HDTenEightyP/NetNews huggingface dataset:
From: tffreeba@indyvax.iupui.edu
Newsgroups: sci.geo.geology
Subject: Re: Question about Earth's magnetic poles
Date: 8 Jan 93 23:37:40 -0500

In article <145527@lll-winken.LLNL.GOV>, hudek@polaris.llnl.gov (David Hudek) writes:
> <||>
> 
> Pardon my ignorance...
> 
> I was reading a book the other day in which it was claimed there was
> (unspecified) geological evidence that the Earth's magnetic poles had
> shifted rather dramatically in the past. It was rather vague
> and offered no details/references so I tend to disbelieve it, but thought
> of what a wonderful resource the "net" is... can anyone confirm/deny
> the assertion? (sci.geo.geology seemed like an appropriate newsgroup; 
> my apologies if not).

I think the basic problem we have here is what you mean by shifted.  As
others have pointed out there are two different ways that the poles "move."
One is apparent polar wandering as seen in the orientation of magnetic 
materials that is in rock that cooled in the past.  There is a simple
discussion of this in Harold Levin's _The Earth Through Time_ 1988,
Saunders University press, pp. 232-233.

The other way is magnetic reversal where the north pole becomes the south pole
(magnetically) and visa versa.  There is a simple discussion of this in
Plummer and McGeary's _Physical Geology_ 1991, Wm. C. Brown Publishers, 
pp. 385-386.  I read somewhere a speculation that there may be a period of a
1000 years when there are no poles during one of these reversals.  Must make
the Homing Pigeons nuts!   BTW Plummer and McGeary say we are 200,000 years
overdue for a reversal.

Thomas Freebairn
| I have no idea if my opinions are the same as Indiana University - Purdue
University at Indianapolis or not.  I never thought to ask... I tend to
doubt it though.|

P.S. Did I dream that 1000 year period without poles stuff?  If not, does that
mean that the whole Earth magnetic field goes bye-bye?  That sounds like it
could be nasty. TFF
Xref: sparky sci.geo.geology:2711 sci.image.processing:1540 comp.graphics:13654
From: jjohnson@hindmost.lpl.arizona.edu (Jeff Johnson x8605)
Newsgroups: sci.geo.geology,sci.image.processing,comp.graphics
Subject: (Geologic) Unit Mapping Software?
Keywords: unit mapping, Photoshop
Date: 11 Jan 93 21:28:42 GMT
Followup-To: sci.geo.geology
Distribution: usa
Organization: Lunar & Planetary Laboratory, Tucson AZ.


I'm interested in UNIX-based and/or Mac-based graphical
software that can be used to produce unit maps, specifically geologic
unit maps.  In essence this requires the ability to draw boundaries
on images to define areas that can then be filled in with a color 
and/or gray-level (DN number).
	Adobe Photoshop on the Mac fulfills most of these requirements.
However, if one wishes to map a unit that exists totally inside another,
the filling-in of the larger unit obscures the image information of the
smaller unit.  I anticipate that this is a problem with other graphics
packages as well.  One seemingly has to perform tedious patching (e.g.,
addition of images which contain zeroes everywhere except for a single
mapped unit)--which is prone to other errors.

	Any advice or recommendation on computer-assisted unit-mapping
is much appreciated.

Jeff Johnson
PIRL/LPL
UAZ
From: hudek@polaris.llnl.gov (David Hudek)
Newsgroups: sci.geo.geology
Subject: Question about Earth's magnetic poles
Date: 8 Jan 93 23:18:16 GMT
Organization: Lawrence Livermore National Labs, Livermore CA
Originator: hudek@roxanne.llnl.gov

<||>

Pardon my ignorance...

I was reading a book the other day in which it was claimed there was
(unspecified) geological evidence that the Earth's magnetic poles had
shifted rather dramatically in the past. It was rather vague
and offered no details/references so I tend to disbelieve it, but thought
of what a wonderful resource the "net" is... can anyone confirm/deny
the assertion? (sci.geo.geology seemed like an appropriate newsgroup; 
my apologies if not).

