PLEASE NOTE:


*

CCNet 110/2000 - 30 October 2000
--------------------------------


      "As from 1 November countries where a natural or technological
disaster has occurred will  be able to enlist emergency support from the
space facilities of the European Space Agency (ESA), the Centre National
d'Etudes Spatiales (CNES, France) and the Canadian Space Agency
(CSA) by simply calling a confidential telephone number."
           -- European Space Agency, 27 October 2000


(1) ASTEROID PORTFOLIO GETS A BOOST WITH NEW OPTICS
    SpaceDaily, 26 October 2000

(2) SEARCH AND DESTROY
    Frankfurter Allgemeine Zeitung, 26 October 2000

(3) ECHOES OF ATLANTIS
    The Guardian, 25 October 2000

(4) INTERNATIONAL SPACE FACILITIES TO ASSIST DISASTER MANAGEMENT
    European Space Agency <esaweb@esrin.esa.it>

(5) WHEN IS A PLANET NOT A PLANET?
    Andrew Yee <ayee@nova.astro.utoronto.ca>

(6) LATE EOCENE IMPACT EJECTA
    James Whitehead <jwhitehe@unb.ca>

(7) ASTEROID ARTICLE IN GERMAN NEWSPAPER (FAZ)
    Phil Plait <badastro@badastronomy.com>

(8) NEW SCIENTIST FAILS TO CORRECT SENSATIONALIST SCARE STORY
    Michael Paine <mpaine@tpgi.com.au>

(9) AND FINALLY: LEAKED DRAFT DOCUMENT CLAIMS GLOBAL WARMING 'WORSE THAN FEARED'
    BBC Online News, 30 October 2000

=================
(1) ASTEROID PORTFOLIO GETS A BOOST WITH NEW OPTICS

From SpaceDaily, 26 October 2000
http://www.spacedaily.com/news/asteroid-00r.html

Boulder - Oct. 26, 2000

Large telescopes with deformable optics are allowing astronomers to study
distant asteroids with unprecedented clarity -- leading to the discovery of
new shapes and configurations and presenting scientists with new puzzles to
solve.

An international team of astronomers led by Dr. William Merline of the
Boulder office of Southwest Research Institute (SwRI) released today the
first-ever images of a large, double asteroid. Each asteroid in the pair is
the size of a large city (about 50 miles across), separated by about 100
miles, mutually orbiting the vacant point of interplanetary space that lies
midway between them. The discovery was made using the W.M. Keck Observatory
atop Mauna Kea, the tallest mountain in Hawaii. The asteroid pair was once
assumed to be a single body, called Antiope, orbiting the sun in the outer
parts of the asteroid belt between the orbits of Mars and Jupiter.

The team also released a picture of a small moon orbiting the large asteroid
Pulcova. This moon was discovered in February 2000 using the
Canada-France-Hawaii Telescope (CFHT), also on Mauna Kea. It is only the
third asteroid discovered to have a small moon. Asteroid-moon pairs had not
been seen until 1993, when the Galileo spacecraft imaged the one-mile-wide
moonlet Dactyl, as it rushed past the 19-mile-diameter asteroid Ida. The
Merline team reported the second asteroidal moonlet a year ago, circling the
135-mile-sized asteroid Eugenia. The team named the companion Petit-Prince,
officially accepted by the International Astronomical Union in August.

"It's getting to be kind of bewildering," says Dr. Christophe Dumas of the
Jet Propulsion Laboratory (JPL), a team astronomer. "Asteroids were once
thought to be single, mountain-like chunks of material, perhaps smashed into
'flying rubble piles' by occasional collisions among themselves."

Astronomers expect strange new configurations to provide still more
surprises as the survey continues. "Every new asteroidal companion we
discover seems to bring new configurations and new mysteries," says team
member Dr. Clark R. Chapman, also of the SwRI Boulder office.

The team's approach uses a new technology, called adaptive optics, which
enables telescopes to see asteroids and other small points of light in the
heavens with the same clarity as the Hubble Space Telescope. Until recently,
ground-based telescopes were hindered by distortions caused by Earth's
atmosphere, in much the same way water distorts the view of an underwater
object. The new technique passes light from the telescope through a
specialized "correction box" to instantaneously analyze the distorted light
and compute the amount of correction necessary to remove the blurring of the
atmosphere. The correction information is then fed to deformable mirrors in
the box that remove the distortion, providing a sharper image. CAPTION: 216
Kleopatra Rotation Movie This is a movie of the rotation of asteroid 216
Kleopatra in Nov 1999, when radar data were also beign acquired, that showed
the weird 'dog-bone' shape of this asteroid. These data are from CFHT. The
asteroid rotates once every about 5 hours.

