Re: New archaeological evidence casts doubt on mega-tsunami theory of Minoan collapse

From: Eric Stevens (eric.stevens_at_sum.co.nz)
Date: 01/09/05 

Date: Mon, 10 Jan 2005 00:20:49 +1300

On 8 Jan 2005 20:52:40 -0800, "Daryl Krupa" <icycalmca@yahoo.com>
wrote:

>
>Eric Stevens wrote:
>> On 7 Jan 2005 16:59:53 -0800, "Daryl Krupa" <icycalmca@yahoo.com>
>> wrote:
>>
>> >
>> >Eric Stevens wrote:
><snip>
>> >> Edward Bryant in his book 'Tsunai, the underrated hazard'
>[Cambridge
>> >> University Press, ISBN 0 521 77244 3 or 0 521 77599 X] devotes
>> >several
>> >> pages (with citations) the the evidence for the tsumai caused by
>the
>> >> Santorini eruption of 'around 147 B.C.'. This includes a diagram
>> >> showing the tsunsmi wave energy as it radiated from Santorini.
>There
>> >> are three principal radial beams of wave energy concentrated by
>> >> refraction. (1) 255 degrees, (2) 180 degrees and (3) 90 degrees.
>> >> Similarly there are three regions ientified as 'Tsunami wave
>energy
>> >> dispersed by refraction. (A) between 285 degrees and beam (1),
>> >between
>> >> beams (1) and (2), and betweens beams (2) and (3). Clearly the
>impact
>> >> of the tsunami (plural) was patchy.
>> >>
>> >> I am not sure how Bryant's interpretation matches up with those of
>> >the
>> >> paper I originalyl referred to.
>> >
>> >Not much of a match, I'm afraid.
>> >A 90 degree direction is definitely contraindicated.
>>
>> Unfortunately, Bryant seems to think there is evidence supporting
>> such a direction. I can't find his diagram on the web.
>
>But you can find a couple of very disparaging book reviews.

One a hatchet job and the other more crical of editorial aspects.
>
>Here are a couple of excerpts from one of them (page 31 at the
>pdf URL below, ( http://www.dnr.wa.gov/geology/tsuinfo/2002-01.pdf )
>titled
>"Tsuinfo Alert Volume 4, Number 1, February, 2002"),
>by Guess Who?

  "Costas Synolakis, University of Southern California, Los Angeles,
   USA, and Gerard J. Fryer, University of Hawaii, Honolulu, USA
>
>" The book is so flawed by errors, omissions, confusion,
>and unsupported conjecture that we cannot recommend
>it to anyone. "
>
>" First are the errors. ...
>The death toll of the 1975 Kilauea tsunami is claimed as
>16, but was actually two. The death toll of the 1792 tsunami
>from Unzen is claimed at 4300, but was about 15,000.

Bryant actuall quotes a figure of 14,524 and cites the National
Geophysical Data Centre and World Data Centre A for Solid Earth
Geophysics 1998 and Intergovernmental Oceanographic Commission 1999.

>The 1923
>great Tokyo earthquake is claimed to have been "cycloneinduced."

On page 192 Bryant is discussing the effect of tidal surges etc on
pore pressures and its role in submarine slumping. He goes on to
expand on this by writing:

  "Changes in sea level do not have to be large to induce failure.
   Storm surges associated with the passage of a tropical cyclone
   can load and deload the shelf substantially. For example, along
   the East Coast of the United States, 7-rn-high surges are common.
   The resulting increase in weight on the seabed can be 7.2 x 106
   tonnes kxn2. If this is preceded by deloading due to the drop in
   air pressure as the cyclone approaches shore, than the tota
   change in weight can amount to 10 x 106 tonnes km—2. In areas
    where the Earth's crust is already under strain, this pressure
    change may be sufficient to trigger an earthquake. The classic
    example of a cyclone-induced earthquake occurred during the
    Great Tokyo Earthquake of 1923. A typhoon swept through the
    Tokyo area on 1 September and was followed by an earthquake,
    a submarine slide, and an 11m-high tsunami that evening. In all,
    143,000 people were killed. Measurements after the earthquake
    indicated that parts of the Sagami Bay had deepened by 100-200 m
    with a maximum displacement of 400 m. These changes are indicative
    of submarine landsliding. In Central America, the coincidence of
    earthquakes and tropical cyclones has a higher probability of
    occurrence than the joint probability of both events. Finally,
    failures on the submerged front of the Mississippi Delta have
    occurred primarily during tropical cyclones.