Thanks in advance,
dave h
djh@llnl.gov

< std. disclaimer: these are personal opinions only >
< I do not speak for any organization >
Xref: sparky sci.geo.geology:2689 ca.earthquakes:1533
From: rich@boreas.whoi.edu
Subject: Re: Question about Earth's magnetic poles
Organization: Woods Hole Oceanographic Institution
Date: Sat, 9 Jan 93 01:31:50 GMT

In article <1993Jan9.000819.18360@unocal.com> stgprao@st.unocal.COM (Richard Ottolini) writes:
>In article <145527@lll-winken.LLNL.GOV> hudek@polaris.llnl.gov (David Hudek) writes:
>><||>
>>
>>Pardon my ignorance...
>>
>>I was reading a book the other day in which it was claimed there was
>>(unspecified) geological evidence that the Earth's magnetic poles had
>>shifted rather dramatically in the past. It was rather vague
>>and offered no details/references so I tend to disbelieve it, but thought
>>of what a wonderful resource the "net" is... can anyone confirm/deny
>>the assertion? (sci.geo.geology seemed like an appropriate newsgroup; 
>>my apologies if not).
>
>A frequently asked question :-)
>
>Until the late 1960s it was not clear that either poles or the earth's surface shifted-
>both hypothesis had data- but after the plate tectonics the preponderance of evidence is
>best eplained by the earth's surface moving rather than the magnetic poles.


Ummm...this may not be very clear. Consider a chunk of molten rock. As
it cools and hardens, crystals will form aligned with the local
magnetic field. At crustal spreading centers (almost all under the
ocean), new rock is being formed continously, and the age of that rock
wil increase with distance away from the spreading center.
Lo-and-behold, one can find near these spreading centers, bands of rock
of the same age magnetized in the same direction, a direction which
changes numerous times with age (distance from the spreading center).
And the changes are pretty sudden (geologically speaking).

--
Rich Pawlowicz ----------------- INTERNET: rich@boreas.whoi.edu
Woods Hole Oceanographic Institution
"Home of the 99 cent squid burger (cheese extra)"
--------------------------------------------------------------
From: stevep@asi.com (Steve Pendleton)
Newsgroups: sci.geo.geology
Subject: "new" faults
Date: 5 Jan 93 00:56:09 GMT
Article-I.D.: asi.1993Jan5.005609.17421
Organization: Adaptive Solutions, Inc.,  Beaverton Oregon

I read a popular article that says the Landers event was on 
a "completely new" fault. It was ambiguous whether this meant 
"it was entirely absent before the event" or "it was clearly 
already there, but was previously unknown."

The latter must be far more likely, but every fault must have
a first event. (Or at least every first event must have a fault.)
Are there any cases -- Landers or otherwise -- of faults that seem 
to have their entire displacement from an observed event? 

Comments? Speculation? References?

Steve Pendleton                         Voice:  503-690-1236
Technical Writer                        Fax:    503-690-1249
Adaptive Solutions, Inc.                Internet: stevep@asi.com
1400 NW Compton Drive
Beaverton, Oregon       97006

Disclaimer: I deny everything and demand proof.
Newsgroups: sci.geo.geology
From: stgprao@st.unocal.COM (Richard Ottolini)
Subject: Re: Question about Earth's magnetic poles
Organization: Unocal Corporation
Date: Sat, 9 Jan 1993 00:08:19 GMT

In article <145527@lll-winken.LLNL.GOV> hudek@polaris.llnl.gov (David Hudek) writes:
><||>
>
>Pardon my ignorance...
>
>I was reading a book the other day in which it was claimed there was
>(unspecified) geological evidence that the Earth's magnetic poles had
>shifted rather dramatically in the past. It was rather vague
>and offered no details/references so I tend to disbelieve it, but thought
>of what a wonderful resource the "net" is... can anyone confirm/deny
>the assertion? (sci.geo.geology seemed like an appropriate newsgroup; 
>my apologies if not).