A fascinating demonstration of the new telescope technology is in a movie of
the asteroid Kleopatra, also released today, observed during a seven-hour
period. Earlier this year, Steve Ostro of JPL published reconstructions of
Kleopatra's shape based on radar reflections obtained when that asteroid was
fairly close to the Earth in November 1999. During the same month, team
member Dr. Francois Menard, currently a visiting scientist at CFHT, obtained
adaptive optics images. "Excellent agreement of both optical and radar
pictures of Kleopatra's 'dog-bone' shape provides added confidence in the
reliability of adaptive optics images," says Menard.

"Radar works well for asteroids near the Earth, but adaptive optics is much
more powerful for studying asteroids in the middle of the asteroid belt and
beyond," says Dr. Laird Close of the European Southern Observatory and the
University of Arizona.

This week, Merline and his colleagues reported to an annual meeting of
international scientists specializing in solar system studies on two years
of asteroid surveys conducted at three observatories equipped with the new
adaptive optics systems.

"In fact, large asteroidal satellites and twin companions are rather rare,"
Merline told attendees of the 32nd annual meeting of the American
Astronomical Society's Division for Planetary Sciences, convened this week
in Pasadena, California. "Preliminary study of about 200 asteroids has
turned up only two asteroids with moons (Eugenia and Pulcova) and just one
double (Antiope)," he explains. "It is possible that a few more moonlets
might emerge from more sophisticated analysis of the data we have
collected."

Pulcova is an asteroid about 90 miles in diameter. Its small satellite,
roughly a 10th its size, orbits Pulcova every four days at a distance of
about 500 miles.

Asteroidal companions provide vital information about asteroids that has
been difficult to obtain. Until now, the best measurements of asteroid
masses -- their bulk densities, such as whether they are "light" like ice,
"dense" like metal, or in between like rocks -- came from deflections of
spacecraft flying past an asteroid. Such spacecraft encounters are rare, and
deflections of more distant objects (other asteroids or planets) by an
asteroid's gravity are weak and difficult to measure. But an asteroidal
satellite, or twin, is a body whose trajectory is so mightily deflected by
the asteroid's gravity that it is actually forced to orbit around it. The
revolution time provides a measure of the body's mass, hence density. Using
such techniques, Merline's team find that Eugenia, Pulcova, and Antiope are
all rather light bodies. They are much less dense than familiar rocks, more
like ice, but their surfaces appear very dark, like rock. Interesting
differences in the densities motivate further research on asteroids with
satellites.

NASA and the National Science Foundation are funding this research.
Observations are being conducted at the Keck Observatory and the CFHT
(operated by the National Research Council of Canada, the French Centre
National de la Recherche Scientifique, and the University of Hawaii). Other
team members are Dr. J. Chris Shelton (Mt. Wilson Observatory) and Dr. David
Slater (SwRI, San Antonio).

SwRI is an independent, nonprofit, applied research and development
organization based in San Antonio, Texas, with more than 2,700 employees and
an annual research volume of more than $300 million.

Copyright 2000, SpaceDaily

================
(2) SEARCH AND DESTROY

From Frankfurter Allgemeine Zeitung, 26 October 2000
http://www.faz.com/IN/INtemplates/eFAZ/docmain.asp?rub={F1B72E2C-3783-11D4-A3AA-009027BA22E4}&doc={1104D9E7-AA5C-11D4-A3B2-009027BA22E4}

By Philip Plait

GREENBELT, Maryland. The scene is almost always the same. A lone astronomer
(or perhaps a team of two or three), using a small telescope, discovers a
moving object in the sky. With a swell of ominous music, the object is
determined to be several kilometers across and headed straight for Earth.
After some scrambling by the authorities, a team of intrepid heroes launches
into space, plants a nuclear bomb on the rock, and gets away just in time as
the asteroid explodes into a trillion pieces. The shattered remnants fall
into the Earth's atmosphere, burning away into nothing more harmful than a
spectacular fireworks show.