>Such errors, and there are dozens of them, make
>the book worthless to scholars and misleading to newcomers. "
>
>" Second are the omissions. The slump source for the 1998
>Papua New Guinea tsunami has been positively identified
>and widely reported, but Bryant seems unaware of it:
>"No individual slump can be associated with the tsunami." "

The possibility of there having been a major slump was first presented
in July 1999 and published in August 1999, a year after the event. See
http://www.sciencenews.org/pages/sn_arc99/8_14_99/fob2.htm

However, the same article points out:

  "Some survey participants, however, discount the slump theory. Harry
   Yeh of the University of Washington in Seattle argues that
   simulations of a subsea quake can explain the tsunami's size.
   The team found evidence for small slides but no obvious signs of a
    giant slump, he says."

I don't think the matter had been satisfactorily resolved by the time
Bryant's book went to press in 2001. In fact, the last sentence of the
above quote is consistent with what Bryant wrote.
>
>" Third is the confusion. ...
>Some statements are confused beyond comprehension:
>"Seismic waves with surface magnitude of
>9-11 on the Richter scale
>caused faulting in shallow waters around the Gulf."
>
>" Fourth is unsupported conjecture. The third blast of
>Krakatau was the "largest sound ever heard by humanity."
>"In the Pacific Region there have been sixteen tsunami
>events in the last 2000 years in which submarine landslides
>were triggered by earthquakes killing 68,832 people."
>In coastal geomorphology (Bryant's area of expertise),
>every enigma apparently has a tsunami explanation.
>The gullible reader will be left with the impression that
>tsunamis are as common as thunderstorms. Almost everyone of
>Bryant's examples is controversial. "

Mainly because no one had previously considered looking for evidence
of such giant tsunami. There is no precedent.
>
>" Bryant dedicates his book "to the memory of J.[sic] Harlen
>Bretz." Like that lonely hero of the Channeled Scablands,
>Bryant apparently sees himself as the lone tsunami
>catastrophist battling a unformitarian establishment.

The authors of the review seem to be assisting to create that
situation. They forget that Bretz eventually turned out to largely
correct.

>(predictably, his description of catastrophism versus
>uniformitarianism reflects the usual geologist's misreading
>of nineteenth century history).
>While no convincing alternative to Bretz's flood was ever
>offered, though, Bryant goes out of his way to avoid
>consideration of the one phenomenon that handily explains
>most coastal features without the need for anything more
>exciting than the odd storm: sea-level change.
>Bryant makes the tacit assumption that sea level has always
>been where it is now. However, lift coastlines the few meters
>demanded by local isostatic adjustment to postglacial sea-level
>rise, and most of Bryant's enigmas simply evaporate.

Not when you take into account (1) Bryant does consider changes in sea
level and (2) the sites he has identified have been dated by one
method or another. In fact many have multiple datings which correlate
reasonably well.
>
>Maybe Bryant is right. Maybe there is a huge flux of
>bolides hitting the Earth to produce abundant "mega" tsunamis.

But that was but a minor part of his thesis, although it seems to be
the one which has enraged his critics. I suppose that I too would not
be happy that throughtout my professional carreer I had failed to
recognise that the landscape was littered with spectacular evidence
for events I had never dreamed of.

>A book as full of demonstrable errors as this one,
>however, is going to convince nobody and is a more underrated
>hazard than its title suggests. "
>
>by Costas Synolakis and Gerard J. Fryer
>
>http://www.dnr.wa.gov/geology/tsuinfo/2002-01.pdf
>
>You'll need access to _Nature_ for this one, which is
>less scathing:
>
>Satake, K.
>2002
>"Making waves on rocky ground"
>Book Review: Tsunami - The Underrated Hazard"
>Nature 415 p. 369
>doi:10.1038/415369a
>
>A precis:
>" arts of the book lack rigour and consistency; especially
>needed are a more comprehensive and better-organized index
>and a glossary of tsunami jargon from the many fields involved. "

I definitely agree with the criticism of the index but, for that, I
blame the publisher. The book was compiled with Quark XPress which is
more than capable generating any kind of index you like.
>
>Original Japanese here:
>
>http://www.google.ca/search?q=cache:YDnih5m524sJ:www.natureasia.com/japan/webspecial/tsunami/index.php+%22Tsunami,+the+underrated+hazard%22+review&hl=en
>
>OR
>
>http://tinyurl.com/6oy55
>
>>>From another equivocal review's abstract:
>
>" Many deposits and erosional features described and discussed
>as tsunami signatures have yet to be linked specifically with
>tsunamis.