A frequently asked question :-)

Until the late 1960s it was not clear that either poles or the earth's surface shifted-
both hypothesis had data- but after the plate tectonics the preponderance of evidence is
best eplained by the earth's surface moving rather than the magnetic poles.
Newsgroups: sci.geo.geology
From: rel@mtu.edu (Robert Landsparger)
Subject: lat/lon to utm
Organization: Michigan Technological University
Distribution: na
Date: Sat, 9 Jan 1993 21:42:46 GMT

Looking for the math on how to transfer lat/lon to UTM.  or source
to a fortran subroutine.  Like to use this on a sun.

Many thanks,
	Bob
--
-- 
= Robert E. Landsparger, rel@mtu.edu
= Department of Geology  - OFFICE (906) 487-2167 / FAX 487-3371
= My comments do not represent those of my employer.
From: stead@skadi.CSS.GOV (Richard Stead)
Newsgroups: sci.geo.geology
Subject: Re: Earthquakes
Keywords: Major quakes increasing?
Date: 5 Jan 93 17:59:14 GMT

In article <1993Jan4.201801.4090@relay.nswc.navy.mil>, snorthc@relay.nswc.navy.mil (Stephen Northcutt - K31) writes:
> I went by the research section, and looked at an almanac (disasters and
> major quakes)  if the almanac is correct, most (by a humungeous majority)
> major quakes have occured this century.  Is this possible?  Or is this a
> function of better data recording?

Exactly.  Actually, it is a function of having seismometers at all.  It
is very difficult to determine the magnitudes of quakes that predate the
era of instrumental seismology.  In addition, a lot of big quakes just happen
to occur at places no one lives.  For example, just a few years ago, a very
large quake occurred along the Aleutians - the largest over a 3 year period.
Not a single human being in the world felt it.  Of course, it was well-recorded
seismologically.  Paleoseismology has been used to study quakes on some
faults over the past 10,000 years or so.  The evidence shows that quakes
occur relatively uniformly throughout time.

The best evidence that quakes are uniform is the uniform rate of movement
along faults.  Several features along the San Andreas can be dated.  When
the distance between them is measured, it shows that the movement averaged
over 5 million years is the same as the movement averaged over the past
few hundred.  Since this movement is produced in earthquakes, the earthquakes
must have been relatively uniform throughout time as well.


--
Richard Stead
Center for Seismic Studies
Arlington, VA
stead@seismo.css.gov
From: stead@skadi.CSS.GOV (Richard Stead)
Newsgroups: sci.geo.geology
Subject: Re: Plate tectonics of NW Alaska and E Siberia
Keywords: Plate tectonics  Bering Strait
Date: 7 Jan 93 21:34:08 GMT

In article <1993Jan7.184514.11717@netcom.com>, markc@netcom.com (Mark Conover) writes:
> I'm interested in the tectonic history of the Bering Strait
>  region in NW Alaska.  From the references I've checked, the
>  North American plate collided with the Eurasia plate 300
>  million years ago. Yet the area has no large upthrust

This seems incorrect from my knowledge.  The most recent collision between
Alaska and Asia would have been in the Cretaceous, about 125 Ma.  A large
ocean basin between them that existed in the Triassic needed to be closed.
I don't have recent references, but a look at

Churkin and Trexler, 1980, Circum-Arctic Plate Accretion - Isolating Part
of a Pacific Plate to Form the Nucleus of the Arctic Basin, Earth and
Planetary Science Letters, 48:356-362

should help.

You have picked one of the most difficult areas in the world to unravel
tectonically.  There is still some debate over the geometry of the present
plate boundary and how the North American/Asian plate boundary meets the
Pacific Plate.


