to 2010/12/31
Magnitude Range: 6.0 - 9.9
Data Selection: Historical & Preliminary Data

[Brian]

Don in Hollister <don...@garlic.com> wrote:
>>
>>
>>
>> Thanks Skywise.
>>
>>
>>
>> I was meaning more in recent times for example comparing quakes in the 10
>>
>> year period (1990 - 2000) to quakes from the 10 year period (2000 - 2010).
>>
>> Has there been more earthquake activity in (2000 -2010) compared to (1990 -
>>
>> 2000)?
>>
>>
>>
>> --
>>
>> Regards Brian
>
> Hi Brian. Since you didn t give a magnitude range I did a search using
> the NEIC quake catalog for quakes of 6.0M and larger. Keep in mind some
> of the quakes listed are aftershocks from larger quakes. Hope this is

> what you re looking for. Take Care&Don

>
> FILE CREATED: Fri Nov 2 12:43:23 2012
> Circle Search Earthquakes= 1496
> Circle Center Point Latitude: 0.000N Longitude: 0.000E
> Radius: 20000.000 km
> Catalog Used: PDE
> Date Range: 1990/01/01 to 1999/12/31
> Magnitude Range: 6.0 - 9.9
> Data Selection: Historical & Preliminary Data
>
>
> FILE CREATED: Fri Nov 2 12:44:55 2012
> Circle Search Earthquakes= 1765
> Circle Center Point Latitude: 0.000N Longitude: 0.000E
> Radius: 20000.000 km
> Catalog Used: PDE
> Date Range: 2000/01/01 to 2010/12/31
> Magnitude Range: 6.0 - 9.9
> Data Selection: Historical & Preliminary Data

Thanks Don.

That shows an increase in earthquake activity.

--
Regards Brian

[Jack Campin]

>>> Has there been more earthquake activity in (2000 -2010) compared
>>> to (1990 - 2000)?

>> Hi Brian. Since you didn't give a magnitude range I did a search using
>> the NEIC quake catalog for quakes of 6.0M and larger. Keep in mind some
>> of the quakes listed are aftershocks from larger quakes.
>>

>> FILE CREATED: Fri Nov 2 12:43:23 2012
>> Circle Search Earthquakes= 1496

>> FILE CREATED: Fri Nov 2 12:44:55 2012
>> Circle Search Earthquakes= 1765

> That shows an increase in earthquake activity.

Only if you can prove there was no confounding factor that might get
more shocks recorded in the later decade. I can think of lots of
ways that might happen.

-----------------------------------------------------------------------------
e m a i l : j a c k @ c a m p i n . m e . u k
Jack Campin, 11 Third Street, Newtongrange, Midlothian EH22 4PU, Scotland
mobile 07800 739 557 <http://www.campin.me.uk> Twitter: JackCampin

[Skywise]

Jack Campin <bo...@purr.demon.co.uk> wrote in
news:bogus-B6A078....@four.schnuerpel.eu:

> Only if you can prove there was no confounding factor that might get
> more shocks recorded in the later decade. I can think of lots of
> ways that might happen.

Specifically, aftershocks.

When you have mag 9 quakes like Sumatra and Japan, you get lots of
aftershocks in large magnitudes that otherwise would be considered
large quakes in their own right.

[Brian]

Skywise <in...@oblivion.nothing.com> wrote:
> Jack Campin <bo...@purr.demon.co.uk> wrote in
> news:bogus-B6A078....@four.schnuerpel.eu:
>
>> Only if you can prove there was no confounding factor that might get
>> more shocks recorded in the later decade. I can think of lots of
>> ways that might happen.
>
> Specifically, aftershocks.
>
> When you have mag 9 quakes like Sumatra and Japan, you get lots of
> aftershocks in large magnitudes that otherwise would be considered
> large quakes in their own right.
>
> Brian

This century I seem to be getting a lot of news reports of earthquakes more
than I had over the last 10 years of the last century. 1990 - 2000. Also
the earthquakes reported are doing more damage.

--
Regards Brian

[Skywise]

Brian <bcl...@es.co.nz> wrote in news:1799422778373593612.319833bclark-
es.c...@free.teranews.com:

> This century I seem to be getting a lot of news reports of earthquakes more
> than I had over the last 10 years of the last century. 1990 - 2000. Also
> the earthquakes reported are doing more damage.

So is that a function of there being more earthquakes, or more
quakes being reported in the news?

Not all quakes make the news. Even big ones.

[data...@yahoo.com]

no, why would there be ? did someone bogie a fag ?

an interloper from field research in animal behavior/communications/language, I had thought EQ activity potentially increased, in some manner, in time approacing solstices where internal flow changed directions.

Flow does, maybe, and there's mention of that in SGE as an answer to the solstice idea but statistically reports are that no, there's no significant change approaching or leaving the time of solstice. The solstice time as a potential analogy for what your considering.

