PLEASE NOTE:
*
Date sent: Fri, 27 Jun 1997 15:12:35 -0400 (EDT)
From: Benny J Peiser <B.J.PEISER@livjm.ac.uk>
Subject: Re: EARTH CRATERING RECORD
To: cambridge-conference@livjm.ac.uk
Priority: NORMAL
EARTH CRATERING RECORD AND IMPACT ENERGY FLUX IN THE LAST 150 Ma
From: Prof Paolo Farinella (University of Pisa)
<paolof@keplero.dm.unipi.it>
Here is the abstract of a paper of which I am a coauthor, and
which may
be interesting for list members. Preprints are available upon
request
(my coordinates are at the end of this e-mail).
=======================================================================
EARTH CRATERING RECORD AND IMPACT ENERGY FLUX IN THE LAST 150 Ma
A. Montanari, A. Campo Bagatin and P. Farinella
ABSTRACT. Although the Earth's cratering record is subject to
strong
bias (i.e.., unknown craters yet to be discovered or obliterated
by
geological processes, geochronologic uncertainties of impact
events), a
compilation of 33 best dated large impact craters on Earth with
diameters >5 km and younger than 150 Ma, their diameters,
geochronologic ages, and the corresponding uncertainties can be
used to
contruct a diagram summarizing our current knowledge on the
influx of
impact energy onto the Earth versus time. From the crater
diameters, we
estimated the corresponding impact energies through suitable
scaling
laws. Then, we associated to each crater a gaussian (bell)
function of
time centered at its age, with a half-width consistent with the
age
uncertainty and a total area proportional to the impact energy.
Finally, all the bell functions corresponding to different
craters were
summed up and the resulting curve (smoothed out by computing
running
averages over 4 Ma) was plotted in a semilogarithmic scale. From
this
curve, it is apparent that the recently discovered 144.7 Ma old
Morokweng crater in South Africa, whih is associated with the
Jurassic/Cretaceous boundary and related mass extinction,
corresponds
to the highest energy influx peak, almost an order of magnitude
larger
than the Chicxulub crater in Yucatan which, on the other hand, is
associated with the Cretaceous/Tertiary mass extinction, the most
severe in the marine record of the last 150 Ma. The third largest
impact energy flux peak corresponds to the Late Eocene Popigai
(Siberia) and Cheasapeake Bay (USA) giant impact craters, which
are
also associated with a global biotic crisis. From the overall
record
examined herein it emerges that there is probably a threshold
size of
approximately 3 km for the smallest projectile capable of
triggering
large-scale extinctions. There is no convincing evidence of
periodicities in the distribution of crater ages. However, a few
groups
of several craters (e.g., in the Late Eocene) appear to be more
closely
spaced in time than in a purely random distribution.
>
=======================================================================
> Paolo Farinella Tel. +39-50-844254 <=== NEW!
> Dipartimento di Matematica Fax +39-50-844224 <=== NEW!
> Universita` di Pisa
> Via F. Buonarroti 2 e-mail paolof@dm.unipi.it
> I-56127 Pisa, Italy WWW: http://adams.dm.unipi.it/~paolof
>
=======================================================================
*
From: Leroy Ellenberger <cle@imr-stl.com>
To: Leroy Ellenberger <cle@imr-stl.com>,
Benny J Peiser <B.J.PEISER@livjm.ac.uk>,
cambridge-conference <cambridge-conference@livjm.ac.uk>
Copies to: df736 <df736@freenet.carleton.ca>, hhbauer
<hhbauer@vt.edu>
Subject: Re: GLOBAL EFFECTS OF THE THERA ERUPTION
Date sent: Fri, 27 Jun 1997 09:55:24 -0500
Pardon this esprit d'escalair, but I feel the need to make some
supplementary remarks for clarity's sake without getting into
a lot of unnecessary (for this forum) detail. One: every known,
major eruption in the past 2000 years has produced a sulfuric
acid signal above background AT THE CORRECT PLACE in the
ice, including Krakatoa in 1883, Tambora in 1815 and Kuwae in
1453. The only thing that makes the Minoan eruption of Thera
problemmatical is the fact that we have no independent
historical date for it. So it has been associated with the only
major sulfuric acid signal in the ice in the relevant date range.