Does this sound familiar? It might, if you've watched any Hollywood movies
in the past 20 years or so. The 1998 pair of movies, "Armageddon" and "Deep
Impact," were both based on the idea that an object from space had Earth in
its crosshairs. Both had similar plots, though very different themes. "Deep
Impact" was a thoughtful movie, more about the emotions of the people on
Earth as they watch the comet approach. "Armageddon" was mostly about really
loud noises and gee-whiz special effects.

Still, the basic plotline has merit. Asteroids and comets do exist, and
their paths do cross ours. An impact of even a small object -- perhaps 10 or
so kilometers (6.2 miles) across -- could in all practicality wipe humans
off the face of the Earth. An impact like that, 65 million years ago, did
just that for the dinosaurs. Smaller impacts can be just as devastating. The
Tunguska impact had the force of about a 20 megaton bomb, yet the rock that
caused it was only 100 to 200 meters across. A theory released this past
month has it that the Dark Ages may have actually been caused by a cometary
impact. Professor Mike Baillie of Queen's University in Belfast says that
slow growth of tree rings in the year 540 indicates possible environmental
changes, and 13th century texts hint at the near passage of a comet in that
same year. Although this finding is highly speculative, it shows that we
don't understand comet and asteroid impacts well, or the effects they have
on the environment. If we don't want to suffer the same fate as the
dinosaurs, we'd better do something about it.

FULL STORY at
http://www.faz.com/IN/INtemplates/eFAZ/docmain.asp?rub={F1B72E2C-3783-11D4-A3AA-009027BA22E4}&doc={1104D9E7-AA5C-11D4-A3B2-009027BA22E4}

=============
(3) ECHOES OF ATLANTIS

From The Guardian, 25 October 2000
http://www.guardianunlimited.co.uk

Echoes of Atlantis

The catastrophe that wiped out Helike may have inspired a legend, reports
Iain Stewart

During the heyday of classical Greece, the city of Helike was the renowned
cult centre for worship of Poseidon, the god of the sea and of earthquakes.

Ironically, on a winter night in 373 BC, a violent earthquake and seismic
sea-wave (tsunami) destroyed and submerged the city. 

At the time of its destruction, Helike was capital of a con federation of
city states on the southern shores of the Gulf of Corinth, and was probably
located southeast of the modern city of Aigion, roughly 150 kilometres west
of Athens. Its precise location has long been the subject of debate among
historians and archaeologists. 

Ancient writers were insistent that the city lay off limits beneath the
waters of the Corinthian gulf, but modern marine surveys had repeatedly
failed to locate it there. Last week came the news that ruins of ancient
Helike had been uncovered onshore, three to four metres beneath the mud and
gravel of the Aigion coastal plain. 

There was perhaps forewarning that an earthquake was about to strike Helike,
but not of its scale. Writing in the 2nd-3rd century AD, Aelian described
how five days before the earthquake,   all the animals had left the city en
masse, much to the puzzled amusement of the local people. 

Ancient writers record that the earthquake which struck in the night
destroyed every single building in the city and that with the receding
waters of the tsunami, which came with the dawn, Helike was dragged down
along with every living person, the foundations of the city lost forever.  

Until, that is, excavations this summer. The possible discovery of Helike
was announced formally last week by Dr Dora Katsonopoulou, a Greek
archaeologist, and Dr Steven Soter, an astrophysicist from the American
Museum of Natural History. Their discovery was no accident. The locations of
the excavations had been carefully targeted following 12 years of subsurface
probing by boreholes and   geophysical imaging (radar and magnetometry) by
Soter and Katsonopoulou. 

Nevertheless, the nature of the finds still took both by surprise. In the
most important excavation, ruined walls and building foundations were found
buried below thick deposits of black peat and lagoonal and marine muds. The
discovery of these ruins entombed in a mixed blanket of terrestrial,
brackish and marine sediments is certainly consistent with a classical city
engulfed by a tsunami. 

However, the excitement is tempered by the realisation that only a few
square metres of the wide coastal plain has so far been excavated. 

For archaeologists, the prize is that, given the nature of Helike's demise,
the resurrected city may provide an unplundered, unmodified "time capsule"
from the classical era. Its shallow onshore location may allow the greater
part of the city to be excavated, giving Greece its very own Pompeii. 

For earthquake geologists, Helike offers a different prize. For us, the city
is fossilised result of a scale of seismic event that we know can strike the
earthquake-prone shores of the Aegean region but for which we have no modern
analogue. 

