Impact Events in the Holocene

 Much like the prolonged and severe climate conditions of the Younger Dryas, although only less so, were a number of periods of climate deterioration throughout the Holocene. A closer examination of three of these intervals provides insight into the likely cause. Specifically, the three time periods discussed here are the better documented, but at the same time most dramatic of the climate shifts, at least in the mid to late Holocene. 

     The three intervals are:
1) An approximately two hundred year-long cold and dry period that occurred in the mid 23rd century BC.
2) An almost equally severe but much less lengthy cold/arid time that was a part of the European Dark ages; this during the early to mid 6th century AD.
3) And finally, a more controversial (as to cause), climate downturn within the 17th century BC.

     As these three intervals share many of the same characteristics, they provide the basis for determining their most likely cause. The first fairly obvious feature of all three events, was the sudden onset of cold and arid conditions, occurring as they did with a definite synchroniety. This strongly suggests that the atmosphere be involved; this is because of the teleconnection of the climate changes to other parts of the world at such a rapid rate. This is one common signature. There are others that include: increases in both nitrates and ammonium in high-resolution proxy such as ice cores derived from Greenland. This, in itself, is an unusual occurrence, as most often nitrates and ammonium increase when biological activity becomes greater. This occurs during warmer, not colder climate conditions. The way in which nitrates increase in the distinctive cold periods examined here is through sudden rises or spikes. And though the ammonium levels also increase, they do so not quite as quickly but for longer periods. Detailed examination of these and a number of other prominent earlier cold periods also suspected of a common forcing mechanism displays increases in two radionuclides: carbon 14 and Beryllium 10. Concurrent increases of these two elemental forms again hints at an atmospheric trigger for the events discussed here.

     Consider the first of the three cold intervals, a fascinating period a little over 4,000 years ago. Well- established civilisations in the Mediterranean, India and Asia all suffered collapse or interruption. The city-state of Tell Leilan, a part of the Akkadian Empire (in what is now a part of Syria) saw a mass exodus of people at this time (1). Some exciting research by geologist Dr. Marie Agnes-Courty and her observations of “fine sand-sized well sorted spherules of silica, silicates and fibro- calcites as well as aggregates of densely packed crystals and exogenous angular fragments of a crystalline igneous,” were all a feature of an anomalous layer (2). The result, an “uncommon layer of dense packing of sand-sized, very porous aggregates that suggest disintegration, as if by an “air blast” (3).  In addition to this, not that far away in what today is southern Iraq, is the discovery of an approximately three kilometre wide crater that may date from the same time as the unusual layer extracted from the soils of Tell Leilan (4).  Elsewhere too, proxy from North America (pollen) and tree rings from western Europe, low lake levels in the Mediterranean, and also Africa, are all suggestive of a very significant cooling that reached the largest temperature deviation of about four degrees Celsius in Asia (5,6,7).

     Also, there seems to be little doubt as to the origin of the mid-6th Century AD climate downturn. Perhaps no more than a decade in length (536 to 545 AD), this was a time of greatly diminished sunlight. Originally at least, a historian and author by the name of David Keys attempted to make a case for the great Southeast Asian volcano Krakatoa as the cause for this time of climate cooling (8). This as the principle cause is now highly unlikely, what with only modest amounts of dust produced by all but the mega-volcanic eruptions, and the last one of these, (Toba) took place some 74,000 years ago, also in Asia. The extent of the dust cloud that affected the Mediterranean region in the years 536 to 545 AD was so extensive as to dim the sun to approximately 10% of normal light; this for a period of up to eighteen months (9). The fact that so much dust was present in the atmosphere is also shown by observations in far off China where the prominent star, Canopus was obscured for much of 536 AD (10). These important features go a long way in proving that far more than volcanic dust was involved in causing the cooling of the climate at this time.

     Finally, the other cold interval that remains somewhat more controversial as to cause, is the cold/arid period of the early 17th Century BC. Evidence in the form of very narrow tree rings detected in the Bristlecone Pine trees of western North America have been linked to a volcanic eruption of the caldera of Thera (Santorini), in the eastern Mediterranean (11). The date when Thera erupted so violently was originally linked by some scientists to the downfall of the Minoan civilisation (12). Since these earlier findings, more recent research has established that this most major event occurred in 1628 BC; due to a carbon dateable olive branch having been recovered from the tephra layer produced by the eruption (13). However, there does remain controversy as to the main cause of the more than decade long cold period of the early 17th Century BC. Observations by Babylonian astronomers in the vicinity and downwind of Thera tell of a dust veil that was of sufficient thickness to hide the usually very bright object Venus for a period of nine months and four days (14). What’s more, in far off China, the observation in 1630 BC of two suns, one in the west and the other in the east strongly suggests that one of the objects was a comet (15). Geologist Robert Schoch in fact concludes as much when he suggested that there was a significant comet encounter at this time (16).