--
Richard Stead
Center for Seismic Studies
Arlington, VA
stead@seismo.css.gov
Newsgroups: sci.geo.geology
From: peterl@tone.whoi.edu (Peter Lemmond)
Subject: Re: lat/lon to utm
Reply-To: peterl@tone.whoi.edu
Organization: Woods Hole Oceanographic Institution
Date: Mon, 11 Jan 93 18:38:40 GMT

Check out the "proj" package from USGS. This has got forward and
inverse transformation for all sorts of projections. Very accurate,
very "Unixy", etc.

From the README:


proj-?.?.tar.Z  Cartographic projection software.  Includes program
                proj (AKA invproj) that provides forward projections for
                about 70 cartographic projections and inverse conversions
                for more that 50% of the forward procedures.  Script
                procedures are provided for State Plane Coordinate System
                (SPCS) conversions to and from geographic coordinates.
                Also included is a forward/inverse geodesic program for an
                elliptical earth.
        Reference: "Cartographic Projection Procedures for the Unix
                Environment--A User's Manual", G.I.Evenden, USGS Open-File
                Report 90-284, 1990, 63p.


Available via anon ftp from charon.er.usgs.gov.

Peter Lemmond
Woods Hole Oceanographic Institution
From: anne@cco.caltech.edu (Anneliese Lilje)
Newsgroups: sci.geo.geology
Subject: Re: "new" faults
Date: 10 Jan 1993 03:35:57 GMT
Organization: California Institute of Technology, Pasadena
NNTP-Posting-Host: sandman.caltech.edu

In article <1993Jan5.005609.17421@asi.com> stevep@asi.com (Steve Pendleton) writes:
>I read a popular article that says the Landers event was on 
>a "completely new" fault. It was ambiguous whether this meant 
>"it was entirely absent before the event" or "it was clearly 
>already there, but was previously unknown."
>The latter must be far more likely, but every fault must have
>a first event. (Or at least every first event must have a fault.)
>Are there any cases -- Landers or otherwise -- of faults that seem 
>to have their entire displacement from an observed event? 
>Comments? Speculation? References?


The Landers Fault (tm) is a fault that is located within the Landers
Rupture Zone (everything that broke during the Landers Event). It
is a fault that has not previously ruptured. Rupture to the north and
South of the Landers Fault (tm) was along faults that were mapped
and had ruptured previously.

anne

Newsgroups: sci.geo.geology
From: su@flint.geology (Liqiang Su)
Subject: Seismic Data Analysis Code
Reply-To: su@flint.geology
Organization: Yale University
Date: Mon, 4 Jan 1993 17:35:06 GMT

Can anybody tell me if there is a IBM PC version of SAC?  



Newsgroups: sci.geo.geology
From: chenm@newton.ccs.tuns.ca (Ming chen)
Subject: How to access EPA through internet/bitnet ?
Date: Wed, 6 Jan 1993 20:37:41 GMT
Distribution: sci.geo.geology
Organization: Technical University of Nova Scotia, Halifax, N.S.


Hello, all

Is there any way I can access EPA BBS (for example CEAM) through
----------------------------------------------------------------
internet/bitnet ?
-----------------


Thanks for your help.

/ming


Email: chenm@tuns.ca


Newsgroups: sci.geo.geology
From: puchting@phobos.sscl.uwo.ca (R. Puchtinger)
Subject: BALANCE source code
Reply-To: puchting@phobos.sscl.uwo.ca (R. Puchtinger)
Organization: University of Western Ontario
Date: Wed, 6 Jan 1993 21:41:58 GMT





Could somebody e-mail source code for the USGS hydrochemistry program BALANCE to me?  I would appreciate a version compatible with either UNIX f77, VAX fortran, or the Microsoft fortran compiler.  Alternatively, I wonder if there is an anonymous FTP site with hydrochemical modeling software around.

