 | | From: | Michael Mcneil | | Subject: | Re: Finding Fault in Wrightwood | | Date: | Sat, 4 Dec 2004 08:20:48 +0000 (UTC) |
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 | "susan hough" wrote in message
news:9c32e257.0412031355.59ea561e@posting.google.com
> The new
> "bonus photo" on my Web site, http://www.findingfault.com/ , shows the
> tree ring signature of the 1812 San Andreas fault earthquake!
Appropos of nothing in particular I was wondering what factors cause the
notable changes in the way a tree grows rings.
Obviously climate differences, the cycles used to calibrate tree ring
dating.
Local water table changes as would probably occur in an area where the
ground is heaved up or down.
Local building and water abstraction requirements.
Felling other trees; planting other things.
Balance of the tree, as mentioned, the tree lost branches. Gravity will
affect the way the tree needs to produce branches. (Note the shapes of
trees growing on hills vs those on flat land.)
Covered in the above but not normally noticed even by tree huggers is
the effect of aerodynamics.
Trees and bushes in an untended coppice will form an overall curve to
minimise the effects that gales will have on a tree. The same way that
the individual trees grow out to maximise the light available to them.
Remove some and the environment is either better or worse, depending on
the competiton.
Have you got a full picture of the cross section and can you highlight
the rings involved please?
I believe (I can't back it up but) the way a tree pumps up water depends
on the twisting motion imparted by the wind on its branches.
--
Posted via Mailgate.ORG Server - http://www.Mailgate.ORG
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| | From: | Robert Flory | | Subject: | Re: Finding Fault in Wrightwood | | Date: | Sat, 4 Dec 2004 12:07:18 -0800 |
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"Michael Mcneil" wrote in message
news:5568e3900834d3a6725a34a1131c7060.45219@mygate.mailgate.org...
> "susan hough" wrote in message
> news:9c32e257.0412031355.59ea561e@posting.google.com
>
>> The new
>> "bonus photo" on my Web site, http://www.findingfault.com/ , shows the
>> tree ring signature of the 1812 San Andreas fault earthquake!
>
> Appropos of nothing in particular I was wondering what factors cause the
> notable changes in the way a tree grows rings.
>
SNIP
For a tree in the area of ground movement one could expect some serious
damage to the root system. This could possibly takes years to restore.
Bob
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| | From: | Michael Mcneil | | Subject: | Re: Finding Fault in Wrightwood | | Date: | Sun, 5 Dec 2004 08:12:23 +0000 (UTC) |
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| "Robert Flory" wrote in message
news:cot5dn$qe4$1@news.astound.net
> "Michael Mcneil" wrote in message
> news:5568e3900834d3a6725a34a1131c7060.45219@mygate.mailgate.org...
> For a tree in the area of ground movement one could expect some serious
> damage to the root system. This could possibly takes years to restore.
I can remember the xmas tree of a neighbour when I lived in a place
that had suffered from a sea flood.
The tree was rooted and planted out each year after xmas. Until the
flood came in February and turned all the needles brown but they kept it
for several years. One day faint traces of green at the tips of the
branches could be seen.
Very unusual.
--
Posted via Mailgate.ORG Server - http://www.Mailgate.ORG
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| | From: | susan hough | | Subject: | Re: Finding Fault in Wrightwood | | Date: | 5 Dec 2004 11:51:12 -0800 |
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| "Michael Mcneil" wrote in message news:...
> "Robert Flory" wrote in message
> news:cot5dn$qe4$1@news.astound.net
>
> > "Michael Mcneil" wrote in message
> > news:5568e3900834d3a6725a34a1131c7060.45219@mygate.mailgate.org...
>
> > For a tree in the area of ground movement one could expect some serious
> > damage to the root system. This could possibly takes years to restore.
>
> I can remember the xmas tree of a neighbour when I lived in a place
> that had suffered from a sea flood.
>
> The tree was rooted and planted out each year after xmas. Until the
> flood came in February and turned all the needles brown but they kept it
> for several years. One day faint traces of green at the tips of the
> branches could be seen.
The earthquake-induced innundation of trees, by either fresh or salt
water, allows another kind of tree-ring study. Up in Cascadia, some
of the earliest/most compelling evidence for the 1700 megathrust quake
came from
"ghost forests"--trees along the coast that had been innundated by sea
water and died, but whose trunks were still standing. And baldcypress
trees standing in Reelfoot Lake provide evidence of an abrupt creation
of the lake, because the trees can grow but not germinate in standing
water. Clever stuff, these tree-ring studies.
Susan
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| | From: | Skywise | | Subject: | Re: Finding Fault in Wrightwood | | Date: | Mon, 06 Dec 2004 00:16:16 -0000 |
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| hough@gps.caltech.edu (susan hough) wrote in
news:9c32e257.0412051151.7e3388ea@posting.google.com:
> The earthquake-induced innundation of trees, by either fresh or salt
> water, allows another kind of tree-ring study. Up in Cascadia, some
> of the earliest/most compelling evidence for the 1700 megathrust quake
> came from
> "ghost forests"--trees along the coast that had been innundated by sea
> water and died, but whose trunks were still standing. And baldcypress
> trees standing in Reelfoot Lake provide evidence of an abrupt creation
> of the lake, because the trees can grow but not germinate in standing
> water. Clever stuff, these tree-ring studies.
>
> Susan
I lived up in Bremerton Washington in 90-91 and had a chance to go
hiking on the outskirts of the Olympic Forrest. The place we went
to is called Lena Lake and was formed by a massive landslide that
blocked the river. You could still see the forest standing in the
lake.
Later on as my interest in seismology grew I learned that there are
dozens of these lakes in the area, all probably caused by the 1700
event.
It's amazing to think back on those memories and realize those
submerged trees have been there for 300 years.
BTW, Susan, I was watching a program on The Science Channel today
about 'earthquake storms' in which you made the little walk across
the San Andreas fault from the Pacific Plate to the North American.
Brian
--
http://www.skywise711.com - Lasers, Seismology, Astronomy
"He that would make his own liberty secure must guard even his
enemy from oppression." -- Thomas Paine
Sed quis custodiet ipsos Custodes?
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| | From: | susan hough | | Subject: | Re: Finding Fault in Wrightwood | | Date: | 4 Dec 2004 11:57:29 -0800 |
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| "Michael Mcneil" wrote in message news:<5568e3900834d3a6725a34a1131c7060.45219@mygate.mailgate.org>...
> "susan hough" wrote in message
> news:9c32e257.0412031355.59ea561e@posting.google.com
>
> > The new
> > "bonus photo" on my Web site, http://www.findingfault.com/ , shows the
> > tree ring signature of the 1812 San Andreas fault earthquake!
>
> Appropos of nothing in particular I was wondering what factors cause the
> notable changes in the way a tree grows rings.
>
Sometimes an answer is deceptively easy: the tree was growing almost
directly atop the main fault trace, so presumably when it moved
(abruptly) by 4-5 meters, it didn't bring 100% of its root system
along for the ride!
Susan
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