     These are but a few of the suspected events, suggested as comet caused throughout the Holocene. There were strong signs of a comet presence at about 44 BC and 200 BC. Finally, there are a number of other suspected cosmic events, one not long after the end of the Younger Dryas, approximately 11,400 BP., another at 10,400 BP, and a third very severe event about 8200 BP. (17,18). Also, some interesting research by Dr. Mike Baillie, professor of Palaeoecology at Queen’s University in Belfast suggests a link between what Dr. Baillie deems the Black plague of the late 1340’s early 1350’s rather than being associated with rats now being associated with a cosmic origin (19). Elaborating, Dr. Baillie has determined that rather than the plague spreading generally north-westerly from origins that may have been in central Asia or Africa, and then spreading, possibly via trade routes from the Black Sea, then into Europe via northern Italy and southern France (20).

     All of these climate intervals appear to share the characteristic of being cold periods with a very sudden onset. The cause in each case appears to be cosmic in origin and the nature of the event is that of “strong cometary dustings associated with multiple comet bombardments (21). Dr. William Napier believes that originally that many of the comets are derived from the very distant Oort cloud. Predominately, this occurs in response to Galactic Tides or very large nebulae affecting some of the comets and slinging them into our solar system (22). What is most distinctive is Dr. Napier’s belief at present the inner solar system and ultimately the Earth are being affected by one of these active periods (23). This of course has a great many ramifications for the earth’s future; a situation that appears to be a woefully underestimated threat by many scientists, including those at NASA.

REFERENCES:

  1. Weiss, H., The Genesis and Collapse of Third Millennium North Mesopotamia Civilisation. Science vol. 261, 1993. 995-1004.
  2. Courty Marie – Agnes, from Internet site: http//www.knowledge.co.uk./sislabastralcountry.htm causes.
  3. Ibid.
  4. Schoch, Robert, M., 2003, Voyages of the Pyramid Builders, Jeremy P. Tarcher Press, New York, U.S.A.
  5. Viau, Andre E. et al., Widespread Evidence of 1500 yr Climate Variability in North America During the Past 14,000 Yr., Geology Vol 30 #5., 2002, 455-458.
  6. Schoch, Robert, M., 2003, Voyages of the Pyramid Builders, Jeremy P. Tarcher Press, New York, U.S.A.
  7. Hong, Y.T., et al., Response of Climate to Solar Forcing Recorded in a 6,000 – year Oxygen 18 Time –Series of Chinese Peat Cellulose, The Holocene Vol 10.1. 2000, 1-7.
  8. Keys, David, 2000, Catastrophe: An Investigation into the Origins of the Modern World, Arrow Books, London, England.
  9. Baillie, Mike, 1999, Exodus to Arthur, Catastrophic Encounters with Comets. B.T. Batsford, London, England.
  10. Ibid., 61.
  11. La Marche, V.C., and K.K. Hirschboeck, Frozen Rings in Trees as Records of Major Volcanic Eruptions, Nature, Vol. #307, 1989, 121-126.
  12. Baillie, Mike, 1999, Exodus to Arthur, Catastrophic Encounters with Comets. B.T. Batsford, London, England.
  13. Friedlich, Walter L., Santorini Eruption Radiocarbon Dated to 1627 – 1600 BC. Science, Vol. 312, 2006, 548.
  14. Schoch, Robert, M., 2003, Voyages of the Pyramid Builders, Jeremy P. Tarcher Press, New York, U.S.A.
  15. Baillie, Mike, 2006, New Light on the Black Death – Cosmic Connection, Tempus Publishing Ltd., Stroud, Gloucestershire, England.
  16. Schoch, Robert, M., 2003, Voyages of the Pyramid Builders, Jeremy P. Tarcher Press, New York, U.S.A.
  17. Bjorck, Svante et al., Synchronised Terrestrial – Atmospheric Deglacial Records around the North Atlantic. Science Vol. #274, 1996, 1155-1160.
  18. Bjorck, Svante et al., High Resolution Analyses of an Early Holocene Climate Event May Imply Decreased Solar Forcing as an Important Climate Trigger. Geology Vol. #29 #2, 2001, 1107-1110.
  19. Baillie, Mike, 2006, New Light on the Black Death – Cosmic Connection, Tempus Publishing Ltd., Stroud, Gloucestershire, England.
  20. Ibid, 12.
  21. Napier, W. M. 2009, Comets Catastrophes and Earth’s History, Journal of cosmology Vol. #2: 344-355.
  22. Ibid. 346.
  23. Ibid. 350..