As I noted in an earlier post, quoting my letter in Jl/Ag 1991
THE SCIENCES, the other two candidate acidity signals in the
ice were nitric, which is not diagnostic for volcanism, but which
can have a cosmic origin in the context of Clube & Napier's
Taurid complex model. And at the risk of being too self-serving,
it is not impossible that the eruption of Thera occurred in close
proximity to a major episode of Taurid stream activity. But this
would require some major field work and analytical programs,
which are beyond my means, to ascertain.
Cheers, Leroy
----------
> From: Leroy Ellenberger <cle@imr-stl.com>
> To: Benny J Peiser <B.J.PEISER@livjm.ac.uk>;
cambridge-conference
<cambridge-conference@livjm.ac.uk>
> Cc: df736 <df736@freenet.carleton.ca>; hhbauer
<hhbauer@vt.edu>
> Subject: Re: GLOBAL EFFECTS OF THE THERA ERUPTION
> Date: Friday, June 27, 1997 9:31 AM
>
> Regarding Gunnar Heinsohn's concerns expressed in his
message
> below, the acidity signal in the Greenland ice cores
identified with
> the Minoan eruption of Thera is a correlation. However, this
being
> said by no means undermines the annual nature of the ice
cores
> stratigraphy, whose annual nature has been demonstrated over
> and over again in the professional glaciology literature and
which
> status is beyond dispute. The relevant papers have been
cited in
> secondary literature that is available to Heinsohn, being,
namely,
> the articles/papers on ice core research/results in KRONOS
X:1,
> 1984, by the writer, and Sean Mewhinney's devastating
response
> to Lynn Rose on ice core methodology in CATASTROPHISM &
> ANCIENT HISTORY XII:1 and XII:2, 1990. Every major, known
> eruption in the common era is represented by an acidity
signal
> in the ice cores and all of the MANY independent annual
signals
> in the ice maintain a constant phase relation to each other.
These
> signals include background acidity, micro-particle
concentration,
> various ionic species, oxygen isotope ratios, and others.
After
> all the discussion of ice core methodology since 1984 in the
amateur
> catastrophist literature, I am appalled that the sort of
nihilism
> represented by Heinsohn's instant message. The glaciology
literature
> is in the public domain for anyone to read for meaning. It
is high
> time for amateur, renegade, radical chronology revisers, of
which
> Heinsohn is only one representative, "to read the
original sources
> for themselves at first-hand", as their exemplar
exhorted them to do
> before he died in November 1979.
> I apologize if my rhetoric above offends any reader; but
this
nihilistic,
> guerrilla movement to discredit every methodology that
contradicts
> one's sacred cow has gone on far too long with respect to
the ice core
> record (whose results with every new core from Greenland,
Antarctica,
> China, Chili, etc. only serves to confirm the original
insights/results
> that have been known since at least 1978 (and which were
anticipated
> in the mid-1960s)) for such "truth seeking"
gambits as Heinsohn's
> instant posting to be given any serious consideration.
> I would hate to learn that the potential of the Cambridge
Conference
> in July was compromised by tactics presaged by the hidden
agenda
> implicit in Heinsohn's posting.
>
> Sincerely,
> Leroy Ellenberger
>
> --C. Leroy Ellenberger, "vivere est vincere"
> http://abob.libs.uga.edu/bobk/velidelu.html
> ftp://ftp.primenet.com/pub/lippard/; 9 cle-files
> cle@imr-stl.com
> ----------
> > From: Benny J Peiser <B.J.PEISER@livjm.ac.uk>
> > To: cambridge-conference@livjm.ac.uk
> > Subject: Re: GLOBAL EFFECTS OF THE THERA ERUPTION
> > Date: Friday, June 27, 1997 7:50 AM
> >
> > GLOBAL EFFECTS OF THE THERA ERUPTION
> >
> > Prof Gunnar Heinsohn of the University of Bremen
(Germany) has asked
> > for more detailed information about the fundamental
principles and
> > limitations of ice core research and the methods of
linking significant
> > acidity layers in Greenland ice cores with historical
volcanic
> > eruptions. Please do not hesitate to contact Prof
Heinsohn directly,
> > should members of this list wish to discuss these
issues.
> >
> > Benny J Peiser
> >
----------------------------------------------------------------------
> >
> > From: Gunnar Heinsohn <gheins@uni-bremen.de>
> >
> > ARE VOLCANIC DISASTERS OVERRATED?