Killer earthquakes struck the Aigion shores in 1861 and 1995, but while they
caused widespread coastal submergence and some loss of life, neither of them
were of the enormity of the 373 BC event. 

So how often do such catastrophic sea-quakes occur in this region? 

In the early 1990s, I first went to the Helike area with that question in
mind. As part of a Royal-Society-funded honeymoon I studied the earthquake
fault that ruptured in 1861, and from raised shorelines along the Helike
coast I suggested that the same fault probably moved violently around the
time of the 373 BC event. 

In 1995, I turned my attention 100 kilometres northwards to another
earthquake-prone coast - the Gulf of Atalanti. Here, with two research
students (Vik Buck and Thomas Dewez), and in collaboration with Stella
Kortekaas (Coventry University) and Andy Cundy (now at the University of
Sussex), we   investigated the effects of coastal flooding triggered by a
damaging earthquake and tsunami in 1894. 

We were able to detect signs of this seismic disturbance in the modern marsh
sediments, so Soter and Katsonopoulou were interested in whether we could
detect the older but much larger Helike inundation event. 

This summer, funded by Brunel University and an EU project investigating
long-term seismic hazard in the Gulf of Corinth, I returned to Helike. I was
joined by Thomas, Andy and a new Brunel colleague Suzanne Leroy, professor
in palaeoenvironmental reconstruction. Working alongside Soter and
Katsonopoulou, our task was to drill shallow boreholes in a suspected former
lake bed. For the archaeologists, the lake was potentially the sacred grove
of Poseidon for which ancient Helike was famed. 

For us, the site lay a few tens of metres from the Helike fault, which we
suspected had ruptured during the 373 BC earthquake, and therefore the lake
may preserve an archive of that past earthquake activity. However, the
freshly recovered sediment cores have yet to reveal their story. 

Undoubtedly the most popular aspect of the Helike discovery will be its
association with the Atlantis legend. The story of Atlantis is first
recorded by the Athenian philosopher Plato, writing in the mid-fourth
century BC. 

Plato would have been in his early 50s when the 373 BC earthquake
obliterated the thriving city of Helike, and the tragedy would have been
reminiscent of a similar catastrophic event that struck mainland Greece
around the time of his birth. 

In 426 BC, a major earthquake caused widespread seismic destruction and
tsunami inundation around the Gulf of Evvia, including, in the Gulf of
Atalanti, the reported separation of Atalanti Island from the mainland. 

In his "dialogue" Timaeus, Plato recounts how "there occurred violent
earthquakes and floods" and then, in one awful day and night "the island of
Atlantis _disappeared in the depths of the sea." The parallels between
Plato's Atlantis and the 373 BC and 426 BC earthquakes are enticing,
particularly given that even after two and a half millenia of notable
historical seismicity in Greece, these two earthquakes stand out as
particularly catastrophic events. Perhaps the Atlantis legend is the real
legacy of Helike. 

Iain Stewart is a senior lecturer in geography and earth sciences at Brunel
University. His research is in earthquake geology, and he has recently
co-edited books on The Archaeology Of Geological Catastrophes and Coastal
Tectonics. 

Copyright Guardian Newspapers Limited

==============
(4) INTERNATIONAL SPACE FACILITIES TO ASSIST DISASTER MANAGEMENT

From European Space Agency <esaweb@esrin.esa.it>

A SINGLE TELEPHONE LINE TO MOBILISIE SPACE FACILITIES FOR NATURAL DISASTER
MANAGEMENT

As from 1 November countries where a natural or technological disaster has
occurred will be able to enlist emergency support from the space facilities
of the European Space Agency (ESA), the Centre National d'Etudes Spatiales
(CNES, France) and the Canadian Space Agency (CSA) by simply calling a
confidential telephone number.

The number will be notified to authorised users. As soon as a natural
disaster occurs, they will be able to call an operator at ESRIN (the ESA
establishment in Frascati, Italy), who will immediately contact the duty
engineer at ESA, CNES or the CSA.

The engineer will then deploy various space facilities of the three agencies
to assist the country where the disaster has struck: earth observation data
from SPOT, Radarsat, ERS and soon Envisat, facilities for telemedicine and
navigation (e.g. to track drifting buoys marking an oil slick), ground
infrastructures and archive pictures. Once launched, the Artemis and Stentor
communication satellites will also be available to relay data to the country
concerned.