	Thanks, 
		Rolf
From: smckenna@slate.mines.colorado.edu (MCKENNA SEAN ANDREW)
Newsgroups: sci.geo.geology
Subject: Grad Coursework Survey
Date: 11 Jan 93 15:11:14 GMT
Distribution: usa
Organization: Colorado School of Mines


  I have been deputized by our new department head to
look into course load requirements for MS and PhD 
degrees in earth science depts. around the country.
    Here at CSM we have 30 hours (10 standard
classes on the semester system) of coursework beyond
an MS for a PhD. 12 of those hours have to be grad
level courses in a minor dept. and 4 to 9 of them
are taken to fill departmental requirements within
geology/geological engineering.
    Some of us think the coursework requirements are 
excessive, especially when hearing from friends at 
schools with virtually no required courses, and are 
trying to get things changed.
    If you could please take a minute to fill out
the enclosed survey and e-mail it back to me I 
would appreciate it, only up-to-date info please!
If I get a good response, I'll post the results.

    Thanks, Sean A. McKenna

  smckenna@slate.mines.colorado.edu

Name of School? ______________________________
Name of Dept.?  ______________________________
Semester or Quarter System? __________________
Degrees offered by Dept. (MS/PhD and Geology,
   Geophysics, Geochemistry, Geological 
   Engineering, etc.)?  _______/______________
   ___________________________________________
   ___________________________________________
How many credit hours does your program require
   for an MS ?  __________
How many for a PhD (from a BS/BA) ? __________
How many for a PhD (from an MS) ? __________
Are there fewer hours required for a PhD if an MS
   was earned at the same institution versus an MS
   from another school (Y/N) ? ____________
Does your department have required courses for every
   student (ie., core courses) (Y/N) _________
If yes, how many credits/courses do they total ?
   _________/__________
What are the titles?  ______________________________
   _________________________________________________
   _________________________________________________
Is a minor required outside the department (Y/N)?
   _________
If yes, how many hours/courses are necessary?
   _____________/____________
Does your department have distribution requirements
   (ie, a grad level stratigraphy, geochem and 
   structural course for everyone) (Y/N) ? ________
What are the titles? ______________________________
  _________________________________________________
  _________________________________________________
Make a guess at the "average" time it takes to get an
  MS in your program ______________________________
  A PhD from already having an MS _________________
  A PhD from a BS/BA ______________________________
From: snorthc@relay.nswc.navy.mil (Stephen Northcutt - K31)
Newsgroups: sci.geo.geology
Subject: Earthquakes
Keywords: Major quakes increasing?
Date: 4 Jan 93 20:18:01 GMT
Reply-To: snorthc@relay.nswc.navy.mil
Organization: Naval Surface Warfare Center

My kid has his first school research assignment: earthquakes.  So I went
with him over xmas break to the public library.  I guess the other 4th
graders mostly beat us since most of the books were checked out.

I went by the research section, and looked at an almanac (disasters and
major quakes)  if the almanac is correct, most (by a humungeous majority)
major quakes have occured this century.  Is this possible?  Or is this a
function of better data recording?

I understand that in terms geologic time scale there would have been times of
more and less than this century, but what about a 1 - 2000 year span?

Thanks!
From: theodore@unity.ncsu.edu (Andrew M Smith)
Newsgroups: sci.geo.geology
Subject: The Geology of the Dead Sea Rift (Arava Valley)
Date: 7 Jan 93 05:20:04 GMT
Organization: NCSU
Originator: theodore@post.cc.ncsu.edu

I would like more information concerning the Arava valley that borders
both Israel and Jordan.  The Arava is that part of the Dead Sea Rift that
extends from the Dead Sea to the Red Sea.  Can anyone discuss current
research in this region and possibly give sources for more information?

Any responses will be appreciated.
-- 
________________________________________________________________________
A M S II			          Email: theodore@unity.ncsu.edu
Newsgroups: sci.geo.geology
From: jh507@ripplegeosc.psu.edu (John Hammer for GEOSC 507)
Subject: Earthquake distribution
Keywords: San Andreas, California
Organization: Penn State University, College of Earth & Mineral Sciences
Date: Tue, 5 Jan 1993 20:04:05 GMT

Does anyone know of a good data base of Central Califorinia earthquakes
along the San Andreas?  I'm looking for a source with reasonably accurate
depths.  I am interested in the area to the east of Monterey Bay.
Could someone point me to a source or ftp site?