> >
> > (i) If I am properly informed volcano acidity is not
> > fingerprinted. There is thus no positiv proof for Thera
in the ice
> > cores but only a chronological correlation.
> >
> > (ii) So far it does not seem to be clear if the
so-called
> > annual layers in the icecores are individual compacted
snowfalls or
> > individual years. If they represent individual years I
would like to
> > know how the individually sedimented snowfalls are
accounted for in an
> > "annual layer."
> >
> > Gunnar Heinsohn
> >
*
From: Leroy Ellenberger <cle@imr-stl.com>
To: Benny J Peiser <B.J.PEISER@livjm.ac.uk>,
cambridge-conference <cambridge-conference@livjm.ac.uk>
Copies to: df736 <df736@freenet.carleton.ca>, hhbauer
<hhbauer@vt.edu>
Subject: Re: GLOBAL EFFECTS OF THE THERA ERUPTION
Date sent: Fri, 27 Jun 1997 09:31:51 -0500
Regarding Gunnar Heinsohn's concerns expressed in his message
below, the acidity signal in the Greenland ice cores identified
with
the Minoan eruption of Thera is a correlation. However, this
being
said by no means undermines the annual nature of the ice cores
stratigraphy, whose annual nature has been demonstrated over
and over again in the professional glaciology literature and
which
status is beyond dispute. The relevant papers have been cited in
secondary literature that is available to Heinsohn, being,
namely,
the articles/papers on ice core research/results in KRONOS X:1,
1984, by the writer, and Sean Mewhinney's devastating response
to Lynn Rose on ice core methodology in CATASTROPHISM &
ANCIENT HISTORY XII:1 and XII:2, 1990. Every major, known
eruption in the common era is represented by an acidity signal
in the ice cores and all of the MANY independent annual signals
in the ice maintain a constant phase relation to each other.
These
signals include background acidity, micro-particle concentration,
various ionic species, oxygen isotope ratios, and others. After
all the discussion of ice core methodology since 1984 in the
amateur
catastrophist literature, I am appalled that the sort of nihilism
represented by Heinsohn's instant message. The glaciology
literature
is in the public domain for anyone to read for meaning. It is
high
time for amateur, renegade, radical chronology revisers, of which
Heinsohn is only one representative, "to read the original
sources
for themselves at first-hand", as their exemplar exhorted
them to do
before he died in November 1979.
I apologize if my rhetoric above offends any reader; but this
nihilistic,
guerrilla movement to discredit every methodology that
contradicts
one's sacred cow has gone on far too long with respect to the ice
core
record (whose results with every new core from Greenland,
Antarctica,
China, Chili, etc. only serves to confirm the original
insights/results
that have been known since at least 1978 (and which were
anticipated
in the mid-1960s)) for such "truth seeking" gambits as
Heinsohn's
instant posting to be given any serious consideration.
I would hate to learn that the potential of the Cambridge
Conference
in July was compromised by tactics presaged by the hidden agenda
implicit in Heinsohn's posting.
Sincerely,
Leroy Ellenberger
--C. Leroy Ellenberger, "vivere est vincere"
http://abob.libs.uga.edu/bobk/velidelu.html
ftp://ftp.primenet.com/pub/lippard/; 9 cle-files
cle@imr-stl.com
----------
> From: Benny J Peiser <B.J.PEISER@livjm.ac.uk>
> To: cambridge-conference@livjm.ac.uk
> Subject: Re: GLOBAL EFFECTS OF THE THERA ERUPTION
> Date: Friday, June 27, 1997 7:50 AM
>
> GLOBAL EFFECTS OF THE THERA ERUPTION
>
> Prof Gunnar Heinsohn of the University of Bremen (Germany)
has asked
> for more detailed information about the fundamental
principles and
> limitations of ice core research and the methods of linking
significant
> acidity layers in Greenland ice cores with historical
volcanic
> eruptions. Please do not hesitate to contact Prof Heinsohn
directly,
> should members of this list wish to discuss these issues.
>
> Benny J Peiser
>
----------------------------------------------------------------------
>
> From: Gunnar Heinsohn <gheins@uni-bremen.de>
>
> ARE VOLCANIC DISASTERS OVERRATED?
>
> (i) If I am properly informed volcano acidity is not
> fingerprinted. There is thus no positiv proof for Thera in
the ice
> cores but only a chronological correlation.