Whenever called upon in a crisis, the three agencies will designate a
project manager to liaise with the country affected. Assistance will not be
confined to supplying satellite data, but will include processing and
interpretation as well.

The decision to set up this 24-hour hotline was taken on 25 October, at the
second meeting of the Board of the International Charter on Space and Major
and Disasters. The Charter was signed on 20 June this year by ESA and CNES,
with the CSA subscribing on 20 October. It is a far-reaching initiative to
promote cooperation by space system operators in the event of natural or
technological disasters. The Charter is open for signature by satellite
operators anywhere in the world. All partners undertake to cooperate on a
voluntary basis, with no exchange of funds between them.

For further information, please contact:
ESA press service: Franco Bonacina, tel: +00.331.53.69.71.55, fax
+00.331.53.69.76.90
CNES press service: Julien Guillaume, tel: +00.331.44.76.76.87, fax
+00.331.44.76.78.16
CSA press service: Anna Kapiniari, tel: +1.450.926.4350 - fax
+1.450.926.4352

=============
(5) WHEN IS A PLANET NOT A PLANET?

From Andrew Yee <ayee@nova.astro.utoronto.ca>

Office of News & Information
University of Pittsburgh
Pittsburgh, Pennsylvania

Contact:
John Fedele, fedele@univ-relations.pitt.edu, 412-624-4148

10/26/2000

When is a planet not a planet? Researchers see stars instead

PASADENA -- More than half of the recently detected extrasolar planets
appear not to be planetary objects at all, according to a preliminary
astrometric study conducted by researchers at the University of Pittsburgh's
Allegheny Observatory, the Lunar and Planetary Institute, and the Korea
Astronomy Observatory. The study is being presented at the Division for
Planetary Sciences of the American Astronomical Society meeting,  October
23-27, in Pasadena, California.

The study suggests that the companions are not planets, but brown dwarfs
(objects more massive than planets but smaller than stars), double stars, or
low-mass stars. The confusion arises because of the inability of the radial
velocity techniques, the basis of the original announcements, to determine
the masses of the companions. Radial velocity observations
cannot distinguish between a planet in an orbit that is viewed nearly edge
on from a brown dwarf or stellar companion in an orbit that is nearly in the
plane of the sky.

George Gatewood of the University of Pittsburgh's Allegheny Observatory,
Inwoo Han of the Korea Astronomy Observatory, and David C. Black of the
Lunar and Planetary Institute used astrometric data from the European Space
Agency (ESA) Hipparcos spacecraft, as well as radial velocity data,
to determine the inclination of the companion orbital planes to the
line-of-sight of the observer and thus to determine masses for the proposed
extrasolar companions.

"A striking result is the finding that orbital inclinations of the systems
studied are extremely low -- that is, the orbital planes of these companions
appear to be oriented nearly face on to the observer," said Black. "This
contradicts the assumption that the line-of-sight angle is
random in the radial velocity studies. It suggests that radial velocity
studies that have reported detection of low-mass companions may be biased
toward small inclinations in their selection of target systems."

"Part of the problem arises because masses smaller than that of Jupiter are
very difficult to detect, thus most of the objects that have been detected
and are suspected to be planets have masses greater than that of Jupiter,
the most massive planet in our solar system," said Gatewood.
"Until very recently, there were few known objects between one Jupiter in
mass and 80 times as much, and those are small stars."

Now that some objects in this mass range have actually been discovered,
astronomers are as confused as everyone else about what to call them,
Gatewood said. "The answer has to do with how they form, but that is
difficult to determine. Unfortunately, some astronomers have started
calling objects less than 10 Jupiters in mass 'planets', a sort of mystical
dividing line. To be scientifically correct, we should just call these
objects 'substellar.' "

In reducing the data to determine the companion orbits, the authors arrived
at four groupings of objects ordered by increasing value of the ratio of the
estimated orbit's semi-major axis to its standard error.

Nine stars are estimated to have companions with true masses of 10-15
Jupiters or less. This is slightly higher than the minimum masses given by
the radial velocity studies for these stars, but not excessively so.

A second group of 11 stars appear to have companions in the range of 15-80
Jupiters, masses substantially higher than the radial velocity results,
which are thus likely to be brown dwarfs rather than planets.

A third group of four stars yields companion masses that are clearly
stellar, probably M dwarf stars, although statistical artifacts have not
been completely ruled out.

A final group of six will require additional astrometric observations before
companion masses and inclinations can be determined with certainty.