I predict earthquake activity or did until those GGH^&!!123XX at USGS changed the maps finding the assumed solstice efffect. The assumption works for prediction but not for statistics. It's not normal.

Notice your area fell several points on the 'nice place to live' charts.

[nos...@nospam.invalid]

"Brian" <bcl...@es.co.nz> wrote in message news:1799422778373593612....@free.teranews.com...

It doesn't matter how one quantifies it, the same advice is still true: the Sumatra
quake/tsunami killed almost a quarter million people, so most comparison charts
(of quake damage costs, fatalities etc) would be equally or even more skewed
toward that decade.

[Brian]

Bob Officer <bobof...@127.0.0.7> wrote:

> the increase in nonsignificant, over the excessively short time
> period selected.
>
> Do we need to re educate people into what is and isn't significant
> figures/over time periods?
>

I'm considering earthquakes that can do damage and not just moderate
shakes.

--
Regards Brian

[Weatherlawyer]

Everyone wants definitive answers in sentences of no more than one or
two words.

I think that there is a general increase in quaking, there is
certainly a biblical "Reporting of them from one place after another";
something unprecedented before the age of electronic communication.

But simultaneously, along with the development of electric cables came
industrialisation. Britain began to systematically overgraze every
pink portion of the world map from Victorian times on.

Rampant logging went on from the mid 20th century; something begun in
the 18th century in North America. A process that wiped out most of
the natural environment of Mid Western USA by 1930 with famously
disastrous results.

Something permitted in most European colonies on almost the same
scale, except there was not the same industrialisation in places like
Africa as there was in the USA.

Over hunting was matched by over fishing. And along with modern
trawling, came to widespread destruction of the sea beds of almost
every continental shelf. This is a landslide in tropical countries
where fishermen harvest fish for the aquarium market by dosing their
reefs with cyanide.

All of which means that mere Cat 2 storms can wreak havoc in
sophisticated countries and bring mass mortality in places like
Bangladesh.

All of the above would have almost no great statistical effect on the
world's averages, I imagine, except for the fast that Warm Poll
heating is now out of control.

The two greatest ocean gyres in the Northern Hemisphere have garbage
patches made up of buoyant debris from river and airborne plastic. So
far environmental wing-nuts haven't made the connection between these
dumps and glowballs.

They still believe that a modest increase in Carbon dioxide levels is
the cause of all our woes. I wonder what they will do when they wake
up.

Expect politicians to do something no doubt.

Which means we are all screwed.

Ah, well. T'was ever thus.
In Jesus' day the Roman Empire was taxing trees. Imagine the impact
that had on rivers in the days before dredgers were designed to keep
channels open to ports.

Slopes stripped of trees are prone to land-slides in years of floods.
(Every 4 years or so the planet gets seasons that are extra wet.
Search your own country's databases to see if this is so.) Landslides
along populated routes usually mean extra silt in nearby rivers.

And extra silt means a need for dredging, -or the abandoning of
capital cities. Something we can't imagine in this age but happened
fairly frequently to many once thriving cities in the past.

What we have instead, in this day and age is an increase in storms or
in their potency -which, coupled with land drainage, deforestation and
cleared river channels, means greater damage to sea coasts and
populated coastal regions inland.

Check out Google Maps for anywhere that landslides are reported, you
will see that main arteries are usually stripped bare of trees for a
number of miles either side of the road systems. It is the same with
regions subject to strip mining - with the same consequences.

The connection with earthquakes in all this?
Because tropical storms occur in still air regions above warm water,
they have more chance of becoming super-cyclones. For some reason, the
connection with quakes lies with the weather fronts these engender,

However it is impossible to state that quakes are more destructive
these days as there is too little data to play with. Are parallel
weather fronts more numerous these days?

If so then the number of large quakes will not be greatly affected
with modern accounting writing-off these related, subsequent,
consecutive aftershocks as inconsequential.

You pays yer munee an you takes yer choices.

[Skywise]

Bob Officer <bobof...@127.0.0.7> wrote in
news:0kpb98hnodnrq33mt...@4ax.com:

> sliding windows

You're gonna give the guy a mental BSOD with all the
technical statistics mumbo-jumbo. :)

BTW, Bob, loved the flashback moment with your tagline.

mmm...back to my Daft Punk meditations.....

[Skywise]

Bob Officer <bobof...@127.0.0.7> wrote in

news:6b7c98t1lb08j19k3...@4ax.com:

> Edvins was fun until he dwindled away. He did make people think.

Your quotation reminds me of someone else, in that he has
literally written 1000 word essays about why he doesn't have
the time to address the questions you put to him. A true
master of dismissive logic.

[Skywise]

Bob Officer <bobof...@127.0.0.7> wrote in

news:muie98hfe73jkqfa1...@4ax.com:

> Then he was involved in a Kooksuit...

It's been so long I don't recall any details of his departure.
I just remember he kept the group 'lively'.

Gosh, where did all the cool ones go? Like Don Quixote and
others? I guess all good things come to pass. :(