>
> (ii) So far it does not seem to be clear if the so-called
> annual layers in the icecores are individual compacted
snowfalls or
> individual years. If they represent individual years I would
like to
> know how the individually sedimented snowfalls are accounted
for in an
> "annual layer."
>
> Gunnar Heinsohn
>
*
Date sent: Fri, 27 Jun 1997 09:15:40 -0400 (EDT)
From: Benny J Peiser <B.J.PEISER@livjm.ac.uk>
Subject: THE CHESAPEAKE BAY IMPACT
To: cambridge-conference@livjm.ac.uk
Priority: NORMAL
THE CHESAPEAKE BAY IMPACT
C W Poag: The Chesapeake Bay bolide impact: A convulsive event in
Atlantic Coastal Plain evolution. In: SEDIMENTARY GEOLOGY, 1997,
Vol.108, No.1-4, p.45
Until recently, Cenozoic evolution of the Atlantic Coastal Plain
has
been viewed as a subcyclical continuum of deposition and erosion.
Marine transgressions alternated with regressions on a slowly
subsiding
passive continental margin, their orderly succession modified
mainly
by isostatic adjustments, occasional Appalachian tectonism, and
paleoclimatic change. This
passive scenario was dramatically transformed in the late Eocene,
however, by a bolide
impact on the inner continental shelf. The resultant crater is
now buried 400-500 m beneath
lower Chesapeake Bay, its surrounding peninsulas, and the
continental shelf east of Delmarva
Peninsula. This convulsive event, and the giant tsunami it
engendered, fundamentally changed
the regional geological framework and depositional regime of the
Virginia Coastal Plain, and
produced the following principal consequences. (1) The impact
excavated a roughly circular
crater, twice the size of Rhode Island (similar to 6400 km(2))
and nearly as deep as the
Grand Canyon (similar to 1.3 km deep). (2) The excavation
truncated all existing
ground-water aquifers in the target area by gouging similar to
4300 km(3) of rock from the
upper lithosphere, including Proterozoic and Paleozoic
crystalline basement rocks and Middle
Jurassic to upper Eocene sedimentary rocks. (3) Synimpact
depositional processes, including
ejecta fallback, massive crater-wall failure, water-column
collapse, and tsunami backwash,
filled the crater with a porous breccia lens, 600-1200 m thick,
at a phenomenal rate of
similar to 1200 m/hr. The breccia lens replaced the truncated
ground-water aquifers with a
single 4300 km(3) reservoir, characterized by ground water
similar to 1.5 times saltier than
normal sea water (chlorinities as high as 25,700 mg/l). (4) A
structural and topographic
low, created by differential subsidence of the compacting
breccia, persisted over the crater
at least through the Pleistocene. In the depression are preserved
postimpact marine
lithofacies and biofacies (upper Eocene, lower Oligocene, lower
Miocene) not known elsewhere
in the Virginia Coastal Plain. (5) Long-term differential
compaction and subsidence of the
breccia lens spawned extensive fault systems in the postimpact
strata. Many of these faults
appear to reach the bay floor, and may be potential hazards for
motion-sensitive structures
in population centers around Chesapeake Bay. Near-surface
fracturing and faulting generated
by the impact shock may extend as far as 90 km from the crater
rim. (6) Having never
completely filled with postimpact sediments, the sea-floor
depression over the crater
appears to have predetermined the location of Chesapeake Bay. (7)
As large impact craters
are principal sources for some of the world's precious metals, it
is reasonable to expect
that metal-enriched sills, dikes, and melt sheets are present in
the inner basin of the
crater. In addition to these specific consequences, the crater
and the convulsive event that
produced it, have widespread implications for traditional
interpretations of certain
structural and depositional features of the Atlantic Coastal
Plain, particularly in
southeastern Virginia.
*
Date sent: Fri, 27 Jun 1997 08:59:23 -0400 (EDT)
From: Benny J Peiser <B.J.PEISER@livjm.ac.uk>
Subject: Mars Pathfinder Update - 06/26/97
To: cambridge-conference@livjm.ac.uk
Priority: NORMAL
From: Ron Baalke <BAALKE@kelvin.jpl.nasa.gov>
PUBLIC INFORMATION OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011
http://www.jpl.nasa.gov
Mars Pathfinder Mission Status
June 26, 1997
Mars Pathfinder, now eight days away from landing on the
surface of Mars, performed the last of its scheduled trajectory
correction maneuvers at 10 a.m. Pacific Daylight Time on
Wednesday, June 25.