An independent study by Mayor and colleagues (Halbwachs et al. 2000, also
using Hipparcos data) of systems discovered by radial velocity searches with
minimum masses in the brown dwarf range, shows a similar strong tendency (7
of 11 objects) toward systems with very low inclination
angles.

This result obtained from combining astrometric data with the radial
velocity findings is consistent with earlier studies that have noted that
the orbital periods and eccentricities of so-called "extrasolar planets" are
distributed in a way that is statistically indistinguishable from binary
stars. This suggests that many, perhaps most, of the systems that have been
identified as having planetary companions are indeed stellar or brown dwarf
binaries.

Han, Black, and Gatewood stress that this is a preliminary result. Its
intent is to guide future observers in their attempt to provide better data
for the study of the origins of our own planetary system. Their decision to
publish the initial results is based upon the surprising trend discovered by
the study, not by the result for any individual system. They have already
begun follow up studies with astrometric telescopic equipment at the
University of Pittsburgh's Allegheny Observatory.

============================
* LETTERS TO THE MODERATOR *
============================

(6) LATE EOCENE IMPACT EJECTA

From James Whitehead <jwhitehe@unb.ca>

Dear Benny,

Apparently the link to the EPSL paper I referred to in a recent CCNet
posting re: determining the provenance of minute quantities of upper Eocene
impact ejecta using isotopes, will not work for most of your readers who do
not subscribe to the Elsevier journals through the University of Toronto. My
apologies.

Interested viewers can read the article from my homepage instead, at:
http://www.unb.ca/web/geology/pdf.htm

Whitehead, J., Papanastassiou, D.A., Spray, J.G., Grieve, R.A.F. and
Wasserburg, G.J. 2000. Late Eocene impact ejecta: geochemical and isotopic
connections with the Popigai impact structure, Earth and Planetary Science
Letters 181, p.473-487.

---------------------------------------------
Dr. James Whitehead
Impact Geology Group
Planetary and Space Science Centre
Department of Geology
University of New Brunswick

=====================
(7) ASTEROID ARTICLE IN GERMAN NEWSPAPER (FAZ)

From Phil Plait <badastro@badastronomy.com>

Hi Benny--

I wanted to give you a head's-up: I have a semi-weekly astronomy column that
has just started in the German newspaper Die Frankfurter Allgemeine Zeitung.
The column will focus on the impact of astronomy on culture. The first two
articles I wrote are about searching for asteroids and what to do if we find
one headed  our way. The first article was published on the 25th, and a link
to the English version of the column can be found through my own website at
http://www.badastronomy.com/zeitung/index.html. The second part will be out
November 9 or so.

Note that an editing error in the 8th paragraph changed my intent somewhat;
I said originally that we know of 100 or NEAs which is only a fraction of
the total out there, but this was changed to imply that there are only 100
and we have seen a fraction of *those*. To a layman this may not make much
difference, but of course it's inaccurate. The mistake has been noted and
the staff there will fix  it soon. The link to my site at the bottom of the
article has a typo as well. The link I give above is correct. Note that I did *not* write the
bio of me! ;-)

I wrote a third article about asteroids discussing the role of scientists
and journalists when we a PHO is found. The column will not usually be about
asteroids (a fourth is about black holes, and I have others planned about
extrasolar planets, nomenclature in astronomy, etc), but this seemed like a
good topic with which to start.

I will link to the articles from my Zeitung webpage as they go live.

Thanks,

Phil Plait
*    *    *    *    *    The Bad Astronomer    *    *    *    *

==================
(8) NEW SCIENTIST FAILS TO CORRECT SENSATIONALIST SCARE STORY

From Michael Paine <mpaine@tpgi.com.au>

Dear Benny,

The cover story for the 7 October issue of New Scientist was called 'The
Drowning Wave'. It claimed the US east coast was under threat from a huge
tsunami generated by an undersea landslide that might occur in the Canary
Islands. I noted concerns about these claims in a CCNet posting
on 6 October - two scientists approached by BBC had expressed doubts about
the tsunami range estimates. I also wrote to the editor of New Scientist on
6 October pointing out those concerns. I had hoped it would be published
prior to the airing of the sensational(ised) Horizon program. I am
disappointed that New Scientist has not published my letter. You might wish
to publish it on CCNet.