True, if only for the reason that before Bryant no one had taken the
idea of such mega-tsunamis seriously.

>Cited references in the book do not necessarily support a
>tsunami origin for these features, because accepted scientific
>citation practices have not been followed.

That too is likely to be the fault of his editor. He does have a
several page list of refrences in the back of the book but no direct
linking of them to the text of the book. Instead, each chapter has a
list of the refrences upon which he has principally relied.

Apart from that, you have left out a critical section of that source:

  "Despite its shortcomings, this book should be on the library
    shelves of all marine geoscientists who study modern and
    ancient shorelines. However,...
>... it should be used with great circumspection, because
>the process:product relationships it assumes are equivocal. "

I always cross-check these things anyway. So too should the reader.

>
>Felton, E. Annea; Crook, Keith A.W.
>2003
>Evaluating the impacts of huge waves on rocky shorelines:
>an essay review of the book 'Tsunami - The Underrated Hazard'
>Marine Geology
>Vol: 197, Issue: 1-4, pp. 1-12
>DOI: 10.1016/S0025-3227(03)00086-0
>
>http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6V6M-48BC12C-2&_coverDate=06%2F15%2F2003&_alid=234982407&_rdoc=1&_fmt=&_orig=search&_qd=1&_cdi=5818&_sort=d&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=e2e40ace32fb15c8b752a4f21fe2d5e9
>
>OR
>
>http://tinyurl.com/4brvx
>
>OR
>
>http://tinyurl.com/566l3
>
>OR
>
>http://elsevier.lib.sjtu.edu.cn/cgi-bin/sciserv.pl?collection=journals&journal=00253227&issue=v197i1-4&article=1_etiohwotbtuh&form=pdf&file=file.pdf

 "Access not permitted"
>
>OR
>
>http://tinyurl.com/6qwva
>
>
>For my own later reference, there was another review:
>
>Journal of Quaternary Science
>Volume 18, Issue 6, Page 582
>DOI: 10.1002/jqs.778
>
>ref (no abstract, tho) @
>
>http://www3.interscience.wiley.com/cgi-bin/abstract/104554926/ABSTRACT

"No Abstract"
>
>I rather think that the Dominey-Howes' article in
>Journal of Volcanology and Geothermal Research
>is a better source of information on this subject.
>
>>>From the Conclusion section:
>
>" Re-examination of the original LBA tsunami hypothesis has
>demonstrated either that the arguments proposed were flawed
>(because of the findings of new geological evidence) or that
>they lack any substantive archaeological or geological evidence.
>Further publications supposedly demonstrating evidence for LBA
>tsunami (i.e. pumice on beaches) have also been critically
>reviewed and rejected since these papers are based on a
>misunderstanding of the hydrodynamics of tsunami wave propagation.
>Results of a geological investigation of over forty sites on
>Crete and Kos have failed to identify any evidence that may be
>associated with a LBA tsunami.
>If a LBA tsunami was generated, only a sparse geological record
>remains and such evidence may only be used to infer the action
>of near-field tsunami.
>It is likely that a LBA tsunami would have attenuated quickly
>within the Aegean archipelago. "
>
>>>From the Abstract:
>
>" The data are used to test the hypothesis that the LBA eruption
>generated an east Mediterranean-wide tsunami.
>It will be seen that no terrestrial geological evidence is
>identified.
>The paper re-examines the original arguments presented for
>LBA tsunami, challenging them because their founding
>assumptions are flawed.
>Together, the new data and the re-analysis of the original
>tsunami hypothesis indicate that there is insufficient
>evidence to demonstrate that any significant far-field tsunami
>propagated throughout the entire east Mediterranean as
>frequently purported. "
>
>Daryl Krupa
>

Eric Stevens

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