The correction maneuver was performed in two phases
occurring 45 minutes apart. The first burn, lasting just 1.6
seconds, involved firing four thruster engines on one side of the
vehicle. The second burn lasted 2.2 seconds and involved firing
two thrusters closest to the heat shield. The combined effect of
both burns changed Pathfinder's velocity by 0.018 meters per
second (0.04 miles per hour), which places the spacecraft on
target for a July 4 landing in an ancient flood basin called Ares
Vallis. Pathfinder is scheduled to land at 10:07 a.m. PDT (in
Earth-received time). The one-way light time from Mars to Earth
is 10 minutes, 35 seconds, so in actuality, Pathfinder lands at
9:57 a.m. PDT.
If necessary, a fifth trajectory correction maneuver may be
performed just before Pathfinder hits the upper atmosphere of
Mars. The maneuver would be carried out either 12 hours or six
hours before Pathfinder reaches the atmosphere at 10 a.m. PDT in
Earth-received time. The flight team will make a decision to
proceed with the final correction maneuver the evening before
landing.
A final health check of the spacecraft and rover was
performed on June 20. All spacecraft systems, including science
instruments and the critical radar altimeter, remain in excellent
health from the last check about six months ago. The rover
received a "wake up" call, woke up on command from the
lander,
then accepted a software upgrade. Flight controllers next loaded
the 370 command sequences that will be required by Pathfinder to
carry out its surface operations mission.
The spacecraft is now ready to begin its entry, descent and
landing phase. It will be commanded into that mode at 1:42 p.m.
PDT on June 30 by an onboard sequence.
Mars Pathfinder is currently about 180 million kilometers
(111 million miles) from Earth and about 3.5 million kilometers
(2.2 million miles) from Mars. After 202 days in flight, the
spacecraft is traveling at about 18,000 kilometers per hour
(12,000 miles per hour) with respect to Mars.
#####
*
Date sent: Fri, 27 Jun 1997 08:57:45 -0400 (EDT)
From: Benny J Peiser <B.J.PEISER@livjm.ac.uk>
Subject: Public will Have Internet View of Mars Pathfinder
Activities
To: cambridge-conference@livjm.ac.uk
Priority: NORMAL
From: Ron Baalke <BAALKE@kelvin.jpl.nasa.gov>
PUBLIC INFORMATION OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011
http://www.jpl.nasa.gov
Contact: Diane Ainsworth
FOR IMMEDIATE RELEASE June 24, 1997
PUBLIC WILL HAVE INTERNET VIEW OF PATHFINDER ACTIVITIES
Internet users around the world may begin following the Mars
Pathfinder spacecraft as it approaches Mars and prepares for a
July 4 landing by way of a variety local mirror sites that are
now online.
The Internet sites feature updates on mission activities,
and will provide Pathfinder photographs of the Martian surface
once they become available. The sites also feature a bird's eye
view of the Mars Pathfinder mission operations area at NASA's Jet
Propulsion Laboratory, Pasadena, CA, via a live video camera feed
that is updated every 15 minutes.
"We're expecting a siege of hits on July 4," said David
Dubov, Mars Pathfinder webmaster at JPL. "Our best estimate,
based on past events such as Galileo, the Comet Shoemaker-Levy 9
collision in 1994, Comet Hale-Bopp's return and other celestial
events has led us to plan for at least 25 million hits on July 4,
and a similar level of hits per day during the week following
landing."
To accommodate the overwhelming interest among the public,
JPL will have about 20 mirror sites around the world by the end
of June so that people can use the sites closest to their homes
rather than trying to access the JPL site. "Most of the
domestic
sites were picked because of their connection to the National
Science Foundation backbone, a very robust network that can
handle high traffic," said Kirk Goodall, Mars Pathfinder web
engineer. "Combined, these mirror sites will be able to
service
up to 30 million hits per day."