regards
Michael Paine


The Editor, New Scientist

Sorry to spoil a sensational story but... The feature article 'The Drowning
Wave' greatly exaggerates the threat to the U.S. East Coast from a tsunami
generated near the Canary Islands. In July last year the Tsunami Society
held a conference on the subject of  "mega-tsunami" (conference proceedings
are available from http://epubs.lanl.gov/tsunami/ , including my paper on
tsunami from asteroid impacts). Although there is much work to be done on
modeling these giant waves it is evident that  many of the predictions from
the 1980s and early 90s overstated the long-range damage potential of
tsunami. Firstly many studies used an unusually high amplification
factor for calculating the height of the wave as it moved from deep to
shallow water. Factors of 40 have been quoted but these only occur in very
unusual locations such as parts of Hawaii and Japan. A more typical factor
is three. In other words, the run-up height of the tsunami onto
the shore is usually no more than about 3 times the height of the wave in
deep water. The second issue is the rate of dissipation of the tsunami over
the first few hundred kilometres. Multiple complex waves are usually
generated by the mega-tsunami event (such as an asteroid
striking the ocean or a large undersea landslide) and these tend to travel
at different speeds so the wave energy becomes dissipated. I have been in
touch with Charles Mader, a tsunami expert from Hawaii and Hermann Fritz,
who did some of the brilliant modeling work for the potential volcano
collapse mentioned in your article. They are both concerned that the
modeling only covered the initial wave characteristics - the first few
minutes.  Fritz told the BBC that the
waves would decrease and transform massively as they moved into the deep
water of the Atlantic. He said he did not make any statements regarding the
transoceanic wave characteristics. Mader confirmed the doubts about large
waves crossing the Atlantic -- he told Horizon that a La Palama
landslide would not be a threat to the U.S. -- but it appears that the BBC
ignored the advice of both scientists. The latest research suggests that it
would require an asteroid at least a kilometre in diameter to generate
tsunami that would be highly destructive across an entire ocean. An impact
that size would, of course, give the human race other problems beside
tsunami to think about. For smaller asteroids, and undersea landslides, the
waves become small by the time they cross an ocean and they only pose a
threat to highly vulnerable locations such as parts of Hawaii. The situation
is quite different for shorelines close to the event, such as occurred in
New Guinea in 1998. Here the waves did not have time to dissipate and water
reached more than 10 metres in height as it swept through the coastal
villages. There are concerns about tsunami generated by undersea landslides
off the U.S. continental shelf (for example see
http://www.nsf.gov/od/lpa/news/press/00/pr0038.htm ) and I have concerns
about a similar threat to Sydney's coastline, but destructive tsunami from
the other side of the ocean are highly unlikely.

Michael Paine
My research on "mega-tsunami" is described at
http://www1.tpgi.com.au/users/tps-seti/spacegd7.html

===============
(9) AND FINALLY: LEAKED DRAFT DOCUMENT CLAIMS GLOBAL WARMING 'WORSE THAN
FEARED'

From the BBC Online News, 30 October 2000
http://news.bbc.co.uk/hi/english/sci/tech/newsid_996000/996115.stm

By environment correspondent Alex Kirby

A draft report prepared for the world's governments says that the Earth may
heat up much more than current forecasts suggest.

The report, by scientists from the Intergovernmental Panel on Climate Change
(IPCC), says average global temperatures could rise twice as much as they
thought earlier.

It foresees a possible rise of 6C above 1990 levels. Five years ago, the
IPCC was predicting a probable maximum increase of 3C.

Scientists believe the level of carbon dioxide emissions being forecast in
the report could trigger the mass death of forests and significant rises in
sea levels, as well as crop failures and extreme weather.

Fossil fuels

The report is only a draft, and it is liable to be altered before
publication next May.

But it is bound to loom large at next month's meeting in the Netherlands of
the countries which have signed the Kyoto Protocol, the international
agreement on tackling climate change.

That commits signatories to collective cuts in greenhouse gas emissions of
5.2% below their 1990 levels by some time between 2008 and 2012.

Many scientists say Kyoto is only a modest start, and that cuts in emissions
of the main greenhouse gas, carbon dioxide (CO2), will have to reach 60% or
more in the next half-century to keep climate change within tolerable
bounds.

Climate science

The draft IPCC report concludes that the burning of fossil fuels and other
forms of pollution caused by human activities have "contributed
substantially to the observed warming over the last 50 years".

FULL STORY at
http://news.bbc.co.uk/hi/english/sci/tech/newsid_996000/996115.stm



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