Thank you very much, 
  Reply here or by e-mail,
John

John Hammer
e-mail: hammer@geosci.psu.edu
Penn State Geosciences

Newsgroups: sci.geo.geology
From: okunewck@psuvax1.cs.psu.edu (Phil OKunewick)
Subject: Re: where to get rock hammer?
Organization: Random, at best
Distribution: na
Date: Tue, 5 Jan 1993 18:46:49 GMT

rob@xyzoom.info.com (Rob Lingelbach) writes:
>2) are there any group-type field trips for amateurs like me, led by a
>geologist? 

   You could try signing up for a college course that involves field
work.  I've heard of geology clubs, but I don't know of any offhand.
Contact your local museum.

>3) is it OK these days to remove, from BLM land mostly I guess,
>specimens?  The books I have do cover the possibility of mining claims
>and what to do about them.

It's up to the property owner.  I've found a lot of nice specimens in
abandoned quarries, and nobody has ever objected to me removing them :-).

National Parks are illegal for collecting, but there's nothing wrong with
admiring a rock and putting it back.

I don't know about BLM lands.

>4) when I use my rock hammer, are my glasses, which have safety glass,
>considered protective eyewear?

   Nope.  Chips can sneak around the glasses and hit you in the eye.
You need safety glasses that completely surround your eyes.  My eye
glasses have stopped many airborne objects from entering my eyes, but
not all.  I have some small scars on my eyeballs.

   Another consideration - the steel in a hammer head is built for
durability, and is designed to maintain its shape while it deforms the
struck object.  The head isn't very malleable; if the energy isn't
expended on the object, the hammer head will shatter.  Striking two
hammers together (e.g. using one rock hammer for a chisel) is a very
very bad thing to do.  I've seen the results; not pretty.

   You want to use a chisel with your rock hammer for extracting
specimens, not the pick end.  This will give you a much more accurate
blow, and will protect the tools from shattering.  The hammered end of
the chisel is softer steel than the hammer, so it absorbs the blow
that would otherwise shatter things.


>5) is this the best place for me to be asking these questions?  ;-)

It's the best newsgroup, that's for sure.

Newsgroups: sci.geo.geology
From: guy@slustl.slu.edu (Guy Smith)
Subject: Re: Basic Geology Books...
Organization: Saint Louis University  Saint Louis, MO
Date: Thu, 7 Jan 1993 18:41:01 GMT

In article <1993Jan7.153508.2742@msdhsv.ingr.com> rock@medch.b17b.ingr.com writes:
>What are some good basic geology books or texts?  I know little about geology, 
>but because of my interest in caving, I'm interested in learning more about it.
>
This is something of a theological issue but I'll give you my prejudices.
Basic physical geology, Tarbuck and Lutgens "The Earth"
A little more advanced, Press and Siever, "Earth"
These are both freshman level texts. There are many others but I've
taught from these and like them.
From: xm9@sdcc12.ucsd.edu (richard g. adair)
Newsgroups: sci.geo.geology
Subject: Re: Question about Earth's magnetic poles
Date: 9 Jan 93 17:29:16 GMT
Organization: University of California, San Diego

>...  I read somewhere a speculation that there may be a period of a
>1000 years when there are no poles during one of these reversals.  Must make
>the Homing Pigeons nuts!   BTW Plummer and McGeary say we are 200,000 years
>overdue for a reversal.

I've heard that bird navigation by geomagnetic means may not be as
important as once thought [comments? data?].  I would tend to believe 
this, since birds, which have been around for millions of years, 
must have lived through several reversals.  Having non-magnetic 
navigational ability sounds like part of a basic survival kit.
Xref: sparky sci.geo.geology:2688 ca.earthquakes:1532