During landing day activities and the Pathfinder rover's
primary, seven-day mission, members of the public should access
the following Pathfinder mirror sites closest to their homes:
CORPORATE MIRROR SITES
Silicon Graphics Computer Systems, Inc.
http://mars.sgi.com
Load capacity per day: 15 million hits/day
CompuServe, Inc.
http://mars.compuserve.com
Load capacity per day: 10 million hits/day
Sun Microsystems, Inc.
http://www.sun.com/mars
Load capacity per day: 6 million hits/day
PUBLIC SECTOR MIRROR SITES
NASA Ames Research Center
Moffet Field, CA
http://mpfwww.arc.nasa.gov
Load capacity per day: 5 million hits/day
National Center for Supercomputer Applications (NCSA)
University of Illinois at Urbana-Champagne, IL
http://www.ncsa.uiuc.edu/mars
Load capacity per day: 4 million hits/day
Cornell Theory Center
Cornell University, NY
http://mars.tc.cornell.edu
Load capacity per day: 4 million hits/day
National Center for Atmospheric Research (NCAR #1)
Boulder, CO
http://www.mars.ucar.edu
Load capacity per day: 4 million hits/day
San Diego Supercomputer Center
San Diego State University, CA
http://mars.sdsc.edu
Load capacity per day: 4 million hits/day
NASA Kennedy Space Center
Cape Canaveral, FL
http://www.ksc.nasa.gov/mars
Load capacity per day: 2 million hits/day
Jet Propulsion Laboratory
Pasadena, CA
http://www.jpl.nasa.gov/mpfmir
Load capacity per day: 1 million hits/day
National Center for Atmospheric Research
(NCAR #2) Boulder, CO
http://mars.nlanr.net
Load capacity per day: 1 million hits/day
Pittsburgh Supercomputing Center
University of Pittsburgh, PA
http://www.psc.edu/Mars
Load capacity per day: 750,000 hits/day
NASA Lewis Research Center
Dayton, OH
http://pathfinder.lerc.nasa.gov
Load capacity per day: 500,000 hits/day
The Catlin Gabel School
Portland, OR
http://mars.catlin.edu
Load capacity per day: 500,000 hits/day
INTERNATIONAL MIRROR SITES
National Space Development Agency of Japan (NASDA)
Tokyo, Japan
http://mars.tksc.nasda.go.jp/JPL
Load capacity per day: 2 million hits/day
Centre National d'Etudes Spatiales (CNES)
France http://www-mars.cnes.fr
Load capacity per day: 1 million hits/day
The Australian Commonwealth Scientific and Industrial Research
Organization (CSIRO)
Sydney, Australia
http://sparkli.tip.csiro.au/mars
Load capacity per day: 1 million hits/day
Canberra Deep Space Communication Complex CDSCC - NASA/JPL)
Canberra, Australia
http://tid.cdscc.nasa.gov/mars
Load capacity per day: 500,000 hits/day
IKI (Institute for Space Science)
Moscow, Russia
http://www.iki.rssi.ru/jplmirror/mars
Load capacity per day: 250,000 hits/day
Mars Pathfinder is the second in NASA's Discovery program of
low-cost spacecraft with highly focused science goals. The Jet
Propulsion Laboratory, Pasadena, CA, manages the Mars Pathfinder
mission for NASA's Office of Space Science, Washington, D.C.
#####
*
Date sent: Fri, 27 Jun 1997 08:50:06 -0400 (EDT)
From: Benny J Peiser <B.J.PEISER@livjm.ac.uk>
Subject: Re: GLOBAL EFFECTS OF THE THERA ERUPTION
To: cambridge-conference@livjm.ac.uk
Priority: NORMAL
GLOBAL EFFECTS OF THE THERA ERUPTION
Prof Gunnar Heinsohn of the University of Bremen (Germany) has
asked
for more detailed information about the fundamental principles
and
limitations of ice core research and the methods of linking
significant
acidity layers in Greenland ice cores with historical volcanic
eruptions. Please do not hesitate to contact Prof Heinsohn
directly,
should members of this list wish to discuss these issues.
Benny J Peiser
----------------------------------------------------------------------
From: Gunnar Heinsohn <gheins@uni-bremen.de>
ARE VOLCANIC DISASTERS OVERRATED?
(i) If I am properly informed volcano acidity is not
fingerprinted. There is thus no positiv proof for Thera in the
ice
cores but only a chronological correlation.
(ii) So far it does not seem to be clear if the so-called
annual layers in the icecores are individual compacted snowfalls
or
individual years. If they represent individual years I would like
to
know how the individually sedimented snowfalls are accounted for
in an
"annual layer."
Gunnar Heinsohn